Psoroptes Research Articles

First case of bovine psoroptic mange in Scotland in over 30 years

Cattle scab diagnosed in an imported calfDandy-Walker malformation in small pedigree Suffolk flockCorynebacterium renale causing renal disease in pregnant ewesAtrophic rhinitis in a previously unaffected pig herdInfectious bronchitis diagnosed in...

A class of promising acaricidal tetrahydroisoquinoline derivatives: synthesis, biological evaluation and structure-activity relationships.

As part of our continuing research on isoquinoline acaricidal drugs, this paper reports the preparation of a series of the 2-aryl-1-cyano-1,2,3,4-tetrahydroisoquinolines with various substituents on the N-phenyl ring, their in vitro acaricidal activities against Psoroptes cuniculi, a mange mite, and discusses their SAR as well. The structures of all compounds, including 12 new ones, were elucidated by analysis of UV, IR, NMR, ESI-MS, HR-MS spectra and X-ray diffraction experiments. All target compounds showed varying degrees of activity at 0.4 mg/mL. Compound 1 showed the strongest activity, with a 50% lethal concentration value (LC50) of 0.2421 μg/mL and 50% lethal time value (LT50) of 7.79 h, comparable to the standard drug ivermectin (LC50 = 0.2474 μg/mL; LT50 = 20.9 h). The SAR showed that the substitution pattern on the N-aromatic ring exerted a significant effect on the activity. The substituents 2'-F, 3'-F, 2'-Cl, 2'-Br and 2'-CF3 remarkably enhanced the activity. Generally, for the isomers with the same substituents at different positions, the order of the activity was ortho > meta > para. It was concluded that the target compounds represent a class of novel promising candidates or lead compounds for the development of new tetrahydroisoquinoline acaricidal agents.

Acaricidal activity of usnic acid and sodium usnic acid against Psoroptes cuniculi in vitro.

Usnic acid, a major active compound in lichens, was first isolated in 1884. Since then, usnic acid and its sodium salt (sodium usnic acid) have been used in medicine, perfumery, cosmetics, and other industries due to its extensive biological activities. However, its acaricidal activity has not been studied. In this paper, we investigated the acaricidal activity of usnic acid and sodium usnic acid against Psoroptes cuniculi in vitro. After evaluating the acaricidal activity and toxicity of usnic acid and sodium usnic acid in vitro, the results showed that at doses of 250, 125, and 62.5 mg/ml, usnic acid and sodium usnic acid can kill mites with 91.67, 85.00, and 55.00% and 100, 100, and 60.00% mortality after treatment 24 h. The LT50 values were 4.208, 8.249, and 16.950 h and 3.712, 7.339, and 15.773 h for usnic acid and sodium usnic acid, respectively. Sodium usnic acid has a higher acaricidal activity than usnic acid, which may be related to the difference in their structures.

Clinico-pathological and therapeutic evaluation of Black Bengal goats (Capra hircus) infested with Psoroptes cuniculi mange.

The objective of the present study was to investigate the clinico-pathological changes and therapeutic evaluation of gamma-benzene hexachloride and cetrimide along with vit A, D3, E and H in Black Bengal goat infested Psoroptes cuniculi mange. The study was conducted on 14 Black Bengal goats; 6 clinically infested with Psoroptes mange (group I) and 8 healthy goats (group II). Haemato-biochemical profile viz., haemoglobulin concentration, packed cell volume, total leukocyte count, albumin and albumin globulin ratio revealed significantly (P<0.05) decreased level; whereas, globulin, alanine aminotransaminase, aspartate aminotransaminase, serum creatinine and blood urea nitrogen level were significantly (P<0.05) increased in goats of group I animals as compared to healthy control (group II) on day 0. Gamma-benzene hexachloride and cetrimide along with adjunct therapy (group I) showed parasitological recovery on day 21 while complete elimination of clinical signs observed on day 28 of post-therapy in all clinical cases.

Effect of Ivermectin against Psoroptic mange in rabbits

The present report is on Psoroptic mange infestation in rabbits. Out of 126 rabbits in a farm 34 were infested. Observed clinical signs were alopecia, crusts formation, superficial and deep skin fissures and itching. Distribution of lesions was noticed around the base of ears, margins of the ears and face. Skin scrapings from infested rabbits were examined and eggs, larvae, nymphs and adult mites were recovered. The infected rabbits were treated with ivermectin @ 200µg/kg body weight first day subcutaneously followed by orally once in 48 hours along with antibiotic and supportive therapy. Improvement in the condition was noticed after 4 th day of therapy.

Isolation and identification of acaricidal compounds in Eupatorium adenophorum petroleum ether extract and determination of their acaricidal activity against Psoroptes cuniculi

We used multiple silica gel column chromatography and thin-layer chromatography coupled with 1H nuclear magnetic resonance (NMR) and 13C NMR to separate and identify the active acaricidal ingredients in Eupatorium adenophorum petroleum ether extract. The acaricidal activity of each compound was tested against Psoroptes cuniculi in vitro. Three compounds had strong acaricidal activity against P. cuniculi in vitro. The insecticidal effect of 0.5% compound 9β-hydroxy-ageraphorone was better than the insecticidal effect of fenvalerate, and compounds 9-oxo-ageraphorone and 9-oxo-10,11-dehydro-ageraphorone exhibited higher insecticidal effects than 9β-hydroxy-ageraphorone. Thus, the E. adenophorum petroleum ether extract contains an effective composition of acaricides that could potentially be developed as a promising plant-origin acaricide.

Evaluating troponin C from Psoroptes cuniculi as a diagnostic antigen for a dot‐ELISA assay to diagnose mite infestations in rabbits

The mite Psoroptes cuniculi is globally widespread and has a serious impact on commercial rabbit breeding. In China, diagnosis of P.cuniculi is currently based on conventional clinical methods that entail numerous disadvantages, including their failure to diagnose subclinical infections. Hence, alternative measures are required, and dot-ELISA is one of the most promising strategies. We cloned and expressed the recombinant P.cuniculi troponin C gene for use as a basis for novel dot-ELISA assay to detect P.cuniculi infections in rabbits. This amplified sequence encoded a 153 amino acid protein of 17·6kDa and theoretical pI 4·18 without signal peptide. The recombinant troponin C of P.cuniculi is an outer membrane protein and may also be a new P.cuniculi allergen. Results of dot-ELISA test showed that this novel assay had more than 90% sensitivity but low specificity in distinguishing infections with P.cuniculi or Sarcoptic scabiei, despite very high agreement between observers (97-99%; κ values ranged from 0·95 to 0·98 for inter- and intra-observer variability test). This study showed that this novel method, at present, lacks diagnostic utility. Therefore, although simple serological assays such as dot-ELISA show great promise as diagnostic tools, we suggest that troponin C is not a suitable diagnostic antigen candidate.

The oxidative status and inflammatory level of the peripheral blood of rabbits infested with Psoroptes cuniculi

BackgroundPsoroptes cuniculi can parasitise the ear canal of the rabbit, and cause the afflicted animals to cease feeding and become severely debilitated, sometimes resulting in death. In this study, we examined the oxidative status and inflammatory level of the peripheral blood of rabbits infested with Psoroptes cuniculi and investigated the pathogenesis of this disease.MethodsA total of 24 rabbits were divided into a healthy rabbit group and two infested rabbit groups. After weighing the rabbits, approximately 5 ml of blood was obtained from each animal. Then, the blood serum was extracted and used to assess the levels of antioxidant enzymes and inflammatory factors.ResultsCompared to the healthy rabbits, the activities of catalase and glutathione-S-transferase and the level of malonyldialdehyde were increased, but the activity of superoxide dismutase was reduced in the infested rabbits. At the same time, a variety of inflammatory cells were activated, and the levels of inflammatory factors such as prostaglandin E2, interleukin-6, interleukin-8 and transforming growth factor-β1 were increased in peripheral blood.ConclusionAnimal acariasis was associated with immunosuppressive disorders and inflammatory reaction. These results advance our understanding of the pathogenesis of Psoroptes cuniculi infestation in rabbits and can help guide the effectual treatment of this disease in clinics.

Técnica de lavagem do conduto auditivo para medir a infestação por Psoroptes cuniculi em caprinos

Esta pesquisa teve como objetivos avaliar a eficiência da técnica do jato de água, com 50 e 100ml de água, para determinar a prevalência da infecção por Psoroptes cuniculi e estimar o grau de infestação para estudos da dinâmica populacional. O estudo foi realizado no matadouro municipal da cidade de Patos, Paraíba, com 30 caprinos de ambos os sexos e idades variadas. O conduto auditivo esquerdo de cada caprino foi lavado com 100ml de água e o direito, com 50ml. Os ácaros coletados na lavagem e os ácaros obtidos após a abertura dos condutos auditivos foram contados e identificados de acordo com o estádio do ciclo biológico do parasito. Mediante a técnica da lavagem com 100mL, foi identificado o parasita em 22 (91%) dos 24 condutos infectados e, na lavagem com 50mL, foi identificado em 18 (78,3%) de 23 condutos infectados (P&gt;0,05). Após a abertura e contagem do total de ácaros, verificou-se que, na lavagem, haviam sido recuperados de 19% a 35% dos ácaros de todos os estádios de desenvolvimento, exceto para o estádio de ovo, que foi de 11% a 15%, não havendo diferença estatística significativa (P&gt;0,05) entre as taxas de recuperação com 50 e 100mL de água. Conclui-se que a técnica da lavagem do conduto auditivo é eficiente para estudos da prevalência da otocariase, porém, para estudos de dinâmica populacional, recomenda-se a abertura dos condutos auditivos e a contagem de todos os ácaros presentes.

Identification and Prevalence of Ectoparasites in Cattle and Sheep in and Around Bishoftu Town, Central Ethiopia

A cross-sectional study was conducted from October, 2010 to May, 2011 on a total of 384 cattle and sheep to identify the major ectoparasites and to determine their prevalence in and around Bishoftu town, central Ethiopia. Out of 202 cattle and 182 sheep examined for ectoparasites, 95 (47.0%) cattle and 73 (40.1%) sheep were found to be infested with one or more ectoparasites. Overall eight genera of ectoparasites belonging to ticks (Boophilus, Amblyomma, Rhepicephalus and Hyalomma), lice (Damalina and Linognathus) and mange mite (Demodex spp and Psoroptes spp) were encountered in the study area. Prevalence of tick infestation was 35.2% (71/202) in cattle and 26.9% (49/182) in sheep. Among the risk factors assessed, female animals (cattle: χ2=5.4, P=0.020; sheep: χ2=5.5, P=0.019) and production system (cattle: χ2=29.4, P=0.000; sheep: χ2=10.3, P=0.001) were significantly associated with prevalence of tick infestation. The prevalence of pediculosis was 8.9% and 12.6% in bovine and ovine, respectively. Sex (χ2=19.3; P=0.000) and breed (χ2=4.6; P=0.033) in cattle, and production system in both cattle (χ2=5.5; P=0.020) and sheep (χ2=6.4; P=0.040) were found to be significantly associated with the prevalence of pediculosis. The prevalence of demodicosis and psoroptic mange in cattle was 6.6% and 0.6%, respectively. However, the only mange mite species encountered in sheep was Psoroptes with the prevalence rate of 2.2%. Age in cattle (χ2=14.0; P=0.000) and sheep (χ2=3.8; P=0.040), and body condition in cattle (χ2=7.7; P=0.021) were found to be significantly associated with the prevalence of mange mite infestation. The present study revealed that widespread occurrence of ectoparasites in cattle and sheep in the study area, and the major ectoparasites identified were tick, lice and mange mite, thus, improved management practice and well-coordinated control interventions are required.

Evaluation of acaricidal activity of different seed oils on Psoroptes cunniculi (Delafond, 1859) (Cheyletidae) in rabbits

Context: Mange is one of the common animal diseases worldwide. Lack of tools to evaluate mange severity in animals and to demonstrate its importance has hindered the efforts of veterinarians to control the disease. Objective: This study was design to evaluate the efficacy of oils from five plants against Psoroptes cuniculi in rabbits. Materials and methods: Seed oils of Treculia africana Decne (Moraceae), Pentaclethra macroplylla Benth (Mimosidae), Calophyllum inophyllum Linnaeus (Calophyllaceae), Garcinia mangostana Linn (Guttiferae) and Monodora myristica Gaertn (Annonaceae) were extracted with hexane. Acaricidal activity of the plants and ivermectin was investigated in six groups (five per group) of rabbits naturally infested with psoroptic mites to determine their relative efficacy. Single dose of the oils were applied topically on the affected parts every morning for six weeks and skin scrapings collected weekly to determine mite number. Results: Significant (P < 0.05) decrease in the number of mites (from 1.7 to 0.18 per cm 2 ) was observed in C. inophyllum, which is the most active oil, six weeks post-treatment. Similarly C. inophyllum demonstrated the best activity (89.41%) followed by G. mangostana (88.89%), P. macrophylla (81.45%), T. africana (40.10%) and M. myristica (24.76%). The weight gain of rabbits treated with oil of Calophyllum inophyllum was significantly higher than the rabbits treated with other seed oils and ivermectin. The mean recovery response of C. inophyllum seed oil was better than the other oils. Discussion and conclusion: The results indicate that three of the seed oils could be useful alternatives to synthetic acaricides.

Clinical efficacy of 9-oxo-10, 11-dehydroageraphorone extracted from Eupatorium adenophorum against Psoroptes cuniculi in rabbits

Animal acariasis is one of the important veterinary skin diseases. Chemical drugs have been widely used to treat and control this kind of disease. But many chemicals control could increase resistance in target species, toxicity and environmental hazards. We found that the 9-oxo-10, 11-dehydroageraphorone (euptox A) extracted from E. adenophorum has strong toxicity against P. cuniculi in vitro, but the in vivo acaricidal actions of euptox A have yet to be investigated. A 14-day experiment was performed using rabbits that were naturally infested with P. cuniculi on a farm. Rabbits were randomly divided into five groups; animals in groups A, B and C were treated in each ear topically with 4.0 ml of 2.0 and 1.0 g/L (w/v) euptox A, respectively. Animals in groups D and E were treated with ivermectin (by injection; positive controls) and glycerol with water only (by embrocation; negative controls), respectively. Each rabbit was treated twice with separate treatments on days 0 and 7. Rabbits were observed daily and detailed examinations were performed on days 0, 7 and 14, to inspect the presence or absence of mites and scabs/crusts. Seven days after the initial treatment, the mean clinical scores (presence of scabs/crusts) decreased from 3.48, 3.37, 3.43 and 3.45 to 0.37, 0.42, 0.78 and 0.38 in the ears of animals in groups A, B , C and D, respectively, which were similar to the observations recorded in the positive control rabbits. However, the clinical score for negative control rabbits did not increase significantly (P > 0.05) during the experiment, and this changed from 3.32 to 3.37 in the ears, and there were no significant differences in clinical efficacy between left and right ears. After two treatments (0 and 7 d), the rabbits in groups A, B, C and D had recovered completely 14 days after the last treatment and no recurrences of infection were observed. These results indicate that euptox A was potent compounds for the effective control of animal P. cuniculi in vivo.

Parasitological study of scabies, in sheep and human

Objective: 1- Isolation and diagnosis of mites species in sheep. 2-To study the pathological changes in the skin. 3-To know the epidemiological distribution of Scabies in human. Materials and Methods: Scrabing was collected from infected area of skin of sheep and human. These specimens were treated with 10% KOH to remove scales and hairs, and then fixed on slides for diagnosis. Biopsies were taken from infected skin for pathological study. Results: Three species of mites were diagnosed on sheep, Sarcoptes scabiei, Psoroptes ovis and Chorioptes sarcoptes, with percents of infection 34.95%, 58.27%, 4.71% respectively. Gross pathological changes observed were, toughness, dryness, fissuring of the skin with white scales, while microscopical pathological changes revealed, hyperkeratosis, acanthosis, infiltration of chronic inflammatory cells (eosinophils, macrophages and lymphocytes) and oedema in the dermis. Age group of 11-30 years of age were highly affected (28.2%). Housewives were the highest percent among other occupation (29.1%). Conclusions: Scabies is a big public health problem and should be looked after among sheep as well as human beings.

Hormonal and behavioral changes induced by acute and chronic experimental infestation with Psoroptes cuniculi in the domestic rabbit Oryctolagus cuniculus

BackgroundParasitic diseases are important in animal production because they cause high economic losses. Affected animals often exhibit stereotypical behavioral alterations such as anorexia and inactivity, among others. Among the diseases that commonly affect domestic rabbits is mange, which is caused by the mite Psoroptes cuniculi. Therefore, within the context of the host-parasite relationship, it is critical to understand the mechanisms involved in the alteration of host behavior, in order to better utilize sick animal behavior as a strategy for diagnosis and treatment of disease.MethodsRabbits were infested placing mites in the ear conduct. We characterized changes in exploratory behavior and scent marking evoked by acute (1-9 days) and chronic (25-33 days) experimental infestation. Behavior was recorded during ten minutes while the animals were in a 120 cm × 120 cm open field arena divided into 9 squares. Serum cortisol was measured individually using radioimmunoassay kits. Locomotor activity, chinning, rearing and body weight were compared using a Friedman test, the effect of treatment (infested versus non-infested) across time was analyzed using a repeated measures ANOVA, and the Pearson test was used to determine whether chinning and ambulation scores were significantly correlated. Serum cortisol levels and food consumption were analyzed with a Kruskal-Wallis test and body temperature was analyzed with an ANOVA test.ResultsWe observed a significant decrease in rearing behavior as early as two days post-infestation, while chinning and locomotor activity were significantly decreased four days post-infestation. Chronic infestation was associated with decreased food intake, significant weight loss, and a trend toward increased serum cortisol levels, while no changes were observed in body temperature.ConclusionsThe presence of visible lesions within the ear canal is commonly used to detect mite infestation in rabbits, but this is possible only after chronic infestation. The behaviors described here may be a useful and economic tool in guiding the early diagnosis of parasitic infestation by P. cuniculi, allowing for early treatment and the application of control measures before significant weight loss occurs, thereby avoiding economic losses.

A Case of Atypical Psoroptic Mange in a Domestic Rabbit

A female checkered giant cross rabbit (Oryctolagus cuniculus) was presented with skin lesions on the perineal region. The cutaneous lesions extended 2cm from the vulva and perineal glands. They were moist and erythematous, with abundant greasy yellowish scabs. Skin scrapings from the lesions were mounted in Amman’s chloral-lactophenol on microscope slides and examined at ×10 and ×40 magnification. Numerous mites were observed and identified as Psoroptes cuniculi, a common causal agent of otitis externa in rabbits. The rabbit was treated successfully with ivermectin. This case of psoroptic mange is atypical owing to the perineal location, apparent absence of auricular lesions, and the lack of contagion despite close contact with several other rabbits.

Acaricidal properties of an Ailanthus altissima bark extract against Psoroptes cuniculi and Sarcoptes scabiei var. cuniculi in vitro

The potential acaricidal properties of an Ailanthus altissima bark extract were assessed against two common species of animal ectoparasitic mites, Psoroptes cuniculi and Sarcoptes scabiei var. cuniculi, in vitro. A. altissima bark extract was obtained by ethanol thermal circumfluence and tested at four concentrations (1.0, 0.5, 0.25 and 0.125 g/ml) on mites collected from rabbits. Compared to the fenvalerate treatment group, the A. altissima bark exhibited significant acaricidal properties for both mite species treated. The extract of concentrations of 1.0, 0.5 and 0.25 g/ml killed all tested S. scabiei within 7 h, however, only 1.0 and 0.5 g/ml of extract killed all treated P. cuniculi. The median lethal time (LT50) values at 1, 0.5 and 0.25 g/ml were 0.60, 0.78, 1.48 h for S. scabiei and 0.74, 1.29, 3.33 h for P. cuniculi. The median lethal concentration (LC50) for P. cuniculi was approximately 1.6 times that for S. scabiei var. cuniculi at 4 h. The extract showed stronger toxicity against S. scabiei than against P. cuniculi. Mortality rates increased with increasing concentration of extract administered and with increasing time post-treatment, indicating that the acaricidal activity of A. altissima bark extract is both time-dependent and dose-dependent. This is the first report on acaricidal activity of A. altissima against P. cuniculi and S. scabiei var. cuniculi. It indicates that A. altissima contain potential acaricidal compounds. Our study is the first step to develop potentially novel compounds from A. altissima for the effective control of mites in livestock.

Efficacy of the d-phenothrin/pyriproxyfen association against mites in naturally co-infested rabbits

The aim of the present study was to evaluate the efficacy of the d-phenothrin/pyriproxyfen association against Psoroptes ovis, Cheyletiella parasitivorax, and Leporacarus gibbus infestations in naturally co-infested rabbits. Twenty crossbreed (New Zealand White x California) rabbits concurrently infested by the three mite species were randomly divided in two groups. All rabbits presented with hyperemia, erythema and formation of crusts in the ear canals caused by P. ovis. Infestations by both C. parasitivorax and L. gibbus were considered asymptomatic in all animals.Ten animals were treated with a 4.4% d-phenothrin and 0.148% pyriproxyfen spray formulation until have their body surface uniformly sprayed, including external ear canals. The other ten rabbits remained untreated, serving as control group. Observations were done on days +7, +14, +21, +28, and +35 post-treatment. The d-phenothrin/pyriproxyfen association showed 100% efficacy against the three mite species and was responsible for the remission of psoroptic mange lesions on treated animals. No signs of intoxication were observed. The results indicate that d-phenothrin/pyriproxyfen spray formulation in a single application is an effective and clinically safe option for the control of different mite infestations in rabbits.

Characterization of the ovine complement 4 binding protein-beta (C4BPB) chain as a serum biomarker for enhanced diagnosis of sheep scab

Sheep scab, caused by the highly contagious mite Psoroptes ovis, is endemic in a number of sheep-producing countries worldwide, and is a major animal welfare and economic concern. Recent developments in the diagnosis of sheep scab include a highly sensitive and specific serum antibody-based assay which can be used to indicate exposure to the parasite but not necessarily current disease status. Here, a transcriptomic and bioinformatics analysis of the circulating leukocytes of sheep with active P. ovis infestation indicated that the transcription levels of complement 4 binding protein beta (C4BPB) increased by 12 fold from pre-infestation to 6 weeks post-infestation. Semi-quantitative studies confirmed increased serum C4BPB protein levels in sheep infested with P. ovis. To quantify this serum protein response and characterize ovine C4BPB as a biomarker for active P. ovis infestation, the ovine C4BPB gene was sequenced, a recombinant protein expressed, antibodies against this protein were raised in rabbits and a sandwich ELISA developed. The results from this assay indicated that serum C4BPB protein levels increased 4-fold from pre-infestation to 6 weeks post-infestation, which demonstrated the potential of the assay to quantify C4BPB in sheep sera and indicated the potential of C4BPB as a biomarker of current disease status in sheep post-infestation and post-treatment.

The effect of Psoroptes ovis infestation on ovine epidermal barrier function

Sheep scab is an intensively pruritic, exudative and allergic dermatitis of sheep caused by the ectoparasitic mite Psoroptes ovis. The purpose of the present study was to investigate the effect of P. ovis infestation on different components of the ovine epidermal barrier within the first 24 hours post-infestation (hpi). To achieve this, the expression of epidermal differentiation complex (EDC) genes and epidermal barrier proteins, the nature and severity of epidermal pathology and transepidermal water loss (TEWL) were evaluated.By 1 hpi a significant dermal polymorphonuclear infiltrate and a significant increase in TEWL with maximal mean TEWL (598.67 g/m2h) were observed. Epidermal pathology involving intra-epidermal pustulation, loss of epidermal architecture and damage to the basement membrane was seen by 3 hpi. Filaggrin and loricrin protein levels in the stratum corneum declined significantly in the first 24 hpi and qPCR validation confirmed the decrease in expression of the key EDC genes involucrin, filaggrin and loricrin observed by microarray analysis, with 5.8-fold, 4.5-fold and 80-fold decreases, respectively by 24 hpi.The present study has demonstrated that early P. ovis infestation disrupts the ovine epidermal barrier causing significant alterations in the expression of critical barrier components, epidermal pathology, and TEWL. Many of these features have also been documented in human and canine atopic dermatitis suggesting that sheep scab may provide a model for the elucidation of events occurring in the early phases of atopic sensitisation.

Farmer perceptions of the prevalence and management of Psoroptes ovis infestation in sheep flocks in southwest England

Psoroptic mange (scab) is a problem of significant concern for sheep welfare. Many aspects of the epidemiology of the disease contribute to difficulties in diagnosis and the prevention of transmission...