Cellular response in the dermis of common wombats (Vombatus ursinus) infected with Sarcoptes scabiei var. wombati

The cellular response in the dermis of common wombats (Vombatus ursinus) with sarcoptic mange exhibited some typical aspects of an immune response to Sarcoptes scabiei. There was an induction phase for wombats experimentally infected with S. scabiei represented by absence of a dermal inflammatory infiltrate for at least 12 days after infection. T lymphocytes, plasma cells, mast cells, and neutrophils then entered the dermis, consistent with a type IV (delayed) hypersensitivity response. In free-living wombats with severe parakeratotic sarcoptic mange eosinophils were also present in the dermis suggesting that a type I (immediate) hypersensitivity response may develop after a type IV hypersensitivity response. Absence of plasma cells and B lymphocytes in free-living wombats with severe parakeratotic sarcoptic mange compared with their presence in wombats experimentally infected with S. scabiei suggested that some immune tolerance may develop with severe infections. A large proportion of cells in the dermal response were not identified but were possibly cells of connective tissue. The thickness of the epidermis increased within 4 days in response to S. scabiei infection. Some antibodies raised against human leucocyte antigens CD3, CD5, HLA-DP, DQ, DR, and CD79b cross-reacted with leucocyte antigens of common wombats and were used to identify cell types in inflammatory infiltrates using immunohistochemistry.     

Sarcoptes mange (Sarcoptes scabiei) increases diurnal activity of bare-nosed wombats (Vombatus ursinus) in an agricultural riparian environment

Sarcoptes mange is an important disease that affects the health, mobility and longevity of bare-nosed wombats (Vombatus ursinus) in Australia. We measured the activity patterns of wombats infected with varying levels of mange in an agricultural riparian environment using motion-sensing cameras. Over a 10 month period we observed a greater increase in nocturnal activity of mange-free wombats than those with mange on six or more body sections. The percentage of mange-infected wombats was greater during the day, but in the 6 h after midnight, wombats were detected with fewer mange-infected segments. Air temperature at the time of wombat detections was generally higher for individuals with mange than those without mange. Our results show that diurnal activity of wombats is likely to increase with higher levels of infection by sarcoptes mange. Increased diurnal activity is likely to present serious problems for the persistence of sustainable populations of wild wombats.     

Experimental infections of brush-tailed possums, common wombats and water rats with Leptospira interrogans serovars balcanica and hardjo

Of 12 brush-tailed possums (Trichosurus vulpecula) inoculated with Leptospira interrogans serovar balcanica 11 developed migroagglutination (MA) antibody to jardjo antigen by 14 days postincubation (PI). Leptospiruria was observed in 2 possums 117 to 145 days PI. Of 6 possums inoculated with serovar hardjo 4 developed low short-lived titres by day 18 PI. Two of 3 wombats (Vombatus ursinus) inoculated with balcanica had high MA titres (greater than or equal to 1:128) by day 16 PI and leptospiruria occurred by day 16. One wombat inoculated with hardjo developed a low MA titre. Low transitory MA titres to hardjo were found in 1 of 3 water rats (Hydromys chrysogaster) after inoculation with balcanica and 1 of 2 given hardjo. Histopathological examination of kidneys revealed mild to moderately severe focal interstitial nephritis in 4 of 8 possums, in 2 wombats and in 2 water rats following experimental infection with balcanica. Similar lesions were observed in 2 of 4 possums, 1 wombat and 2 water rats following experimental infection with hardjo.     

Can androgen deficiency promote an outbreak of psoroptic mange mites in male deer?

Repeated outbreaks of infection by psoroptic mange mites (Psoroptes equi var. ovis) affecting most regions of the body and legs were observed in several male white-tailed deer (Odocoileus virginianus) suffering from hypoandrogenism (e.g., castrates, animals treated with antiandrogens or postprime). The massive infection was characterized by a severe alopecia and skin inflammation and began usually in early winter. One or two spray treatments of a 1% solution of Lindane was usually sufficient to eliminate the clinical signs of the disease and to restore a healthy hair coat. Neither healthy male or female deer have ever exhibited any external signs of this disease nor has the parasite been detected in the scrapings of their skin. We propose a possible relationship between the hormonal status of these animals and their resistance to this parasitic mite infection.     

Distribution of life cycle stages of Sarcoptes scabiei var wombati and effects of severe mange on common wombats in Victoria

Seven female and three male common wombats (Vombatus ursinus) collected from forested areas of Victoria (Australia) over a 10 mo period, 10 April 1997 to 22 February 1998 had at least 30% of their skin affected by severe hyperkeratotic sarcoptic mange. Mangy wombats were grazing during the day, could be readily approached, were in poor body condition, and lacked subcutaneous fat. The anterolateral surface of the body was most heavily parasitised with Sarcoptes scabiei var wombati followed by the posterolateral surface, the dorsal region between the ears, the ears, ventral abdomen, medial aspect of the legs, axillary and inguinal areas, and the dorsal midline. Larvae were the most prevalent life-cycle stage followed by eggs, nymphs, females, and males. Mite numbers and the severity of clinical signs, namely thickness of scale crust and the degree of alopecia, were correlated and were symmetrical on each side of the body. Fissuring of crust and skin only occurred when scale crust was present. Bacterial infections occurred in three of 10 wombats within lymph nodes or the pleural cavity. Lymphoid depletion did not occur in lymph nodes or spleens and prescapular lymph nodes contained a greater amount of nuclear debris in germinal centres than non-mangy wombats. Seven wombats had fatty change in their livers. Gonads of mature wombats were not active or had minimal activity. Significant histopathological changes were not seen in the gastrointestinal tract, kidney, brain, myocardium, spleen, thyroid, reproductive tract, and gonads. Hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, and concentrations of hemoglobin, lymphocytes, calcium, glucose, creatinine, total solids, total protein, albumin determined both colormetrically and electrophoretically, and globulins were significantly lower and concentrations of neutrophils, monocytes, phosphorus, urea, glutamate dehydrogenase, aspartate aminotransferase and creatine kinase were significantly higher in mangy versus captive wombats. Concentrations of erythrocytes, mean corpuscular hemoglobin, leucocytes, band neutrophils, eosinophils, nucleated erythrocytes, sodium, potassium, chloride, total bilirubin, alkaline phosphatase, and gamma glutamyltransferase for mangy wombats were not significantly different from that reported for captive wombats. Hematological and pathological changes in mangy wombats were consistent with anemia, inflammation, and changes seen with starvation.     

Resistance to reinfection in chinook salmon Oncorhynchus tshawytscha to Loma salmonae (Microsporidia).

Chinook salmon Oncorhynchus tshawytscha were experimentally infected per os with Loma salmonae and held in flow-through seawater tanks at 12 to 14 degrees C. The fish exhibited 100% infection when first examined at 7 wk post initial exposure (p.e.), and by 20 wk p.e. they had completely recovered from gill infections. The recovered fish were then re-exposed the following week. All of these fish showed strong protection to new L. salmonae infections, while na?ve fish exposed to the same inoculum developed the infection. Most of the re-exposed fish exhibited a few free spores or spores within phagocytes in the kidney interstitium at 20 to 29 wk p.e., but xenomas were not detected in either the gills or visceral organs. The kidney is the primary site of reticulo-endothelial activity, and thus these spores were likely deposited in the kidney by entrapment by fixed macrophages. It is possible that these spores provide immunologic stimuli to reinforce the resistance to new L. salmonae infections.     

Sarcoptes scabiei: The Mange Mite with Mighty Effects on the Common Wombat (Vombatus ursinus)

Parasitism has both direct and indirect effects on hosts. Indirect effects (such as behavioural changes) may be common, although are often poorly described. This study examined sarcoptic mange (caused by the mite Sarcoptes scabiei) in the common wombat (Vombatus ursinus), a species that shows severe symptoms of infection and often causes mortality. Wombats showed alterations to above ground behaviours associated with mange. Infected wombats were shown to be active outside of the burrow for longer than healthy individuals. Additionally, they spent more time scratching and drinking, and less time walking as a proportion of time spent above ground when compared with healthy individuals. They did not spend a higher proportion of time feeding, but did have a slower feeding rate and were in poorer body condition. Thermal images showed that wombats with mange lost considerably more heat to the environment due to a diminished insulation layer. Infection status did not have an effect on burrow emergence time, although this was strongly dependent on maximum daily temperature. This study, through the most detailed behavioural observations of wombats to date, contributes to a broader understanding of how mange affects wombat health and abundance, and also to our understanding of the evolution of host responses to this parasite. Despite being globally dispersed and impacting over 100 species with diverse intrinsic host traits, the effects of mange on hosts are relatively poorly understood, and it is possible that similar effects of this disease are conserved in other host species. The indirect effects that we observed may extend to other pathogen types.     

Notoedric mange in two free-ranging mountain lions (Puma concolor)

Two mountain lions (Puma con-color) were found dead in the Simi Hills area of southern California (Ventura County). Postmortem examination and toxicological analyses indicated that the cause of death was anticoagulant rodenticide intoxication. In addition, both lions had marked alopecia and skin crusts, caused by Notoedres cati. The diagnosis of notoedric mange was confirmed by histology and direct examination of mites obtained from skin scrapings of the two animals. Histologically, the affected skin showed acanthotic epidermis with parakeratosis and parasitic tunnels in the stratum corneum. This is the first report of the pathological changes associated with notoedric mange in free-ranging mountain lions.     

Clinical Picture and Antibody Response to Experimental Sarcoptes scabiei var. vulpes Infection in Red Foxes (Vulpes vulpes)

Three red foxes (Vulpes vulpes) were experimentally infected with Sarcoptes scabiei isolated from a naturally infected wild red fox. A fourth red fox served as a control. The first signs of sarcoptic mange became evident on the 31st day post infection (dpi). The signs gradually increased thereafter and between dpi 49 and 77 characteristic lesions of hyperkeratosis developed. Two of the infected foxes developed severe sarcoptic mange, and one of these animals died on dpi 121. The third fox developed a chronic hyperkeratotic lesion on its back, at the site where the mites had been applied. On dpi 127 the surviving foxes were treated systemically with ivermectin, and within 4 weeks the skin lesions had healed except on the pinnae of one animal. Antibodies to S. scabiei var. vulpes were demonstrated in the infected foxes by an ELISA with which seroconversion was seen around 4 weeks post infection (wpi). Western blot analysis of sequential sera of the infected animals demonstrated antibody activity consistently after the 2nd wpi. The fourth, non-infected, fox did not show any skin lesions throughout the experimental period nor any specific antibodies to S. scabiei var. vulpes. kw|Keywords|k]sarcoptic mange; k]red fox; k]serodiagnosis; k]ELISA     

Neospora caninum (Protozoa: apicomplexa) infections in mice

Groups of mice were given 0 mg, 4 mg, or 2 mg of methylprednisolone acetate (MPA) 7 days prior to, the day of, and 7 days after subcutaneous inoculation with 0 or 2 x 10(5) tachyzoites of Neospora caninum. Clinical signs of disease were seen only in mice given both MPA and N. caninum tachyzoites. Mice given 4 mg MPA and N. caninum tachyzoites developed severe disseminated neosporosis and most died or were killed when comatose 11-13 days postinoculation (PI). Acute pneumonia, polymyositis, encephalitis, hepatitis, and pancreatitis were the main lesions in these mice. Mice given 2 mg MPA and N. caninum developed mild pneumonia and many mice began showing neurological signs 14 days PI. Neurological signs consisted mainly of pronounced head-tilting and associated impairment of movement. Grossly visible 1-2-mm single or multiple, white areas of discoloration were seen in the brains of many of these mice. Encephalitis, ganglioradiculoneuritis, pneumonia, and polymyositis were the main changes seen in these mice. Tissue cysts of N. caninum were only seen in mice given 2 mg MPA and were first seen 21 days PI. Tissue cysts were 16-34 by 13-29 microns and had a 1.5-3.0-microns-thick cyst wall. Tissue cysts were seen only in the brain. Mice given 4 mg MPA and tachyzoites and host cells that had been frozen for 1 wk did not develop clinical signs of infection, indicating that freezing kills tachyzoites and that viruses or other agents were not involved in the genesis of disease seen in mice given MPA and viable tachyzoites.(ABSTRACT TRUNCATED AT 250 WORDS)     

Sarcoptes scabei var. wombati infection in the common wombat (Vombatus ursinus)

Sarcoptic mange has been identified as the most significant infectious disease affecting the common wombat (Vombatus ursinus). Biochemistry and haematology values for wild common wombats have not been published previously. A 35% of the wombat population were exhibiting clinical signs of the disease. Significant changes in blood haematology and biochemistry parameters were observed in affected animals. A seasonal variation in numbers of animals affected was demonstrated. Females appeared to be more commonly affected than males although the reason for this is not forthcoming.     

Invading parasites cause a structural shift in red fox dynamics

The influence of parasites on host life histories and populations is pronounced. Among several diseases affecting animal populations throughout the world, sarcoptic mange has influenced many carnivore populations dramatically and during the latest epizootic in Fennoscandia reduced the abundance of red fox by over 70%. While the numerical responses of red fox populations, their prey and their competitors as well as clinical implications are well known, knowledge of how sarcoptic mange affects the structure of the dynamics of red fox populations is lacking. Integrating ecological theory and statistical modelling, we analysed the long-term dynamics (1955-1996) of 14 Danish red fox populations. As suggested by the model, invading sarcoptic mange significantly affected direct and delayed density dependence in red fox dynamics and concomitant shifts in fluctuation patterns were observed. Our statistical analyses also revealed that the spatial progressive spread of mange mites was mirrored in the autocovariate structures of red fox populations progressively exposed to sarcoptic mange.     

Notoedric mange in western gray squirrels from Washington

From February 1998 to July 1999, 65 western gray squirrels (Sciurus griseus griseus) were trapped at three sites in Klickitat County, Washington (USA) as part of a home range and habitat use study. No squirrels (0/9) with mange lesions were identified in the initial trapping session (February and March 1998). During all subsequent trapping sessions (August 1998 through July 1999), squirrels with lesions consistent with notoedric mange, caused by the mite Notoedres centrifera (douglasi), were captured or recaptured at all three study sites. The diagnosis was confirmed by histopathology and examination of mites obtained from skin scrapings from two affected squirrels. Of the 56 squirrels captured from August 1998 to July 1999, 33 (59%) had characteristic mange lesions, and 14 (42%) affected squirrels died directly of mange or of secondary complications of mange. Only four breeding females of 22 radio-collared animals (males and females) in the study population were known to have survived the mange outbreak (12 died, 6 missing). Factors potentially contributing to this mange outbreak include a mast crop failure in the fall of 1998 and transmission of mites from animial to animal during trapping and processing sessions.     

The First Outbreak of Chorioptes texanus (Acari: Psoroptidae) Infestation in a Cattle Farm in Korea

Mites in the genus Chorioptes cause a mild form of skin disease in both domestic and wild ruminants. In July 2006, dermatitis characterized by alopecia, marked lichenification, accumulation of crust, and fissuring was recognized in 14 out of 200 Holstein dairy cattle raised in the cattle farm of the National Institute of Animal Science in Cheonan, Republic of Korea. Skin lesions were distributed mainly over the tail base, and sacral and perineal regions. Microscopic examinations of skin scraping samples from severely affected areas revealed numerous mites of all developmental stages. Morphologically, pedicels of the mites were short and unjointed. The tarsal suckers occurred on the pedicels of all the legs in the male worm and on the first, second, and fourth pair of legs in the adult female worm. A single long seta at the tarsus of legs III and the length of legs II being about twice as long as legs IV in adult male mites were observed. Arising anterior to the inner-most spatulate seta was a short seta with an average of 26.4 ± 5.8 µm in length. Also, the length of setae #4 on the opisthosomal lobes was relatively short. Based on these observations, the mites were identified as Choriptes texanus. Although the chorioptic mange may not influence the mortality rate in the affected farm, reports indicate that a decline in milk production can be observed. This is the first report of chorioptic infestation in a cattle farm from Korea.     

Brief perinatal hypoxia increases severity of pulmonary hypertension after reexposure to hypoxia in infant rats

We hypothesized that disrupted alveolarization and lung vascular growth caused by brief perinatal hypoxia would predispose infant rats to higher risk for developing pulmonary hypertension when reexposed to hypoxia. Pregnant rats were exposed to 11% inspired oxygen fraction (barometric pressure, 410 mmHg; inspired oxygen pressure, 76 mmHg) for 3 days before birth and were maintained in hypoxia for 3 days after birth. Control rats were born and raised in room air. At 2 wk of age, rats from both groups were exposed to hypoxia for 1 wk or kept in room air. We found that brief perinatal hypoxia resulted in a greater increase in right ventricular systolic pressure and higher ratio of right ventricle to left ventricle plus septum weights after reexposure to hypoxia after 2 wk of age. Moreover, perinatal hypoxic rats had decreased radial alveolar counts and reduced pulmonary artery density. We conclude that brief perinatal hypoxia increases the severity of pulmonary hypertension when rats are reexposed to hypoxia. We speculate that disrupted alveolarization and lung vascular growth following brief perinatal hypoxia may increase the risk for severe pulmonary hypertension with exposure to adverse stimuli later in life.     

Immunization with a live, attenuated simian immunodeficiency virus (SIV) prevents early disease but not infection in rhesus macaques challenged with pathogenic SIV.

An infectious, virulence-attenuated molecular clone of simian immunodeficiency virus (SIV), SIVMAC-1A11, was derived from an SIV isolate that causes fatal immunodeficiency in rhesus macaques. When inoculated intravenously in rhesus macaques, SIVMAC-1A11 induced transient viremia (1 to 6 weeks) without clinical disease and a persistent humoral antibody response. The antibodies were directed mainly against the viral envelope glycoproteins, as determined by immunoblots and virus neutralization. The potential of this virulence-attenuated virus to protect against intravenous challenge with a pathogenic SIVMAC strain was assessed. Five rhesus macaques were each given two intravenous inoculations with SIVMAC-1A11 7 months apart. Three of the five immunized monkeys and four naive control animals were then challenged with 100 to 1,000 100% animal infectious doses of pathogenic SIVMAC. All seven animals became persistently viremic following the challenge. Four of four unimmunized animals developed severe clinical signs of simian acquired immunodeficiency syndrome by 38 to 227 days after challenge and were euthanatized 91 to 260 days postchallenge. However, no signs of illness were seen in immunized monkeys until 267 to 304 days postchallenge, when two of three immunized animals developed mild thrombocytopenia and lymphopenia; one of these animals died with clinical signs of simian immunodeficiency disease at 445 days after challenge. The two SIVMAC-1A11-immunized monkeys that were not challenged were healthy and antibody positive 22 months after the initial immunization. Thus, although live SIVMAC-1A11 was immunogenic and did not induce any disease, it failed to protect rhesus macaques against infection with a moderately high dose of pathogenic virus. However, immunization prevented severe, early disease and prolonged the lives of monkeys subsequently infected with pathogenic SIV.     

Prevalence and risk factors assessment of mange mites in livestock of Malakand Division,Pakistan

Mange mites represent a serious problem in livestock farming due to their worse effect on animals health, reducing milk and meat production. The status of mange mites prevalence was unknown from the livestock present in Malakand Division, Pakistan. Hence, the present study was conducted to determine the prevalence and risk factors assessment of mange mites in livestock of Malakand Division, Pakistan. Villages and livestock herds were visited for data collection and sampling for one year from September 2017 to August 2018. The diagnosis of mange infestation was carried out from skin scrapings collected from symptomatic animals. A total of 1437 animals were screened (240 sheep, 658 cows, 340 buffalos, 199 goats) from selected localities of the Malakand Division. The overall prevalence was 2.37%, with the highest prevalence in buffalos (5.0%) and lowest (0.42%) in sheep (p < 0.05). The locality also significantly affect the prevalence of mange mites in livestock, with a higher percentage (8.14%) in the Ouch area. The prevalence was higher in winter (3.78%) than in summer (1.07%). The prevalence was high (p < 0.05) in young animals (≤1 year) (4.7%) as compared to adults (>1 year) (1.15%). Gender was also a significant risk factor for mange infestation. The infestation was higher in females (2.85%) as compared to males (0.64%) (p < 0.05). Herd size of less than ten animals had a significantly high prevalence rate (3.69%) compared to >10 animals (1.89%). Animals having an infection history >15 days infected more than animals having infection history ≤15 days. This study documented for the first-time epidemiology of mange mites in livestock of Malakand Division, Pakistan. Further studies involving molecular characterization of mange mites will increase our understanding on the spread of mange mites in Malakand Division livestock.     

Secondhand smoke induces allergic sensitization in mice

Epidemiological studies have suggested increased prevalence of atopy in children of maternal smokers. Although secondhand smoke or environmental tobacco smoke (ETS) has been shown to augment allergic responses, its role in atopic sensitization is still controversial. We studied whether ETS could initiate a Th2 response and thus induce primary allergic sensitization. Mice were exposed for 10 consecutive days to either 1% aerosolized OVA, ETS (5 cigarettes), or both ETS and OVA. C57BL/6 mice receiving both ETS and OVA developed OVA-specific IgE and IgG1, 12, 14, and 25 days after the initial exposure, whereas those receiving OVA alone did not. Thirty days after the initial challenge (20 days after its completion), mice were re-exposed to OVA. Bronchoalveolar lavage performed 24 h later revealed an influx of eosinophils in the group initially challenged with both ETS and OVA, but not in those exposed to ETS alone or OVA alone. Increases in IL-5, GM-CSF, and IL-2 were observed in bronchoalveolar lavage from this OVA/ETS-exposed group, whereas IFN-gamma levels were significantly inhibited. These results suggest that ETS can induce allergic sensitization to a normally harmless Ag, and they may explain why secondhand smoke is a major risk factor for the development of allergy in children.     

Infection of Psoroptes mites with the fungus Metarhizium anisopliae

The astigmatid mite, Psoroptes ovis (Hering) (Acari: Psoroptidae), is an obligatory ectoparasite that causes psoroptic mange in a range of domesticated animals, particularly sheep, where the clinical disease is known as sheep scab. A series of laboratory assays were used to assess the use of the fungus, Metarhizium anisopliae (Metchnikoff) (Deuteromycotina: Hyphomycetes) as a biocontrol agent for P. ovis derived from rabbits (syn. P. cuniculi). The immersion of mites in a suspension of conidia of M. anisopliae resulted in the acquisition of fatal infections. The number of mites which developed infections increased significantly with the increasing concentration of the conidial suspension to which they were exposed; 77% of mites developed infections when exposed to the highest concentration used (1 x 10(8) conidia ml(-1)). Controls developed no fungal infections. Mites allowed simply to walk across a surface which had been treated with a suspension of conidia also acquired fungal infections; the number infected was again related to the concentration of conidia present. After contact for 24 h with a surface treated with 1 x 10(8) conidia ml(-1), 73% of the mites became infected. To determine whether dead infected mites could act as sources of infection, infected cadavers were placed in chambers with live uninfected mites. The uninfected mites acquired fatal infections from the cadavers; a higher ratio of infected cadavers to uninfected mites resulted in greater transmission of infection. The time after death of the infected cadaver was also an important factor influencing the number infected, 5-day-old cadavers were the most infective and 18-day-old cadavers the least infective. The results indicate that M. anisopliae is a good candidate control agent for Psoroptes mites.     

Response of rainbow trout Oncorhynchus mykiss to exposure to Myxobolus cerebralis above and below a point source of infectivity in the upper Colorado River

We exposed 9 wk old rainbow trout Oncorhynchus mykiss to ambient levels of Myxobolus cerebralis infectious stages at 4 sites of suspected differing infectivity in the Colorado River. Exposure was estimated by periodic filtration of river water at each exposure location. After a 32 d exposure, the fish were held in the Colorado River at a common site for over a year. Resulting infection was evaluated by the presence of clinical signs (whirling behavior, cranial deformity/exophthalmia, and black tail), severity of microscopic lesions, and myxospore counts (8, 10, 12, and 14 mo post-exposure). Two exposure sites that were immediately downstream of Windy Gap Reservoir were much higher in infectivity than the site above the reservoir or the site 26 km downstream of the reservoir. Rainbow trout exposed at those locations showed higher prevalence of clinical signs of whirling disease, more severe histological evidence of infection and higher average myxospore concentrations than those exposed above the reservoir or 26 km below the reservoir. Many more M. cerebralis actinospores were observed from water filtration at the 2 sites immediately below the reservoir compared to the other sites.