Hair-loss epizootic in moose (Alces alces) associated with massive deer ked (Lipoptena cervi) infestation

Deer keds (Lipoptena cervi) are blood-sucking flies in the family Hippoboscidae; moose (Alces alces) are their main host in Scandinavia. There are no detailed reports of the negative impacts of deer keds on moose. In 2006 and 2007, hunters in southeastern Norway and midwestern Sweden found several moose cadavers with severe alopecia; numerous moose had extensive hair loss. Between February 2006 and June 2007, materials from 23 moose were submitted for laboratory examination and large numbers of deer keds were found in the coat of most animals. The body condition of the moose varied but was poor in animals with severe alopecia. The findings of enormous numbers of deer keds in the coat of the majority of the affected animals and a consistent histologic image (acute to chronic, multifocal to coalescing, eosinophilic to lymphocytic dermatitis), concurrent with the absence of any other lesions, trace element deficiencies, or dermal infections which are known to cause alopecia, suggest that the hair-loss epizootic was linked to massive infestations with deer keds. The emergence of this hair-loss syndrome implies that the dynamics between parasite and host have been disrupted by a currently unknown environmental or ecological factor. A high moose density, combined with extraordinarily mild weather June 2006-June 2007 and a particularly long period with the absence of night-frost in autumn of 2006, may have been ideal for deer ked development, survival, and optimal host acquisition.     

Morphological variation between populations of the expanding ectoparasitic deer ked Lipoptena cervi (Diptera: Hippoboscidae) in Fennoscandia

We examined morphological and genetic differences among Fennoscandian deer ked (Lipoptena cervi L, Hippoboscidae) populations with varying expansion history: the eastern population (Finland) has expanded rapidly, whereas the western population is divided into an old and relatively stationary sub‐population in Sweden and a newly established and more expansive sub‐population in Norway. The genetic analysis suggests that the distinct populations represent a single species. Individuals from expansive populations were characterized by a large body size, relatively large and robust thorax shape, and wing shape with an exaggerated basal posterior margin. Yet, there was no among population variation in relative wing size or its elongated shape after variation in overall size was controlled for. Although certain size and shape variables showed thermal sensitivity, the degree of plasticity did not differ between the populations. In general, we observed that shape is more sensitive to external thermal conditions at the pupal stage than size per se, with the thermal sensitivity of the latter depending on the trait under examination. We conclude that the possible adaptive value of morphological differences relies on variation in survival during the off‐host life stages or short‐distance flight to reach a susceptible host instead of long‐distance dispersal ability.     

Salt licks do not increase local densities of the deer ked,Lipoptena cervi,an abundant ectoparasite of cervids

The deer ked, Lipoptena cervi (Diptera: Hippoboscidae), is a common ectoparasite of the moose, Alces alces (Artiodactyla: Cervidae). Salt licks are widely used to manipulate moose movements to prevent damage to saplings and traffic accidents. They may cause moose to gather in small areas, which could create aggregates of deer ked pupae as the parasite is a short‐distance flyer and its dispersion depends on its hosts. We investigated whether the population density of flying deer keds could be influenced by manipulating salt licks and how environmental variables affect parasite density. Densities were estimated in 40 experimental sites with four treatments (no salt licks, introduced salt licks, removed salt licks, permanent salt licks) in September during 2007–2010. Forest edges, mixed forests on mineral soil and coniferous forests on peat soil were the habitats with high numbers of parasites. The manipulation of salt licks seemed to be ineffective in reducing the density of deer keds as the only factor to show statistical significance with parasite numbers in the mixed‐model analysis was year of determination. Annual deer ked densities correlated with the abundance of moose in the region. Moreover, high spring and summer temperatures seemed to increase the numbers of flying imagos.     

Parasitism of the deer ked,Lipoptena cervi,on the moose,Alces alces,in eastern Finland

The deer ked, Lipoptena cervi L. (Diptera: Hippoboscidae), is an ectoparasitic fly that spread to Finland in the early 1960s from the southeast across the Soviet border. It is currently a common parasite of the moose, Alces alces (Artiodactyla: Cervidae), in the southern part of the country and its area of distribution is gradually spreading to Finnish Lapland, where it will come into contact with another potential cervid host, the semi‐domesticated reindeer, Rangifer tarandus tarandus. The aim of this study was to determine the intensity of deer ked parasitism on the moose in eastern Finland. Whole skins of 23 moose were examined for the presence of deer keds, which were extracted and their total numbers estimated. The intensity of deer ked parasitism was correlated to the age, sex, skin area and anatomical region of the host. Bulls had the highest total number of keds (10616 ± 1375) and the highest deer ked density (35.7 ± 4.4 keds/dm² of skin). Cows had a higher total number of keds than calves (3549 ± 587 vs. 1730 ± 191), but ked densities on cows and calves were roughly equal (11.8 ± 1.7 vs. 9.4 ± 1.1 keds/dm² of skin). The density of keds was highest on the anterior back, followed by the posterior back, front limbs, abdomen, head and hind limbs. The sex ratio of deer keds was close to equal (male : female, 1.0 : 1.1). After they had consumed blood, male keds were heavier than females. As the total numbers and densities of deer keds were higher than reported previously on moose or for any other louse fly species, the effects of parasitism on the health of the host species should be determined.     

Predicting range expansion of an ectoparasite – the effect of spring and summer temperatures on deer ked Lipoptena cervi (Diptera: Hippoboscidae) performance along a latitudinal gradient

The range expansion of organisms towards higher latitudes and altitudes is often limited by colder temperatures and the shorter growth season. In parasites, survival outside the host is most likely to affect their potential establishment in novel environments. We conducted a large scale transplant experiment to predict the potential spread of the deer ked Lipoptena cervi (Diptera: Hippoboscidae), a blood‐feeding ectoparasite of boreal cervids. We studied the off‐host survival and pupal development of deer ked in five sites along a latitudinal gradient reaching from its current range in central Finland to northernmost Fennoscandia. We showed that the deer ked is able to survive and complete its development even in arctic environments, 500 km northwards beyond the current range. Performance deteriorated steadily towards north, where lower summer temperatures prolonged the developmental period and shortened the suitable host search time by several weeks. The relevance of the experiments for estimating the spread of deer ked to the north is discussed.     

Bartonella Infections in Deer Keds (Lipoptena cervi) and Moose (Alces alces) in Norway

Infections with Bartonella spp. have been recognized as emerging zoonotic diseases in humans. Large knowledge gaps exist, however, relating to reservoirs, vectors, and transmission of these bacteria. We describe identification by culture, PCR, and housekeeping gene sequencing of Bartonella spp. in fed, wingless deer keds (Lipoptena cervi), deer ked pupae, and blood samples collected from moose, Alces alces, sampled within the deer ked distribution range in Norway. Direct sequencing from moose blood sampled in a deer ked-free area also indicated Bartonella infection but at a much lower prevalence. The sequencing data suggested the presence of mixed infections involving two species of Bartonella within the deer ked range, while moose outside the range appeared to be infected with a single species. Bartonella were not detected or cultured from unfed winged deer keds. The results may indicate that long-term bacteremia in the moose represents a reservoir of infection and that L. cervi acts as a vector for the spread of infection of Bartonella spp. Further research is needed to evaluate the role of L. cervi in the transmission of Bartonella to animals and humans and the possible pathogenicity of these bacteria for humans and animals.     

Aspects of the life cycle and pathogenesis of Elaphostrongylus cervi in red deer (Cervus elaphus)

Aspects of the migratory life cycle and pathogenesis of Elaphostrongylus cervi were studied in red deer (Cervus elaphus) using 2 farmed calves experimentally infected with 450 third-stage larvae killed 40 and 45 days postinfection and using 3 wild calves and 3 wild yearlings with natural infections killed during autumn hunting. A full necropsy was carried out on the experimental calves, but only the head, eviscerated carcass, and lungs were examined from the naturally infected animals. Histological examination included extensive studies of the central nervous system (CNS), spinal nerve roots, and lungs. The experimental calves had prepatent infections, with many immature adult nematodes in the CNS, whereas the wild calves showed CNS lesions indicating a very recent E. cervi infection. The yearlings had patent infections, with many mature E. cervi in their skeletal muscles, reflecting acquisition of infection during the previous summer. Our findings showed that E. cervi develop to the adult stage in the CNS (subarachnoid spaces) and subsequently migrate into the skeletal muscles, where the mature nematodes live in reproductive pairs and groups. In the nervous system, the nematode caused encephalomyelitis, focal encephalomalacia and gliosis, meningitis, radiculitis, ganglionitis, and perineuritis.     

Distribution of low molecular weight carbohydrates in the subgenusCeratotropis of the genusVigna (Leguminosae)

The seeds of 9 members of the subgenusCeratotropis (Piper) Verdc., namelyVigna aconitifolia (Jacq.) Maréchal,V. angularis (Willd.) Ohwi et Ohashi,V. minima (Roxb.) Ohwi et Ohashi,V. nakashimae (Ohwi) Ohwi et Ohashi,V. reflexo-pilosa Hayata,V. umbellata (Thumb.) Ohwi et Ohashi,V. mungo (L.) Hepper,V. radiata (L.) Wilczek andV. sp., have been examined. On their low molecular weight carbohydrate compositions, this subgenus has been divided into 2 subgroups, mungo-radiata group and angularis group. Four other species referred to the subgeneraPlectotropis (Schumach.) Bak.,Lasiospron (Benth. emend Piper) Maréchal, Mascherpa et Stainier andVigna, V. vexillata (L.) A. Rich.,V. lasiocarpa (Benth.) Verdc.,V. marina (Burm.) Merr. andV. unguiculata (L.) Walp., were also analyzed and they had distinctive carbohydrate compositions. 1d-4-O-methyl-myo-inositol and 1d-5-O-(α-d-galactopyranosyl)-4-O-methyl-myo-inositol were detected in all species examined exceptV. vexillata, V. mungo andV. radiata.     

High and low molecular weight proteolytic activities in prawn (Metapenaeus brevicornis) muscle

Muscle extract of prawn (Metapenaeus brevicornis) expressed high azocoll lytic activity compared to extracts of many other prawn varieties; the activity was also inhibited to a small extent by dithiothreitol. Ammonium sulphate precipitation, subsequent extraction at pH 5.6 and chromatography revealed the occurrence of two types of azocoll lytic activities: one, high molecular weight (630 kDa) and the other low molecular weight (< 30 kDa) enzyme. The former was stimulated by dithiothreitol whereas the latter was inhibited. SDS PAGE of high molecular weight preparation did not show homogeneity but the profile was similar to that of the low molecular weight fraction. Gel filtration of high molecular weight enzyme following incubation at high pH revealed the formation of low molecular weight fractions having activity towards azocoll. Chymotrypsin-like activity associated with high molecular weight enzyme was also susceptible to dissociation by high pH. Azocoll lytic activity of both enzymes was strongly inhibited by 1,10-phenanthroline.     

Bartonella spp. in deer keds, Lipoptena mazamae (Diptera: Hippoboscidae), from Georgia and South Carolina, USA

Deer keds, Lipoptena mazamae (Diptera: Hippoboscidae), were collected from white-tailed deer (Odocoileus virginianus) and humans in Georgia and South Carolina, USA (1 October 2001-6 January 2005) and screened for the presence of DNA from Bartonella spp. Forty deer keds were screened for Bartonella spp. by polymerase chain reaction using primers specific to the riboflavin synthase gene (ribC) of Bartonella. Bartonella species closely related to Bartonella schoenbuchensis and to the etiologic agent of cat-scratch disease (Bartonella henselae) were detected in 10 keds and one ked, respectively.     

Freeze tolerance and accumulation of cryoprotectants in the enchytraeid Enchytraeus albidus (Oligochaeta) from Greenland and Europe

The freeze tolerance and accumulation of cryoprotectants was investigated in three geographically different populations of the enchytraeid Enchytraeus albidus (Oligochaeta). E. albidus is widely distributed from the high Arctic to temperate Western Europe. Our results show that E. albidus is freeze tolerant, with freeze tolerance varying extensively between Greenlandic and European populations. Two populations from sub Arctic (Nuuk) and high Arctic Greenland (Zackenberg) survived freezing at −15 °C, whereas only 30% of a German population survived this temperature. When frozen, E. albidus responded by catabolising glycogen to glucose, which likely acted as a cryoprotectant. The average glucose concentrations were similar in the three populations when worms were frozen at −2 °C, approximately 50 μg glucose mg⁻¹ tissue dry weight (DW). At −14 °C the glucose concentrations increased to between 110 and 170 μg mg⁻¹ DW in worms from Greenland. The average glycogen content of worms from Zackenberg and Nuuk were about 300 μg mg⁻¹ DW, but only 230 μg mg⁻¹ DW in worms from Germany showing that not all glycogen was catabolised during the experiment. Nuclear magnetic resonance spectrometry (NMR) was used to screen for other putative cryoprotectants. Proline, glutamine and alanine were up regulated in frozen worms at −2 °C but only in relatively small concentrations suggesting that they were of little significance for freeze survival. The present study confirms earlier reports that freeze tolerant enchytraeids, like other freeze tolerant oligochaete earthworms, accumulate high concentrations of glucose as a primary cryoprotectant.     

Monthly incidence of Theileria cervi and seroconversion to Babesia odocoilei in white-tailed deer (Odocoileus virginianus) in Texas.

Monthly monitoring of fawns collected from an area in Texas endemic for Theileria cervi and Babesia odocoilei showed that transmission of T. cervi occurred during July and August, a time period consistent with the occurrence of Amblyomma americanum. Seroconversion to B. odocoilei occurred during October to December and possibly continued through January and February. The time of seroconversion was more suggestive of transmission of B. odocoilei by Ixodes scapularis than by Amblyomma americanum.     

低分子量神经丝蛋白（NF—L）的体外组装

Neurofilaments were isolated from bovine spinal cords by ultra-speed centrifugation and examined by negative staining. The neurofilament triplet proteins: NF-L, NF-M and NF-H were purified by DE-52 anion exchange chromatography in the presence of 6 mol/L urea. The reassembly of NF-L under controlled conditions was studied. NF-L can reassemble into 10 nm width filaments within 60 minutes at physiological condition of around 0.15 mol/L NaCl, 2 mmol/L MgCl2, neutral pH(pH 6.8) and 37 degrees C. In 6 mol/L urea, NF-L was examined as 12 nm-diameter particle by low angle rotary shadowing. When dialyzed against reassembly buffer for 20 minutes, some irregular filaments were formed. Further dialyzed for another 40 minutes, the long smooth filaments appeared. Some filaments were unraveled at the end regions, where existed 2-4 subfilaments. Four subfilaments were more often observed. That is to say, the 10 nm-width filament was composed of 4 subfilaments. While dialyzed against the alkaline buffer containing 0.15 mol/L NaCl, NF-L reconstituted into 45-180 nm-long, 10 nm-width filaments, which were not able to elongate into long filaments.     

Freeze tolerance and accumulation of cryoprotectants in the enchytraeid Enchytraeus albidus (Oligochaeta) from Greenland and Europe

The freeze tolerance and accumulation of cryoprotectants was investigated in three geographically different populations of the enchytraeid Enchytraeus albidus (Oligochaeta). E. albidus is widely distributed from the high Arctic to temperate Western Europe. Our results show that E. albidus is freeze tolerant, with freeze tolerance varying extensively between Greenlandic and European populations. Two populations from sub Arctic (Nuuk) and high Arctic Greenland (Zackenberg) survived freezing at −15 °C, whereas only 30% of a German population survived this temperature. When frozen, E. albidus responded by catabolising glycogen to glucose, which likely acted as a cryoprotectant. The average glucose concentrations were similar in the three populations when worms were frozen at −2 °C, approximately 50 μg glucose mg⁻¹ tissue dry weight (DW). At −14 °C the glucose concentrations increased to between 110 and 170 μg mg⁻¹ DW in worms from Greenland. The average glycogen content of worms from Zackenberg and Nuuk were about 300 μg mg⁻¹ DW, but only 230 μg mg⁻¹ DW in worms from Germany showing that not all glycogen was catabolised during the experiment. Nuclear magnetic resonance spectrometry (NMR) was used to screen for other putative cryoprotectants. Proline, glutamine and alanine were up regulated in frozen worms at −2 °C but only in relatively small concentrations suggesting that they were of little significance for freeze survival. The present study confirms earlier reports that freeze tolerant enchytraeids, like other freeze tolerant oligochaete earthworms, accumulate high concentrations of glucose as a primary cryoprotectant.     

Anthelmintic tolerance in free-living and facultative parasitic isolates of Halicephalobus (Panagrolaimidae)

SUMMARY Studies on anthelmintic resistance in equine parasites do not include facultative parasites. Halicephalobus gingivalis is a free-living bacterivorous nematode and a known facultative parasite of horses with a strong indication of some form of tolerance to common anthelmintic drugs. This research presents the results of an in vitro study on the anthelmintic tolerance of several isolates of Halicephalobus to thiabendazole and ivermectin using an adaptation of the Micro-Agar Larval Development Test hereby focusing on egg hatching and larval development. Panagrellus redivivus and Panagrolaimus superbus were included as a positive control. The results generally show that the anthelmintic tolerance of Halicephalobus to both thiabendazole and ivermectin was considerably higher than that of the closely related Panagrolaimidae and, compared to other studies, than that of obligatory equine parasites. Our results further reveal a remarkable trend of increasing tolerance from fully free-living isolates towards horse-associated isolates. In vitro anthelmintic testing with free-living and facultative parasitic nematodes offers the advantage of observing drug effect on the complete life cycle as opposed to obligatory parasites that can only be followed until the third larval stage. We therefore propose Halicephalobus gingivalis as an experimental tool to deepen our understanding of the biology of anthelmintic tolerance.     

Freezing and cellular metabolism in the gall fly larva,Eurosta solidaginis

Summary The effects of extracellular freezing on intracellular metabolism were monitored over both a short (9 h) and long (12 weeks) time course using the freeze tolerant larvae of the gall fly,Eurosta solidaginis.The process of freezing, monitored over the short time course, had no effect upon cellular energy levels (adenylates, arginine phosphate) but initiated a rise in glucose-6-P and lactate levels. This suggests that freezing initiates a shift towards glycolysis as the predominant mode of energy production. The process of thawing at 3°C (after 24 h at –16°C) also had no effect, even transient, on cellular energy levels demonstrating that thawing and the rapid redistribution of water and solutes which must accompany it does not disrupt cellular metabolism. During thawing accumulated lactate was quickly cleared with a t 1/2 of 20–30 min.Long term freezing at –16°C had dramatic effects on energy metabolism. Freezing for up to 1 week had minimal effects with only a small drop in arginine phosphate reserves and an increase in lactate content noted. Between 1 and 2 weeks of freezing, however, larvae showed strong signs of energy stress. The arginine phosphate pool fell from 75% to 30% of control levels, ATP content dropped by 50% and energy charge dropped to 0.75. This state, with continued lactate accumulation, was maintained through 4 weeks of freezing. Between 6 and 12 weeks of freezing energy stress became even greater. Phosphagen and ATP contents dropped to 5 and 25% of control values and energy charge decreased to about 0.50. Despite this stress, however, 94% of larvae survived 12 weeks of freezing with an 86% hatch rate of adults. The data demonstrate that the larvae can survive prolonged periods of winter freezing drawing upon glycolysis and phosphagen reserves to supply the continued basal energy demands of the cell.     

Elaphostrongylus cervi in a population of red deer (Cervus elaphus) and evidence of cerebrospinal nematodiasis in small ruminants in the province of Varese, Italy

Thirty-one faecal samples were collected from red deer in the northern area of Varese, in the Italian region of Lombardy, between August and October 2008. The animals had either been hunted or accidently killed. Examination for internal parasites showed a prevalence of 45.2% for Elaphostrongylus cervi larvae and species identification was confirmed by polymerase chain reaction (PCR). Ninety-seven faecal samples were also collected from two goat flocks grazing in the same area between December 2007 and May 2008. These showed a prevalence of 74.7% for lungworms. Furthermore, the central nervous systems from five goats and one sheep from this area with a history of neurologically related lameness were examined. Histopathology confirmed E. cervi cerebro-spinal nematodiasis in five cases out of six. This study demonstrates E. cervi transmission from wild to domestic ruminants when the animals graze in the same area, and the possible occurrence of clinical disease in infected goats and sheep associated with high prevalence in deer.