Ocular infection of cattle with Setaria digitata

One 5-month-old female native Korean calf and a 2-year-old female Holstein cow raised in two farms about 4 km apart from each other in Korea, were found to have the left eye opaque, which included motile white worms in the aqueous humor. The parasite removed from the left eye of the calf was identified as Setaria digitata based on both light and electron microscopic features. The ocular infection with S. digitata reported herein may document the first aberrant case in Korean cattle.     

Comparison of microfilaria concentration method for Setaria digitata infection in cattle and for Dirofilaria immitis infection in dogs

Several peripheral blood microfilaria concentration methods that use Acetone (Acetone test), 2% formalin (modified Knott method), 5% Tween 20 solution, distilled water, 1% or 0.1% SDS were compared for their efficacy in detecting Setaria digitata microfilaria in cattle. The Acetone test was found to be more efficacious than the modified Knott method or the 5% Tween 20 solution test for detecting the S. digitata microfilaria in bovine blood. However, besides the Acetone test, the modified Knott method was also found to be suitable for Dirofilaria immitis microfilaria detection in dogs. SDS and distilled water were found not to be effective as hemolytic agent for the disruption of the red blood cell of both the cattle and dogs. Thus, the Acetone test is recommended for the primary screening of microfilaremia of S. digitata in cattle.     

Patent infection with Setaria digitata in goats in Saudi Arabia.

A survey was carried out on Saudi sheep and goats during 1995, at the Veterinary Diagnostic laboratory, Jeddah, to study Setaria infection in small ruminants in Saudi Arabia. Setaria digitata worms were detected in the abdominal cavity of 5 out of 48 goats (10.4%). Sheep were not found to be infected. All infected goats were adults of 2-4 years of age and originating from the Jeddah, Mecca and Al-Leith areas. Four cases were recorded during January-March and one during August. No lesions due to S. digitata were found in the visceral organs and brains of the infected goats. This is the first record of patent infection with S. digitata in goats.     

Differentiation of Setaria digitata and Setaria labiatopapillosa using molecular markers

5S rRNA intergenic regions of Setaria digitata and Setaria labiatopapillosa were PCR amplified with primers designed from the 5S rRNA gene of Brugia malayi. The ladder-like banding patterns obtained for the amplifications were distinctly different for the two species. Four amplified products were cloned into the pBS vector and completely sequenced. DNA clones from two individual samples of S. digitata, Sd4 and Sd6, showed 97% sequence homology to each other. All sequenced clones showed the presence of the spliced leader (SL) RNA gene with a 22 nucleotide spliced leader sequence. The phylogenetic tree constructed using these data and the 5S rRNA intergenic regions of several other filarial nematodes showed the Setaria species sharing a branch with Dirofilaria. RAPD-PCR analyses identified 107 bands of which 86 were polymorphic (80%). A dendrogram constructed for S. digitata and S. labiatopapillosa separated the two species into two distinct clusters. The polymorphic loci identified by the RAPD-PCR analyses can be studied further to develop species-specific probes/PCR primers for the identification of each species.     

Setaria digitata in cattle of Thailand identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis.

Adult Thai Setaria worms collected from cattle which were bred, housed and slaughtered in Thailand were morphologically identified as Setaria digitata. Furthermore, in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) adult Thai S. digitata had the same protein profiles as adult Japanese S. digitata, but did not possess the protein with a molecular size of 69 kDa which was confirmed in adult S. marshalli. In addition, there were no differences in the protein profiles between male and female S. digitata. In point of the distribution pattern of the proteins ranging from 73 to 64 kDa revealed by 2D-PAGE, there were no differences between Thai and Japanese S. digitata, and between male and female worms of the species.     

Epidemiological investigation of equine hindlimb ataxia with Setaria digitata in South Korea

BackgroundSince 2013, the number of requests for diagnosis for horses based on neurological symptoms has increased rapidly in South Korea. The affected horses have commonly exhibited symptoms of acute seasonal hindlimb ataxia. A previous study from 2015–2016 identified Setaria digitata as the causative agent.ObjectivesThis study is an epidemiological investigation to find out risk factors related to the rapid increase in hindlimb ataxia of horses due to aberrant parasites in South Korea.MethodsAn epidemiological investigation was conducted on 155 cohabiting horses in 41 horse ranches where the disease occurred. The surrounding environment was investigated at the disease-causing horse ranches (n = 41) and 20, randomly selected, non-infected ranches.ResultsHindlimb ataxia was confirmed in nine cohabiting horses; this was presumed to be caused by ectopic parasitism. Environments that mosquitoes inhabit, such as paddy fields within 2 km and less than 0.5 km from a river, had the greatest association with disease occurrence.ConclusionsMost horse ranches in South Korea are situated in favorable environments for mosquitoes. Moreover, the number of mosquitoes in the country has increased since 2013 due to climate change. Additional research is required; however, these data show that it is necessary to establish guidelines for the use of anthelmintic agents based on local factors in South Korea and disinfection of the environment to prevent disease outbreaks.     

山羊脑脊髓丝虫病调查

2000年6～9月,本县思渠镇石坪村、谯家镇兴隆村、垢坪乡河兴村以及沙子镇十二盘村和淇滩镇潮陵村波尔山羊杂交改良示范点的山羊先后发生以后肢麻痹、蹄尖拖地、提举不充分、行走蹒跚、步样强拘、后躯软弱、腰部无力等为主要特征的疫病.据调查5个点山羊共发病69只,其中波尔山羊种公羊2只、本地山羊(系贵州白山羊的代表群种)67只,死亡3只(本地山羊),死亡率为4.3%.笔者根据流行病学调查、临床特征表现、尸体剖检变化,结合实验室诊断,确诊为山羊脑脊髓丝虫病,报告如下.     

唇乳突丝虫感染蚴接种非固有宿主动物致发脑脊髓丝虫病研究

用东乡伊蚊叮吮含有唇乳突丝虫微丝蚴的模型动物——小鼠血液,待微丝蚴在蚊体内发育至感染期时,分离出感染坳,皮下多点接种43只昆明小鼠(每只15～200条)、1只山羊及2只绵羊(每只200～300条)和4匹驹(每匹750～1 250条);将指状丝虫接种到20只昆明鼠体内,比较两种虫体的致病性。结果:唇乳突丝虫感染鼠有16只经1～8 d潜伏期发病,呈现瘫痪、昏迷症状后死亡.实验羊和驹经5～21d潜伏期后均呈不同程度的运动和神经症状,于接种虫体后40～140 d扑杀.经病理学观察,3种动物脑脊髓均呈现虫伤性液化坏死灶及非化脓性脑脊髓炎变化,在其中枢神经系统组织切片中发现丝虫虫体断面或钙化碎片,从而证明唇乳突丝虫可人工感染昆明小鼠、羊、驹发生脑脊髓丝虫病,进而提出该虫可以成为马、羊脑脊髓丝虫病的病原之一。指状丝虫感染鼠死亡率高于唇乳突丝虫感染鼠(P<0.01),初步认为唇乳突丝虫致病性较指状丝虫弱。     

Efficacy of different treatment regimes against setariosis (Setaria tundra,Nematoda: Filarioidea) and associated peritonitis in reindeer

Background

When a severe peritonitis outbreak in semi-domesticated reindeer was noticed in 2003 in Finland, the concerned industry urged immediate preventive actions in order to avoid detrimental effects of S. tundra and further economical losses. A research programme was swiftly initiated to study S. tundra and its impact on the health and wellbeing of reindeer.

Methods

The ultimate aim of this study was to test the efficacy of different treatment regimes against S. tundra and associated peritonitis in reindeer. The timing of the trials was planned to be compatible with the annual rhythm of the reindeer management; (1) the treatment of calves in midsummer, during routine calf ear marking, with ivermectin injection prophylaxis and deltamethrin pour-on solution as a repellent against insect vectors, (2) the treatment of infected calves in early autumn with ivermectin injection, and (3) ivermectin treatment of breeding reindeer in winter. The results were assessed using the post mortem inspection data and S. tundra detection. Finally, to evaluate on the population level the influence of the annual (late autumn-winter) ivermectin treatment of breeding reindeer on the transmission dynamics of S. tundra, a questionnaire survey was conducted.

Results

In autumn, ivermectin treatment was efficient against peritonitis and in midsummer had a slight negative impact on the degree of peritonitis and positive on the fat layer, but deltamethrin had none. Ivermectin was efficient against adult S. tundra and its smf. All the reindeer herding cooperatives answered the questionnaire and it appeared that antiparasitic treatment of reindeer population was intense during the study period, when 64–90% of the animals were treated. In the southern part of the Finnish reindeer husbandry area, oral administration of ivermectin was commonly used.

Conclusion

Autumn, and to a lesser degree summer, treatment of reindeer calves with injectable ivermectin resulted in decreased severity of peritonitis and perihepatitis in reindeer calves due to setariosis. In the case of necessity for animal welfare reasons, treatment during early autumn round ups should be considered. On the population level, massive and routinely applied antiparasitic treatments can improve the health of breeding reindeer and decrease the mortality and the number of carriers but during the outbreak could not prevent its movement and expansion to the North.     

Absence of Wolbachia endobacteria in Sri Lankan isolates of the nematode parasite of animals Setaria digitata

Setaria digitata is an animal filarial parasite with natural hosts of cattle and buffaloes that causes mild disease conditions. Infection of non-permissive hosts such as goats, sheep and horses, by this nematode can cause cerebrospinal nematodiasis that leads to lumbar paralysis and the eventual death of the animals and inflicts considerable economic losses on livestock farmers. Wolbachia are obligate mutualistic endosymbionts for some filarial nematodes and are currently being targeted for the control of diseases caused by these parasites. However, little is known about the occurrence of this endosymbiont in the Setariidae family. In this work, worms collected from infected cattle in Sri Lanka were morphologically identified as S. digitata and tested for the presence of Wolbachia by PCR screening using the WSP- and Wolbachia-specific 16S rRNA and multilocus sequence typing primers that were designed to amplify the gatB, coxA, hcpA, ftsZ and fbpA sequences of Wolbachia. The presence of endobacteria in S. digitata was also examined by whole-mount immunofluorescence staining of the parasites and transmission electron microscopic studies. These analyses did not produce evidence of presence of Wolbachia or any other endosymbiotic bacteria in S. digitata, whereas such evidence was found in Brugia malayi, which was used as a positive control in this study.     

Demonstration of vector competence of Culex quinquefasciatus (Diptera: Culicidae) for Setaria digitata

In Taiwan, Setaria digitata infection causes a lumber paralysis in increasing number of cattle. Culex quinquefasciatus is one of the predominant mosquitoes, and it has been suspected that C. quinquefasciatus acts as a vector to Setaria nematodes prevalence but this was not confirmed. C. quinquefasciatus, Aedes albopictus and A. aegypti of various strains were investigated using an artificial infection system to evaluate their vector competence. After blood feeding at day 14, the number of larvae (stage III) per infected mosquito in A. aegypti (Liverpool strain), A. aegypti (Kaohsiung strain), A. aegypti (Tungan strain), C. quinquefasciatus (Taichung strain) and A. albopictus (Taichung strain) was 1.3 +/- 0.1, 1.3 +/- 0.1, 1.4 +/- 0.1, 1.0 +/- 0.0 and 0 +/- 0.0 (mean +/- S.E.M), respectively. The vector efficiency index of A. aegypti (Liverpool) was the highest among mosquitoes whereas A. albopictus showed a complete refractoriness to the infection. In conclusion, C. quinquefasciatus demonstrates its potential competence for serving as a transmission vector of S. digitata. This mosquito might therefore be responsible, at least in part, for the prevalence of cattle lumbar paralysis in Taiwan. This is the first report of C. quinquefasciatu demonstrating its vector competence for S. digitata.     

Cerebrospinal fluid S-100B concentrations in normal and diseased cattle

We measured the concentrations of S-100B, a marker protein used in humans to detect brain damage, in the cerebrospinal fluid (CSF) of clinically normal cattle (n=15, mean age +/- SD: 31.8 +/- 37.5 months) and of cattle with various inflammatory disorders (n=43, 70.6 +/- 31.9 months). The mean +/- SD CSF S-100B level was 2.9 +/- 1.6 ng/ml in the normal group and 7.0 +/- 7.4 ng/ml in the diseased group. Thirteen diseased cattle that had developed no obvious neurological signs showed abnormally high S-100B concentrations (> 8.0 ng/ml), whereas the two cattle with neurological disorders did not. No particular disease could be related to the S-100B rise. Therefore, it remains inconclusive whether measurement of CSF S-100B concentration is useful in veterinary neurological diagnosis.     

Enterocolitis in cattle associated with Yersinia pseudotuberculosis infection

A syndrome in cattle of diarrhoea and death associated with enteric Yersinia pseudotuberculosis infection is described. Outbreaks occurred during winter and early spring in adult cattle grazing pastures waterlogged by recent flooding or persistent heavy rain. Antibiotic therapy was effective early in the course of the syndrome. At necropsy there was severe acute enterocolitis, and bacteria consistent with Y. pseudotuberculosis were observed in the lesions. This organism could usually be isolated from the intestines of affected animals but was recovered less often from other organs. Representative isolates were identified as Y. pseudotuberculosis serotype III. The association of this syndrome with waterlogged pastures and low temperatures suggests that these conditions favour transmission of Y. pseudotuberculosis infection in cattle. The role of Y. pseudotuberculosis as primary pathogen requires confirmation.     

Novel Propionibacterium infection in cattle

OBJECTIVE: To describe four cases of infection in cattle, from geographically different places, with a presumptive new species of Propionibacterium, which causes granulomatous lesions in the head, thorax, abdomen, pelvic area and skin. PROCEDURE: Gross lesions, ranging from 0.5 to 15 cm and detected during routine carcase inspection at the abattoir, were submitted to the laboratory for routine testing in the National Granuloma Submission Program. The bacterium isolated was identified using morphological characteristics, biochemical reactions, cell wall components, products of fermentation and 16S rRNA gene sequencing. RESULTS: Gross lesions submitted for examination consisted of a fibrous outer capsule enclosing thick yellow pus-like material. A Gram-Glynn stain of the histological sections revealed colonies of Gram-positive, filamentous, branching bacteria. Bacteriological culture, cell wall analysis, biochemical reactions and 16S rRNA sequencing identified the organism as a Propionibacterium sp closely related to P cyclohexanicum and the P freudenreichii cluster. CONCLUSION: This is the first report of a Propionibacterium sp closely related to P cyclohexanicum and the P freudenreichii cluster associated with extensive granulomatous lesions in cattle in Queensland. Sequencing data are suggestive of a previously undescribed species of the Propionibacterium genus.