Spirocerca lupi Proteomics and Its Role in Cancer Development: An Overview of Spirocercosis-Induced Sarcomas and Revision of Helminth-Induced Carcinomas

Spirocerca lupi is a parasitic nematode of canids that induces a myriad of clinical manifestations in its host and, in 25% of infections, leads to the formation of sarcomas. The description of the protein composition of the excretory and secretory products (Sl-ESP) of S. lupi has shed light on its possible interactions with the host environment, including migration within the host and mechanisms of immunomodulation. Despite this, the process by which S. lupi induces cancer in the dog remains poorly understood, and some hypotheses have arisen regarding these possible mechanisms. In this review, we discuss the role of specific ESP from the carcinogenic helminths Clonorchis sinensis, Opisthorchis viverrini and Schistosoma haematobium in inducing chronic inflammation and cancer in their host’s tissues. The parasitic worms Taenia solium, Echinococcus granulosus, Heterakis gallinarum, Trichuris muris and Strongyloides stercoralis, which have less-characterized mechanisms of cancer induction, are also analyzed. Based on the pathological findings in spirocercosis and the mechanisms by which other parasitic helminths induce cancer, we propose that the sustained inflammatory response in the dog´s tissues produced in response to the release of Sl-ESP homologous to those of other carcinogenic worms may lead to the malignant process in infected dogs.

A survey of intestinal helminths in domestic dogs in a human–animal–environmental interface: the Oloisukut Conservancy, Narok County, Kenya

Dogs living in a domestic–wildlife interface can serve as reservoirs and sentinels of parasites shared among humans, domestic animals and wildlife. In Kenya, the epidemiology of intestinal parasites of dogs and their role as reservoirs of zoonoses is poorly understood, especially in domestic–wildlife interfaces. This study aimed to determine the occurrence of intestinal helminths in domestic dogs in the Oloisukut Conservancy. One hundred dog faecal samples were collected per rectum and examined microscopically following zinc chloride flotation and formal-ether concentration techniques. Genotyping of helminths was achieved by nested polymerase chain reaction of NADH dehydrogenase subunit 1, cytochrome oxidase 1 and partial sequencing. Nine genera were detected by microscopy in 65 (65%) dog faecal samples from 54/76 (71.05%) households. The most frequent helminths were hookworm (39%), Spirometra spp. (17%), taeniids (13%), Toxocara spp. (10%), Trichuris spp. (10%), Spirocerca lupi (5%), Physaloptera spp. (2%), Dipylidium caninum (1%) and Strongyloides spp. (1%). Ancylostoma caninum was the only hookworm species detected in dogs, while Taenia serialis and Taenia madoquae were detected in four and one faecal samples, respectively. This study reports for the first time the molecular detection of the cestodes Spirometra theileri, D. caninum and Mesocestoides sp. in dogs in Kenya. The presence of zoonotic helminths in dogs indicates that the residents of this conservancy are exposed to public health risks. The helminths reported here confirm the interaction of domestic dogs with wildlife. An integrated control programme involving the medical, veterinary and wildlife conservation professionals is needed to avert transmission of infectious diseases to humans, domestic animals and wildlife.

First Report of Spirocerca Lupi Larva in Dung Beetles (Scarabaeus Armeniacus) in Iran: A Morphological and Molecular Identification

Background: Dung beetles are detritivores insects. They naturally use feces of vertebrates as foods and reproduction beds. This leads to frequent contacts between dung beetles and parasitic helminths. The current study was carried out to assess infections of dung beetles with larval stages of helminths in rural areas of Taleqan County, Alborz Province, Iran. In total, 200 dung beetles were randomly collected in June 2017 from the highlands of Taleqan County. Beetles were dissected in normal saline and carefully studied using stereomicroscopy. Morphological characteristics of the recovered larvae were drawn using camera lucida equipped microscope at 400× magnification. Furthermore, genomic DNAs of the recovered larvae were extracted and PCR amplifications of the mitochondrial cytochrome c oxidase subunit 1 (cox1) genes were carried out and the amplicons were sequenced. Results: All collected dung beetles were identified as Scarabaeus armeniacus from Scarabaeidae family (55.5% were male and 44.5% female). Three females of the beetles were infected with nematode larva, morphologically identified as the third-stage of Spirocerca lupi larvae. The average length and width of the larvae were 2.95 (2.81–3.15; CI 95%) and 0.12 (0.1–0.15; CI 95%) mm, respectively. The phylogenetic analysis showed that S. lupi belonged to a clade within Spirocercidae family, well separated from Onchocercidae family. Conclusions: In the current study, S. armeniacus was introduced as a potentially biological vector for the transmission of S. lupi to vertebrates in the region. To the best of the authors’ knowledge, this is the first reported on larval stages of S. lupi in S. armeniacus.

Ultrasonography is insensitive but specific for detecting aortic wall abnormalities in dogs infected with Spirocerca lupi

BackgroundSpirocercosis is caused by the nematode Spirocerca lupi (S lupi). The disease mainly affects dogs and is typically diagnosed by oesophagoscopy or faecal examination; however, these diagnostic tests may deliver false negative results during the migration phase of the nematode. The aim of the present prospective study was to evaluate whether ultrasonography could detect abnormalities in the abdominal aorta, celiac artery, and gastric wall structure as a diagnostic aid to detect S lupi infection in dogs.MethodsOesophagoscopy and a focused abdominal ultrasound scan were performed in 40 dogs that presented to the Koret School of Veterinary Medicine Teaching Hospital, Hebrew University of Jerusalem, with gastrointestinal complaints. Ultrasonography scan findings of 20 dogs with oesophageal nodules, indicating S lupi infection (study group), were compared with those of 20 control dogs.ResultsVascular wall irregularity was significantly more common in the study group than in the control group (9/20 v 1/20, respectively; P=0.008).ConclusionUltrasonographic evaluation of the abdominal aorta, celiac artery, and gastric wall structure is not a sensitive diagnostic marker for spirocercosis in dogs. However, the presence of vascular wall irregularity of the abdominal aorta or celiac artery might indicate S lupi migration.

Helminthes in Feral Raccoon (Procyon lotor) as an Alien Species in Iran

Background: The raccoon, Procyon lotor Linn. (Procyonidae) is native to North and Central America but has been introduced in several European and Asian countries including Japan, Germany and Iran. Objective of this study was to determine frequency of gastrointestinal and tissue helminthes from feral raccoons in Iran. Methods: During 2015-2017, 30 feral raccoons including 12 males and 18 females were collected from Guilan Province, northern Iran (the only region in Iran where raccoons are found). The gastrointestinal tracts and tissues such as lung, liver and muscles were examined for presence of helminthes. Results: Twenty raccoons (66.7%) were found infected with five intestinal helminth species. The prevalence of infection with Strongyloides procyonis Little, 1966 (Nematoda) was 63.3%, Plagiorchis koreanus Ogata, 1938 (Trematoda) (13.3%), Centrorhynchus sp. Lühe, 1911 (Acanthocephala) (10.0%), Camerostrongylus didelphis Wolfgang, 1951 (Nematoda) (3.3%), and Spirocerca lupi Rudolphi, 1809 (Nematoda) (3.3%). No larvae or adult worms were found in other tissues of the examined raccoons. Conclusion: Most of the raccoons were infected with S. procyonis. The public health importance of zoonotic parasites transmittable through raccoons, the rapid control and decrease of raccoon populations and their distribution in Iran are also discussed.