Fox Intestines Research Articles

Intestinal system helminths of red foxes and molecular characterization Taeniid cestodes.

Red foxes (Vulpes vulpes) are the most prevalent wild carnivores in the world and definitive hosts of many pathogenic parasites for humans and farm animals. These animals travel great distances in search of prey and nests, and cause contamination of large geographic areas with parasites. For this reason, monitoring the parasitic pathogens of red foxes is particularly important in terms of public and animal health. The goal of this study was to determine the intestinal helminths and molecular characterization of Taenia species of red foxes in Turkey. In this study, 103 red fox intestines obtained from 29 provinces of Turkey were examined with sedimentation and counting technique. Collected helminths were diagnosed according to their morphologic features. Additionally, further molecular analysis (PCR and DNA sequencing) was performed for the identification of Taeniid cestodes. At the end of the study, it was determined that 87.37% (90/103) of red foxes were infected with at least one helminth species. Detected helminths and their prevalence's were Mesocestoides sp. (56.31%), Joyeuxiella echinorhynchoides (33%), Taenia polyacantha (15.53%), Dipylidium caninum (0.97%), Pterygodermatites affinis (51.45%), Toxascaris leonina (45.63%), Uncinaria stenocephala (33%), Oxynema numicidum (20.38%), Toxocara canis (14.56%), Ancylostoma caninum (12.62%), and Trichuris vulpis (1.94%), respectively. Additionally, Pachysentis sp. (37.69%), Centrorhynchus sp. (0.97%) (Acantocephala), and nymphs of Linguatula serrata (20.38%) (Arthropoda) were also detected in the same intestinal samples. This is the most comprehensive study that has been conducted on the intestinal helminthes of red foxes in Turkey. To the best of our knowledge, molecular characterization of T. polyacantha and the detection of O. numicidum, A. caninum, Pachysentis sp., and Centrorhynchus sp. are the first reports in red foxes in Turkey. Our study revealed that red foxes are important hosts for many intestinal helminth species and are link between domestic and sylvatic cycles of these parasites.

Echinococcus multilocularis in Red Foxes in Turkey: Increasing risk in urban

This study was conducted to determine the occurrence of E. multilocularis in foxes and environmental fecal contamination by E. multilocularis in Erzurum, the most highly endemic region for AE in Turkey. The study materials consisted of 50 red fox carcasses collected from 20 counties of Erzurum, Turkey, between October 2015 and February 2016. After the application of the sedimentation and counting technique (SCT), E. multilocularis was identified through the identification of typical morphological structures. Fox fecal samples (n = 600) were also collected from these counties for the isolation of taeniid eggs using the sequential sieving and flotation method (SSFM). Then, the collected adult worms and taeniid eggs were subjected to molecular and sequence analyses. Mature E. multilocularis parasites were found in 42% (21/50) of the fox intestines, with a mean number of 7,806 (150–31,644). The severity of infection was higher in carcasses obtained from the central district (48.6%, 17/35) than in those obtained from the peripheral district (26.7%, 4/15). The prevalence of environmental fecal contamination with E. multilocularis was 10.5% (63/600) in fecal samples collected from all counties of Erzurum. This infection rate was higher in the central district (32.1%, 36/112) than in the peripheral district (5.5%, 27/488; P < 0.0001). In conclusion, contrary to expectation, the prevalence of E. multilocularis positivity was high in urban areas. This could have been due to alterations in the dietary habitats of definitive and intermediate hosts. Therefore, new control strategies are essential to eliminate human AE cases in the future as urbanization advances.

Effect of Accumulation of Heavy Metals in the Red Fox Intestine on the Prevalence of Its Intestinal Parasites.

Simple SummaryHeavy metal pollution of environmental ecosystems has become rather a significant factor in assessing them, as heavy metals can significantly influence animal health. The objective of this study was to examine a possible association between contents of selected heavy metals such as cadmium, copper, lead, chrome, zinc, and manganese in intestines of foxes and between prevalence of fox intestinal parasites. The association was not fully proven. On the contrary, sensitivity of parasites to cadmium was demonstrated; with increasing cadmium content in the intestine of the host, prevalence of parasites decreased to zero. No parasites were found in the intestine, when concentration of accumulated cadmium exceeded the level of 0.05 milligrams per kilogram, which represents the limit for meat (excluding offal) of bovine animals, sheep, pig, and poultry according to the Regulation (EU) No. 488/2014 amending the Regulation (EC) No. 1881/2006). Thus, even cadmium content below the above limit showed an impact on parasite biodiversity.The aim of this study was (i) to compare levels of accumulated heavy metals in the fox intestines with and without parasites. Moreover, our research also dealt with (ii) examination of the relationship between heavy metal content in fox intestines and between the presence of fox intestinal parasites. The intestines of 34 hunter-killed foxes were dissected to detect the occurrence of parasites. In 15 intestinal samples, parasitic intestinal helminths were found. Heavy metal content in small intestine tissue and in parasites was determined using atomic absorption spectrometry (AAS). The prevalence of parasites was significantly dependent on Cd content in the host’s small intestine (p < 0.01). To conclude, the authors suggest that parasites are sensitive to Cd levels; their prevalence in the intestines of the fox host decreases to zero with increasing Cd content.

Epidemiological studies on Echinococcus in Pampas fox (Lycalopex gymnocercus) and European hare (Lepus europaeus) in Buenos Aires province, Argentina

In Argentina, hydatid disease caused by Echinococcus granulosus is widespread. The south of Buenos Aires province, Argentina, is one of the three regions where hydatidosis is endemic. Although domestic dogs and sheep are considered to be the main hosts for E. granulosus, the potential role of wildlife in the local transmission of E. granulosus has not been investigated. The aim of this study was to estimate the hydatidosis/echinococcosis prevalence in European hare (Lepus europaeus) and Pampas fox (Lycalopex gymnocercus), two abundant species with a strong predator-prey relationship in rural areas of Buenos Aires province using different diagnostic tests. A total of 61 fox intestines were examined, finding that 52 (85.2%) harbored at least one helminth species. However, no adult or immature form of Echinococcus sp. was found in the intestinal contents. Coproparasitological analysis and Copro-ELISA followed by Copro-PCR were used as supplementary diagnostic tests. Only one (1.7%) of 59 fecal samples was positive to Taeniidae eggs by coproparasitological analysis, but this same sample was negative by the Copro-ELISA test. The analysis by Copro-ELISA showed 6 of 57 (10.6%) positive samples, but the Copro-PCR tests carried out on these samples were negative to E. granulosus. A total of 6,808 lungs, 3,576 livers, and 3,542 hearts of hunted hares were examined and palpated, but no structure resembling hydatid cysts were detected. Our results suggest that hares and Pampas foxes are not currently important wild reservoirs of E. granulosus in the studied area.

Environmental conditions predict helminth prevalence in red foxes in Western Australia

Red foxes (Vulpes vulpes) are the most common and widely distributed wild carnivore worldwide. These predators harbour a wide range of parasites, many of which may have important conservation, agricultural and zoonotic repercussions. This project investigated the occurrence of helminth parasites from the intestines of 147 red foxes across 14 sampling localities of southwest Western Australia. Helminth parasites were detected in 58% of fox intestines: Dipylidium caninum (27.7% of foxes), Uncinaria stenocephala (18.2%), Toxocara canis (14.9%), Spirometra erinaceieuropaei (5.4%), Toxascaris leonina (4.7%), Taenia serialis (1.4%), Taenia hydatigena (0.7%), unidentified Taenia spp. (4.1%), Brachylaima cribbi (0.7%), Plagiorchis maculosus (0.7%) and an Acanthocephalan; family Centrorhynchidae (2.1%). Importantly, two cestodes of agricultural significance, Echinococcus granulosus and Taenia ovis, were not detected in red foxes in this study, despite the presence of suitable intermediate hosts in the diets of these animals. Parasite richness varied from 1-3 species per host, with average parasite number varying from 1-39 worms (across all helminth species). Regression analyses indicated that the presence of four helminth parasites was related to various environmental factors. The presence of S. erinaceieuropaei (p<0.001), T. leonina (p<0.01) and U. stenocephala (p<0.01) was positively associated with average relative humidity which may affect the longevity of infective stages in the environment. The presence of S. erinaceieuropaei and U. stenocephala (p<0.001) was positively associated with 5-y-average minimum temperature which could reflect poor survival of infective stages through cold winter conditions. The presence of T. canis and U. stenocephala (p<0.001) was positively associated with the percentage cover of native vegetation at each sampling location, which is likely to reflect transmission from native prey species acting as paratenic hosts. These data identify environmental factors affecting transmission and potential distribution of each parasite taxon, and provide important information increasing our understanding of the potential effects of environmental change on parasite ecology.

Segmental Sedimentation and Counting Technique (SSCT): An adaptable method for qualitative diagnosis of Echinococcus multilocularis in fox intestines

A modified Segmental Sedimentation and Counting Technique (SSCT) to examine the presence of Echinococcus multilocularis helminths in segments of fox (Vulpes vulpes) intestine is described and compared to the “gold standard”, SCT. Out of the 358 intestines collected, 117 were E. multilocularis positive. Using SSCT methods we compare the sensitivity of individual or pairs of segments to establish a tradeoff between saving time and the reliability of the diagnosis, especially in areas with low infection intensities. The results show that the analysis of segment S4 associated with segment S1 or S2 give 98.3% sensitivity, with specificity close to 100%. Based on our results and the time saved, we recommend using SSCT for routine examination of fox intestines for large epidemiological studies, particularly where the endemic prevalence of E. multilocularis is low or unknown.

Scraping or shaking?a comparison of methods for the quantitative determination of Echinococcus multilocularis in fox intestines

A modified sedimentation technique (the "shaking in a vessel" technique; SVT) to examine intestines for smaller helminths such as Echinococcus multilocularis is described and compared with the intestinal scraping technique (IST). Out of 356 foxes, 26 were E. multilocularis positive, 19 using IST (sensitivity 73.1%) and 25 with SVT (sensitivity 96.2%) after IST. Especially low infection intensities went undetected with IST. The result is comparable to the established sedimentation and counting technique (SCT). SVT is recommended for the routine examination of fox intestines as an alternative to SCT.

Lethal effects of freezing Echinococcus multilocularis eggs at ultralow temperatures.

Methods for killing Echinococcus multilocularis eggs within stool or intestinal samples, without damaging the diagnostic value of the sample, would significantly reduce the risk of animal health providers acquiring alveolar hydatid disease. The first objective of this study was to determine whether E. multilocularis eggs located in fox intestines can survive storage at -70 C for at least 4 days. Results showed that none of 72,000 E. multilocularis eggs remained infectious to defined strains of mice under these conditions, yet, similar eggs recovered from nonfrozen carcasses stored at 4 C for the same time period were viable. The structural identities of adult worms and eggs were not significantly altered by the freezing and thawing processes. These results indicate that ultracold temperatures can be used to kill or inactivate E. multilocularis eggs, making them safe to handle when diagnosing this parasite in definitive hosts. The second objective of this study was to determine whether E. multilocularis eggs could survive freezing to -70 C if commonly used cryopreservation protocols were used. The use of the cryoprotectant solution, 5% dimethyl sulfoxide-35% saline-60% lamb serum, with a -1 C/min freezing rate was unable to prevent the eggs from being killed by freezing to -70 C. Rapid cooling by plunge freezing into liquid nitrogen was also lethal to E. multilocularis eggs. Only a few of the many potential cryopreservation protocols were tested in this study, so it is not yet possible to completely rule out the possibility of preserving these eggs at ultralow temperatures, but it does indicate that temperatures below -70 C are lethal to eggs even under favorable storage conditions.