Ancylostomatidae Research Articles

Smells Like Anthelmintic Resistance-Gastrointestinal Prevalence, Burden and Diversity in Dogs from Portugal.

Anthelmintic resistance has been documented worldwide, but few cases have been reported in dogs. Shelter dogs are a great opportunity to study intestinal helminths and assess their potential resistance to anthelmintic compounds. With these two goals in mind, 361 faecal samples were collected from dogs in 18 municipalities in Portugal, from 19 shelters and 11 private tutors. These samples were analysed using the Mini-FLOTAC before and 13 days after deworming. The percentage of faecal egg count reduction was calculated. Parasitic forms were identified in 22.4% of the samples collected: Trichuris vulpis (10.5%), Toxocara canis (8.0%), members of the family Ancylostomatidae (6.4%), Toxascaris leonina (0.8%), Dipylidium caninum (0.6%) and members of the family Taeniidae (0.3%). The first three nematode parasites showed the highest intensity of infection (2900, 1325, and 1265 eggs per gram, respectively). In the second faecal collection, parasites were present in 20.8% of the samples. The anthelmintics febendazole + pyrantel embonate + praziquantel and praziquantel + fenbendazole were ineffective for T. vulpis and members of the family Ancylostomatidae in 16.2% and 6.9% of the samples, respectively. The parasites identified are all potentially zoonotic. This study is the first to suggest a potential resistance of T. vulpis to anthelmintics.

Gastrointestinal Parasites in Owned Dogs in Serbia: Prevalence and Risk Factors.

Dogs are the most popular pets worldwide. Close contact between dogs and people increases the risk of transmission of various zoonotic parasitic infections. Given the importance of veterinary medicine in preserving the One Health concept, the aim of this research was to identify intestinal parasites that may have zoonotic potential and to evaluate risk factors (individual and environmental). The research was conducted in Serbia in 2022 and 2023 on 382 owned dogs, using qualitative methods of coprological examination with a concentration on parasitic elements. The overall prevalence of intestinal parasites was 62.6%, with the following detected: protozoa: Cystoisospora spp. (9.2%), Sarcocystis spp. (4.5%), Neospora caninum/Hammondia spp. (3.7%), Giardia intestinalis (11.8%); nematoda: Toxocara canis (11.5%), Toxascaris leonina (4.2%), family Ancylostomatidae (38.0%), Trichuris vulpis (21.5%), Capillaria spp. (10.5%); trematoda: Alaria alata (1.6%) and cestodes from the Taeniidae family (1.3%). Factors like age, size and coat length, as well as the way of living, attitude and diet were linked to a significantly higher (p < 0.05) prevalence of intestinal parasites. Based on the results of coprological diagnostics, this research indicates the importance of educating dog owners, conducting routine parasitological tests on their pets and regular deworming strategies.

Risk Factors Associated with Soil-Transmitted Helminths in Dog Feces That Contaminate Public Areas of Warsaw, Poland

A constant increase in dog numbers, especially in large towns, has been observed recently. The presence of dogs in urban spaces increases the risk of pollution by dogs’ feces, which may contain growth forms of parasites including canine, soil-transmitted helminths (cSTHs), most of which have a proven zoonotic potential. This study assessed the frequency of occurrence and estimated the potential risk associated with the presence of cSTHs in dogs’ feces left uncollected in urban areas. The study material consisted of 200 fecal samples obtained from city and dog parks situated in selected Warsaw districts. Each fecal sample was processed using the flotation technique. Eggs of cSTHs, including Toxocara canis, Toxascaris leonina, Trichuris vulpis, and hookworms from the Ancylostomatidae family were found in 23 (11.5%) of the examined fecal samples. The most prevalent species were hookworms from the family Ancylostomatidae (8%). The presence of parasites was confirmed in 14 out of 20 studied locations (70%), including eight city parks (72.7%) and six dog parks (66.7%). City and dog parks did not differ significantly in the frequency of parasite occurrence. This study indicated that dogs’ feces, left uncollected, may cause environmental contamination with cSTHs. It also indicated that the presence of dogs’ feces in public areas and the associated presence of parasites is still a problem.

Risk factors associated with dog endoparasites infection spread in East Slovak Lowland.

This study aimed to determine the prevalence of endoparasites in dog feces from public places, investigate the occurrence of endoparasites in soil, and identify potential risk factors associated with the dog endoparasites infection spread in East Slovak Lowland - the region near the EU border with Ukraine. In a one-year study, a total of 803 dog fecal samples and 148 soil samples from public places were examined for the presence of endoparasite developmental stages. In general, 43.59 % of dog excrements were positive. Six different species of intestinal parasites were detected: Toxocara canis (22.65 %), Trichuris vulpis (14.07 %), family Ancylostomatidae (10.09 %), Capillaria aerophilla (5.60 %), Ascaris spp. (1.49 %). Altogether, 52.03 % of soil samples were positive for at least one endoparasites species. The occurrence of parasitic eggs in the soil was as follows: Ascaris spp. (37.16 %), Toxocara spp. (29.05 %), Trichuris spp. (29.05 %) %), family Ancylostomatidae (2.03 %) and Toxascaris leonina (2.03 %). The occurrence of endoparasites between the towns and villages varied significantly. The distribution of endoparasites in dogs and soil was affected by the population density, the minority people living in the studied territory, the number of people living in poor hygienic conditions with limited access to drinking water and the usage of sewerage. Persisting endoparasitic contamination of the environment in East Slovak Lowland forms a reservoir with zoonotic potential representing public and environmental health problems.

Morphological and molecular comparison of nematodes from the family Ancylostomatidae isolated from selected species of carnivorous mammals in central Poland

The aim of the study was to morphologically and genetically compare parasitic nematodes from the genus Uncinaria found in different hosts. These common parasites belong to hookworm nematodes (family Ancylostomatidae). Worms were collected during dissection of mammals obtained from the Institute of Veterinary Hygiene in Warsaw, where the animals had been tested for rabies. The hosts of the nematodes were European badgers (Meles meles) from the family Mustelidae, as well as red foxes (Vulpes vulpes), dogs (Canis familiaris), and raccoon dogs (Nyctereutes procyonoides) from the family Canidae. The parasites were viewed under a microscope, and identified on the basis of their morphological features characteristic of the species U. stenocephala. Isolated, PCR-amplified, and sequenced rDNA segments containing internal transcribed spacer segments (ITS1 and ITS2) in the gene encoding 5.8S rDNA were also compared. No genetic or morphological differences were found between Uncinaria hookworms obtained from the four different host species. This means that wild raccoon dogs and badgers can be a source and reservoir for the hookworm U. stenocephala that infects dogs.

The survey of soil-transmitted helminth species abundance in Slovakia with an emphasis on parameters important for their distribution.

Soil-transmitted helminths (STH) can be easily dispensable in socially disadvantaged groups. The Roma people represent the group most at risk in Slovakia. This study aimed to investigate the occurrence of STH infections in minorities living with animals under low hygienic conditions and on contaminated soil. Subsequently, we identified the risk assessment factors of the STH transmissions based on parasitological results. In our study, STHs were predominantly found among the Roma communities living in unsanitary conditions. The prevalence of Ascaris lumbricoides among the majority was 0.79%, and Trichuris trichiura was 0.05 %. On the contrary, a community-based cross-sectional survey across eastern Slovakia also found a prevalence of 22.28 and 3.47% for A. lumbricoides and T. trichiura among the Roma population. Inhabitants that belong to the Roma minority had a 37.12 infection OR times higher than non-Roma inhabitants. The Roma people living in the countryside have a 2.23-fold higher chance of getting infected with STH than Roma living in the city. Therefore, soil and domestic animals were also examined for the presence of the STH eggs to show the environmental burden. In general, the presence of STH eggs was confirmed in 26.26% of the soil examined samples. The detailed description is as follows: eggs of Toxocara spp., Trichuris spp., eggs from the family Ancylostomatidae, and Toxascaris leonina. Ascaris eggs were detected only in the soil from localities with low hygienic standards. The probability of contracting the STH eggs in segregated settlements was 15.94 times higher compared to urban or rural areas. In addition to humans, dogs can also be a source of STH eggs in the soil. The STH eggs were confirmed in 43.55% of dog droppings. The most interesting finding was that the eggs of the genus Ascaris were up to 7.93% of dog droppings from localities with a low hygienic standard were positive. This study revealed that climatic factors and the WASH conditions influenced the distribution of STHs to variable degrees. In addition, ethnicity and sanitation were crucial factors in the distribution of STH infection in eastern Slovakia.

The occurence of endoparasites in Slovakian household dogs and cats.

Pets play a pivotal role as definitive or reservoir hosts for many zoonotic parasites. Dogs and cats without any clinical signs may be a carrier for the infection. In a one-year study, collected fecal samples of 257 dogs and 50 cats were examined coproscopically for endoparasite infections. Out of 307 investigated fecal samples, 107 (34.9%) were positive for the presence of the propagative stages of endoparasites In 257 dogs fecal samples, following 12 different species of endoparasites were detected: Giardia duodenalis, Cystoisospora spp., Sarcocystis spp., Hammondia/Neospora-like eggs, Angiostrongylus vasorum larvae, Capillaria aerophila, Crenosoma vulpis, Toxocara spp., Toxascaris leonina, Trichuris vulpis, Strongyloides stercoralis, and eggs from the family Ancylostomatidae. Only 4 different parasitic species were found in 50 domestic cat fecal samples - G. duodenalis cysts Cystoisospora spp., T. cati, and larvae of Aelurostrongylus abstrusus. It was confirmed that significant differences were found concerning age for G. duodenalis, T. canis, S. stercoralis, and family Ancylostomatidae. Close and frequent contact between pets and people increases the risks for the transmission of zoonotic diseases.

Paleoparasitological analysis of a coprolite assigned to a carnivoran mammal from the Upper Pleistocene Touro Passo Formation, Rio Grande do Sul, Brazil.

A paleoparasitological analysis was carried out on a large coprolite assigned to a carnivoran mammal, recovered from the Municipality of Uruguaiana, in the western region of the State of Rio Grande do Sul, Brazil, where the Upper Pleistocene Touro Passo Formation crops out. For this, an individual sample was extracted from the specimen using an electric drill, dissociated with 10% hydrochloric acid solution, washed with distilled water, and sifted through a 500 mesh Tyler sieve. After laboratory processing, the sediment retained on the sieve was mixed with glycerin and examined by optical microscopy, which revealed the presence of 14 protozoan oocysts and three nematode eggs. The morphological characteristics of the oocysts (i.e., spherical shape, thick-walled, internal zygote apparently at the beginning of sporulation, as well as their size) and of the eggs (i.e., ovoidal shape, rounded ends, smooth surface, thin-shelled, embryo in their interior, along with their morphometry) suggest that these specimens belong respectively to the orders Eucoccidiorida and Strongylida (Family Ancylostomatidae) represented by several parasitic species of the alimentary tract of modern carnivore. This is the first record of paleoparasites discovered in a vertebrate host from the Touro Passo Formation.

Occurrence of geohelminths in the soil of children's playgrounds and green areas in the city of Wrocław, Poland.

Pets, strays, and wild animals that excrete dispersal forms of parasites into the soil may be a threat in urban areas. The aim of the study was to determine the level of contamination with geohelminth eggs in community playgrounds (fenced and unfenced), playgrounds in city parks, and a transect found along the banks of the River Oder. In 74 out of 424 examined soil samples, the presence of geohelminths was confirmed (Toxocara spp., Ancylostomatidae and Trichuris spp.). The highest prevalence was noted for Toxocara spp. roundworms. Both total and mean number of eggs in the examined samples, as well as the general prevalence, proved to be diversified in almost all types of development that were compared. Areas near the river emerged as places most exposed to the appearance of geohelminth eggs; playgrounds in city parks were less likely sites; community playgrounds in the city centre were the least common places.

High Prevalence and Diversity of Zoonotic and Other Intestinal Parasites in Dogs from Eastern Spain.

The diversity and frequency of enteric parasites in dog populations in the Castellón province (Eastern Spain) were assessed using a prospective cross-sectional epidemiological survey. A total of 263 canine fecal samples were collected between July 2014 and July 2016. Detection of intestinal parasites was conducted by routine coprological methods. In addition, identification of Giardia duodenalis and Cryptosporidium spp. was carried out by direct immunofluorescence microscopy, whereas the presence of Strongyloides spp. was assessed by real-time PCR in a selected number of specimens. Based on conventional and/or immunofluorescence microscopy examination, 65.8% (95% confidence interval: 59.7-71.5) of the investigated dogs were found infected by at least one gastrointestinal parasite. G. duodenalis (35.4%) and members of the family Ancylostomatidae (27.0%) were the most prevalent protozoan and helminth parasites found, respectively. Other pathogens potentially infective to humans included Toxocara canis (8.0%), Cryptosporidium spp. (6.8%), and Strongyloides spp. (1.1%). Frequency of occurrence of helminthic, but not protozoan, enteroparasites was geographical origin dependent (p = 0.02), with dogs living in coastal areas presenting higher infection rates than those living in inland regions. Similarly, rural dogs were significantly more infected than urban dogs (p < 0.001). Our results revealed that zoonotic agents were common in dogs from the Castellón province. Animals from rural areas and sheltered dogs were particularly at risk of these infections.

The mitochondrial genome of the dog hookworm Ancylostoma caninum (Nematoda, Ancylostomatidae) from Southwest China

The dog hookworm Ancylostoma caninum (Nematoda, Ancylostomatidae) is a blood-feeding intestinal parasitic nematode and can cause ancylostomiasis in humans. In this study, the complete mitochondrial genome of this anthropozoonotic hookworm was sequenced through Illumina deep sequencing technology. The whole genome was 13,721 bp in length and encoded 36 genes including 12 protein-coding genes, 22 transfer RNAs, and 2 ribosomal RNAs. Phylogeny revealed that A. caninum grouped with species from Ancylostomatinae and separated from species of Bunostominae in the family Ancylostomatidae. Amongst the subfamily Ancylostomatinae, three dog-originated A. caninum, regardless of isolate origins, clustered together and were more closely related to the cat hookworm A. tubaeforme and the human hookworm A. duodenale than to the dog/cat hookworm A. ceylanicum and the sea lion hookworm Uncinaria sanguinis. Taken together, the cumulative mitochondrial DNA data provides insights into phylogenetic studies among Ancylostomatidae nematodes.

Contamination of Sandpits with Soil-Transmitted Helminths Eggs in an Urban Environment

Abstract The aim of this study was to monitor the occurrence of the propagative stages of intestinal endoparasites in dog excrements collected within the close proximity of sandpits in an urban environment (Košice, Slovakia) and to determine the level of sandpits contamination with soil-transmitted helminths (STHs). A total of 201 dog faecal samples were examined for the presence of helminth eggs with 10.95 % of the samples being positive. In faeces the most prevalent eggs were those of Toxocara canis (7.46 %). The contamination of sand with STH eggs in 84 sandpits was also investigated. Toxocara spp. eggs were found in 21.43 % of the sandpits. The eggs from the family Ancylostomatidae and Toxascaris leonina were also present. Taenia type eggs and Trichuris sp. eggs occurred less frequently. In some samples, not only monoinfection but also co-infection with eggs of 2‒3 helminth species were detected. In conclusion, the environmental contamination of sandpits with STHs eggs might pose a significant threat to the public health.

Environmental Contamination by enteroparasites present in the feces of dogs in a Pantanal region

Environmental contamination by dog feces in public places is a risk factor for the transmission of enteroparasites, since some intestinal parasites that affect dogs have zoonotic potential. The objective of this work was to describe the prevalence of intestinal parasites present in dog feces (Canis lupus familiaris), using them as indicators of environmental contamination in public urban areas in a region of the Mato Grosso State Pantanal. During the months of May and June of 2016, 120 samples of dog feces were collected in public areas in Caceres-MT. The collected feces were analyzed using an optical microscope in the Parasitology laboratory of the State University of Mato Grosso. For a more accurate diagnosis, two coprological techniques were used in each fecal sample collected, the Hoffman, Pons and Janer method, and the method of Faust et al. To verify the similarity between the richness of parasites species in the different areas, the Jaccard similarity index and the PERMANOVA analysis were used. Among the samples analyzed, 67.5% were positive for at least one intestinal parasite. The most prevalent helminths belong to the family Ancylostomatidae (34.16%), and the most prevalent intestinal protozoan was Giardia spp. (18.33%). The Jaccard index (p <0.05) and the PERMANOVA analysis (R2 = 0.04) showed that the areas are similar in the richness of the species found. It is concluded that dog feces play an important role in the environmental contamination by enteroparasites in this region of the Mato Grosso State Pantanal, representing a risk to the health of humans and other animals.

Segregated settlements present an increased risk for the parasite infections spread in Northeastern Slovakia

Summary The occurrence of parasitic infections among the children, dogs and its association with soil contamination in two villages with different hygiene level standards were analysed. Infections were present in both examined localities, but in the village with higher living standard, a better personal and communal hygiene level and better dogs care a lower occurrence of parasitic germs in soil was detected. High prevalence of protozoa and helminths was observed not only within canine population but also in children throughout the year in the village with lower hygiene and socio-economic standard. We have identified up to 12 taxa of parasites in 127 collected dogs’ excrements and mean prevalence was 71.65 %. The most frequent were eggs of family Ancylostomatidae and Ascaris spp., followed by Toxocara canis, Toxascaris leonina, Giardia duodenalis cysts, Isospora spp. oocysts, eggs of Capillaria aerophila, Trichuris vulpis, Taenia type eggs, Dipylidium caninum, oocysts of Sarcocystis spp. and larvae of Angiostrongylus vasorum. The soil samples collected near dwellings were highly contaminated. Two thirds of samples contained eggs for the most part of family Ancylostomatidae as well as genera Ascaris and Toxocara. Among the kids population helminth ova were present in 53.17 % of stool samples, where the eggs of Ascaris lumbricoides, Trichuris trichiura, Enterobius vermicularis, Hymenolepis diminuta and cysts of G. duodenalis were the most frequent. In contrast, parasitic diseases were not seen in children population living in the locality with common hygiene standard.

Endoparasites of brown bears in Eastern Transylvania, Romania

Limited information is currently available on the parasite fauna of brown bears (Ursus arctos) in Transylvania, Romania. During 2011–2015 we identified endoparasites from 211 scat samples collected from free-ranging bears and 37 samples from organ tissue of adult individuals harvested by hunters in Eastern Transylvania. We found endoparasites in 40.7% of samples overall; 37.9% of scats and 56.8% of harvested bears. We identified 6 nematodes including undetermined species of the family Ancylostomatidae, Baylisascaris transfuga, Crenosoma sp., undetermined species of the order Spirurida, Trichinella sp., and Trichuris sp. We also found one undetermined protozoan species of the subclass Coccidia, the cestode Taenia sp., and the trematode Dicrocoelium dendriticum. We did not detect seasonal variation in B. transfuga incidence, nor in overall parasite prevalences. In Transylvania, brown bears’ space use overlaps with that of domestic animals, creating a potential risk for the transmission of parasite infections. Supplemental feeding of bears and other wildlife species as part of current management practices may increase the potential for parasitic infections by artificially concentrating wildlife.

Ancylostoma ailuropodae n. sp. (Nematoda: Ancylostomatidae), a new hookworm parasite isolated from wild giant pandas in Southwest China

BackgroundHookworms belonging to the genus Ancylostoma (Dubini, 1843) cause ancylostomiasis, a disease of considerable concern in humans and domestic and wild animals. Molecular and epidemiological data support evidence for the zoonotic potential among species of Ancylostoma where transmission to humans is facilitated by rapid urbanization and increased human-wildlife interactions. It is important to assess and describe these potential zoonotic parasite species in wildlife, especially in hosts that have physiological similarities to humans and share their habitat. Moreover, defining species diversity within parasite groups that can circulate among free-ranging host species and humans also provides a pathway to understanding the distribution of infection and disease. In this study, we describe a previously unrecognized species of hookworm in the genus Ancylostoma in the giant panda, including criteria for morphological and molecular characterization.MethodsThe hookworm specimens were obtained from a wild giant panda that died in the Fengtongzai Natural Reserve in Sichuan Province of China in November 2013. They were microscopically examined and then genetically analyzed by sequencing the nuclear internal transcribed spacer (ITS, ITS1-5.8S-ITS2) and mitochondrial cytochrome c oxidase subunit 1 (cox1) genes in two representative specimens (one female and one male, FTZ1 and FTZ2, respectively).ResultsAncylostoma ailuropodae n. sp. is proposed for these hookworms. Morphologically the hookworm specimens differ from other congeneric species primarily based on the structure of the buccal capsule in males and females, characterized by 2 pairs of ventrolateral and 2 pairs of dorsolateral teeth; males differ in the structure and shape of the copulatory bursa, where the dorsal ray possesses 2 digitations. Pairwise nuclear and mitochondrial DNA comparisons, genetic distance analysis, and phylogenetic data strongly indicate that A. ailuropodae from giant pandas is a separate species which shared a most recent common ancestor with A. ceylanicum Looss, 1911 in the genus Ancylostoma (family Ancylostomatidae).ConclusionAncylostoma ailuropodae n. sp. is the fourth species of hookworm described from the Ursidae and the fifteenth species assigned to the genus Ancylostoma. A sister-species association with A. ceylanicum and phylogenetic distinctiveness from the monophyletic Uncinaria Frölich, 1789 among ursids and other carnivorans indicate a history of host colonization in the evolutionary radiation among ancylostomatid hookworms. Further, phylogenetic relationships among bears and a history of ecological and geographical isolation for giant pandas may be consistent with two independent events of host colonization in the diversification of Ancylostoma among ursid hosts. A history for host colonization within this assemblage and the relationship for A. ailuropodae n. sp. demonstrate the potential of this species as a zoonotic parasite and as a possible threat to human health. The cumulative morphological, molecular and phylogenetic data presented for A. ailuropodae n. sp. provides a better understanding of the taxonomy, diagnostics and evolutionary biology of the hookworms.

Stray dogs and cats as potential sources of soil contamination with zoonotic parasites.

The main source of many zoonoses is soil contaminated with feline and canine faeces. Thus, the aim of this study was to estimate the prevalence of intestinal parasites in stray dogs and cats adopted in Lodz shelter (Poland). In total, 163 faecal samples were collected from 95 dogs and 68 cats from 2011 to 2012. The samples were processed by sedimentation techniques using Mini Parasep®SF. Six parasite genera belonging to protozoa, cestoda, and nematoda, were found in dogs, while eight were found in cats. Out of the 163 fecal samples, 37.4% were positive for the presence at least one species of intestinal parasites. The majority of positive dog samples contained eggs from Toxocara and Trichuris genera, and the family Ancylostomatidae, while Toxocara and Taenia eggs, as well as Cystoisospora oocysts, predominated in cat faeces. A significantly higher prevalence of parasites was noted in cats (48.5%) than in dogs (29.5%) (χ2=6.15, P=0.013). The Toxocara genus was the most prevalent parasite in both populations; eggs were found in 27.9% and 16.8% of cats and dogs, respectively. Animals younger than 12 months of age showed higher infection rates with Toxocara, but differences were not statistically significant. The average numbers of Toxocara eggs/gram of faeces in positive puppy and kitten samples were over 5 and 7 times higher than in older dogs and cats, respectively. Mixed infection were found in dogs (5.3%) and cats (8.8%). Cat faeces represent a more important potential source of environmental contamination with zoonotic parasites than dog faeces. Among the detected parasites of stray dogs and cats, Toxocara present an important zoonotic risk for the local human population, especially children.

Occurrence of Endoparasites in Indigenous Zambian Dogs

Abstract This study was conducted in the country of Zambia, Southern Africa, to investigate the occurrence of endo-parasites in indigenous Zambian dogs. Faecal samples were collected from 41 indigenous Zambian dogs from different areas of the Mbabala region in the Southern province of Zambia during the “hot wet” season, although at the time that the samples were collected, the country was experiencing a drought. Faecal samples were analysed using the concentration flotation method with zinc sulphate for the determination of the presence of gastrointestinal parasites. The most prevalent parasites were species from the family Ancylostomatidae (65.0 % infection rate) which followed by: Isospora canis (9.8 %), Dipylidium caninum (4.8 %), and Toxascaris leonina (2.4 %). There were in addition, two cases of co-infections with the family Ancylostomatidae and D. caninum, as well as the family Ancylostomatidae and I. canis.

Gastrointestinal parasites of maned wolf (Chrysocyon brachyurus, Illiger 1815) in a suburban area in southeastern Brazil

We examined 42 maned wolf scats in an unprotected and disturbed area of Cerrado in southeastern Brazil. We identified six helminth endoparasite taxa, being Phylum Acantocephala and Family Trichuridae the most prevalent. The high prevalence of the Family Ancylostomatidae indicates a possible transmission via domestic dogs, which are abundant in the study area. Nevertheless, our results indicate that the endoparasite species found are not different from those observed in protected or least disturbed areas, suggesting a high resilience of maned wolf and their parasites to human impacts, or a common scenario of disease transmission from domestic dogs to wild canid whether in protected or unprotected areas of southeastern Brazil.

Sequence variability in four mitochondrial genes amongBunostomum trigonocephalumisolates from four provinces in China

The present study examined sequence variability in four mitochondrial genes, namely cytochrome c oxidase subunit (cox1), cytochrome b (cytb) and NADH dehydrogenase subunits 1 and 5 (nad1 and nad5), among Bunostomum trigonocephalum isolates from four different geographic regions in China. Ten B. trigonocephalum samples were collected from each of the four provinces (Heilongjiang, Jilin, Shaanxi and Yunnan), China. A part of the cox1 (pcox1), cytb (pcytb), nad1 and nad5 genes (pnad1 and pnad5) were amplified separately from individual hookworms by polymerase chain reaction (PCR) and were subjected to direct sequencing in order to define sequence variations and their phylogenetic relationships. The intra-specific sequence variations within B. trigonocephalum were 0-1.9% for pcox1, 0-2.0% for pcytb, 0-1.6% for pnad1 and 0-1.7% for pnad5. The A+T contents of the sequences were 69.6-70.4% (pcox1), 71.9-72.7 (pcytb), 70.4-71.1% (pnad1) and 72.0-72.6% (pnad5). However, the inter-specific sequence differences among members of the family Ancylostomatidae were significantly higher, being 12.1-14.2% for pcox1, 13.7-16.0 for cytb, 17.6-19.4 for nad1 and 16.0-21.6 for nad5. Phylogenetic analyses based on the combined partial sequences of cox1, cytb, nad1 and nad5 using three inference methods, namely Bayesian inference (Bayes), maximum likelihood (ML) and maximum parsimony (MP), revealed that all the B. trigonocephalum samples form monophyletic groups, but samples from the same geographical origin did not always cluster together, suggesting that there was no obvious geographical distinction within B. trigonocephalum based on sequences of the four mtDNA genes. These results demonstrated the existence of low-level intra-specific variation in mitochondrial DNA (mtDNA) sequences among B. trigonocephalum isolates from different geographic regions.