Genetic characterization of nodular worm infections in Asian Apes.

Parasitic nematodes of Oesophagostomum spp., commonly known, as 'nodular worms' are emerging as the most widely distributed and prevalent zoonotic nematodes. Oesophagostomum infections are well documented in African non-human primates; however, the taxonomy, distribution and transmission of Oesophagostomum in Asian non-human primates are not adequately studied. To better understand which Oesophagostomum species infect Asian non-human primates and determine their phylogeny we analysed 55 faecal samples from 50 orangutan and 5 gibbon individuals from Borneo and Sumatra. Both microscopy and molecular results revealed that semi-wild animals had higher Oesophagostomum infection prevalence than free ranging animals. Based on sequence genotyping analysis targeting the Internal transcribed spacer 2 of rDNA, we report for the first time the presence of O. aculeatum in Sumatran apes. Population genetic analysis shows that there is significant genetic differentiation between Bornean and Sumatran O. aculeatum populations. Our results clearly reveal that O. aculeatum in free-ranging animals have a higher genetic variation than those in semi-wild animals, demonstrating that O. aculeatum is circulating naturally in wildlife and zoonotic transmission is possible. Further studies should be conducted to better understand the epidemiology and dynamics of Oesophagostomum transmission between humans, non-human primates and other wild species and livestock in Southeast Asia.

Parasite-Probiotic Interactions in the Gut: Bacillus sp. and Enterococcus faecium Regulate Type-2 Inflammatory Responses and Modify the Gut Microbiota of Pigs During Helminth Infection.

Dietary probiotics may enhance gut health by directly competing with pathogenic agents and through immunostimulatory effects. These properties are recognized in the context of bacterial and viral pathogens, but less is known about interactions with eukaryotic pathogens such as parasitic worms (helminths). In this study we investigated whether two probiotic mixtures (comprised of Bacillus amyloliquefaciens, B. subtilis, and Enterococcus faecium [BBE], or Lactobacillus rhamnosus LGG and Bifidobacterium animalis subspecies Lactis Bb12 [LB]) could modulate helminth infection kinetics as well as the gut microbiome and intestinal immune responses in pigs infected with the nodular worm Oesophagostomum dentatum. We observed that neither probiotic mixture influenced helminth infection levels. BBE, and to a lesser extent LB, changed the alpha- and beta-diversity indices of the colon and fecal microbiota, notably including an enrichment of fecal Bifidobacterium spp. by BBE. However, these effects were muted by concurrent O. dentatum infection. BBE (but not LB) significantly attenuated the O. dentatum-induced upregulation of genes involved in type-2 inflammation and restored normal lymphocyte ratios in the ileo-caecal lymph nodes that were altered by infection. Moreover, inflammatory cytokine release from blood mononuclear cells and intestinal lymphocytes was diminished by BBE. Collectively, our data suggest that selected probiotic mixtures can play a role in maintaining immune homeostasis during type 2-biased inflammation. In addition, potentially beneficial changes in the microbiome induced by dietary probiotics may be counteracted by helminths, highlighting the complex inter-relationships that potentially exist between probiotic bacteria and intestinal parasites.

Natural nodular worm infection in goats induces eosinophil extracellular DNA trap (EET) formation.

Extracellular DNA Trap (ET) formation by granulocyte is a strong innate immune machinery that plays crucial roles in trapping and killing of pathogens. Here, we show Eosinophil Extracellular DNA Trap (EET) formation in goats naturally infected with nodular worms (Oesophagostomum columbianum, Strongyloidae: Nematoda). By a slaughterhouse based survey, we found that 60% goats were infected with nodular worms. We detected numerous, hard and pale yellow to dark black nodules of variable sizes (0.25-2 cm) in the large intestine and the number of nodules were significantly (p < .05) higher in the cecum (21.7 ± 17.9) than in the colon (10.1 ± 9.9). Histologically, pink colored circumscribed caseous mass was surrounded by a dense zone of infiltration and fibrous proliferation along with massive infiltration of eosinophils in and around the necrotic mass. DAPI staining revealed huge accumulation of extracellular DNA, which formed wide ridge like structure surrounding the necrotic zone. Massive release of eosinophils cationic proteins (ECP), a helmintho-toxic substance, was found into the lesions. Collectively, our results suggest that nodular worm infection induces EETosis and ECP release, and is one of the major parasitic problem affecting Black Bengal goats that causes distortion of normal architecture of the gut wall.

First detection of ivermectin resistance in oesophagostomum dentatum in pigs.

In 2016 suspected reduced ivermectin (IVM) efficacy in Oesophagostomum species in pigs was reported in England. Following this initial report, APHA raised awareness amongst private pig veterinary practitioners of the need to monitor the efficacy of the worm control on pig units. In 2017 another veterinary practitioner highlighted a potential in-field lack of IVM efficacy in treating Oesophagostomum species in sows on another breeder-finisher unit. In this trial, the efficacy of IVM against Oesophagostomum species worms has been investigated to determine whether suspected reduced efficacy (52% reduction in mean faecal egg count 14 days post ivermectin administration) on a mixed indoor and outdoor breeder-finisher pig farm in England reflected true IVM resistance under controlled experimental conditions. On days 0 and 40 of the trial, twenty helminth-naive pigs were artificially infected per os with 5000 Oesophagostomum L3 obtained from the farm under investigation. The pigs were allocated to treatment or control groups (n = 10 per group). Treatment group pigs received IVM (0.3 mg kg body weight) by sub-cutaneous injection as per manufacturer's instructions on day 44. Control group animals were left untreated. Faecal worm egg counts were monitored throughout the trial from day 15 post infection to determine time to patency. On day 50 all pigs were euthanased to assess the worm burdens. Resistance to IVM was confirmed in Oesophagostomum dentatum based on the results of a faecal egg count reduction test (FECRT) and a controlled efficacy test (CET). Efficacy based on mean reduction in faecal egg count of IVM-treated pigs compared to untreated control pigs was 86%. Mean reduction in IVM-treated pig worm burdens was 5% against an adult worm population and 94% against an L3/L4 population. The apparent discrepancy between FECRT and CET efficacy results appears to be due to egg development and/or oviposition suppression in IVM-treated female worms. The detection of IVM resistance in Oesophagostomum species worms for the first time in UK pigs is particularly important considering the global situation where resistance to pyrantel, levamisole and benzimidazole anthelmintics in Oesophagostomum species in pigs have already been reported. The results also provide an opportunity to discuss the wider issue of anthelmintic usage and efficacy on pig farms and highlight the need for wider surveillance for the occurrence of anthelmintic resistance in pigs.

Chabaudstrongylus ninhae (Trichostrongylidae: Cooperiinae) and Oesophagostomum muntiacum (Chabertiidae: Oesophagostominae) in feral alien Reeves's muntjacs on Izu-Oshima Island, Tokyo, Japan.

The naturalization of alien Reeves's muntjacs (Muntiacus reevesi) on Izu-Oshima Island, Tokyo, Japan, has proceeded intensively over the last five decades. To clarify whether the gastrointestinal helminths of these animals were brought from their original endemic area or were newly acquired in Japan, 32 Reeves's muntjacs trapped on the island were parasitologically examined. In addition to Gongylonema pulchrum in the oesophagus (34.4% prevalence), Chabaudstrongylus ninhae (Drózdz, 1967) (Trichostrongylidae: Cooperiinae) and Oesophagostomum muntiacum Jian, 1989 (Chabertiidae: Oesophagostominae) were prevalent in the small (28.1%) and large (46.9%) intestines, respectively. For the first time, these trichostrongylid or chabertiid worms were genetically characterized based on partial nucleotide sequences of the nuclear ribosomal RNA gene (rDNA) and mitochondrial DNA cytochrome c oxidase subunit 1 gene (cox-1), and the phylogenetic relationships with other members of their family were explored. Since these two intestinal nematode species are inherent in muntjacs, this study demonstrates a new distribution of exotic helminth species in Japan in accordance with the naturalization of alien mammalian hosts. The molecular genetic data collected here could assist the taxonomic assessment of morphological variants in different Muntiacus spp. and/or of different geographical origins. Furthermore, our data may help to define the phylogenetic relationships among such isolates.

Economic viability of anthelmintic treatment in naturally infected beef cattle under different nutritional strategies after weaning.

The aim of the present study was to evaluate the effects of treatment with different anthelmintic compounds on the productivity of naturally infected calves and the economic viability of these treatments within extensive breeding systems employing different nutritional strategies after weaning. For this purpose, 4 farms with 42-60 calves naturally infected with gastrointestinal nematodes were selected. The calves were distributed into 6 groups (7-10 animals each) per farm and treated with ivermectin 1%, ivermectin 3.15%, eprinomectin 5%, levamisole 7.5%, albendazole 15%, and control group (no treatment). These animals were evaluated over an experimental period of 150 days. Levamisole 7.5% presented the best capacity for the reduction of eggs per gram (EPG) of feces in all herds evaluated, followed by albendazole 15% and eprinomectin 5%. Parasite resistance to multiple drugs was found in all herds, especially those of Cooperia, Haemonchus, Oesophagostomum, and Trichostrongylus. For farm 1, differences in weight gain and EPG reduction percentages led to a difference of US$285.06 between the levamisole and ivermectin 3.15% groups. Similar findings were noted for the levamisole and ivermectin 1% groups of farm 3, with a difference of US$399.37 because of the final weight gain in these groups. For farms 2 and 4, the ivermectin 3.15% and control groups, respectively, were the most profitable; these unexpected results were possibly influenced by variables not measured during the experimental period. This study suggested that anthelmintic treatments should always precede an efficacy test, once they are demonstrated to be most profitable under adequate breeding conditions, to ensure adequate control of gastrointestinal nematode infection.

Lack of efficacy of monepantel against trichostrongyle nematodes in a UK sheep flock.

Monepantel resistance was diagnosed during routine monitoring of the effectiveness of a farm's roundworm control strategy. Weaned lambs had become ill thrifty and developed diarrhoea, despite the routine use of monepantel. This clinical presentation was caused by trichostrongylosis. The faecal egg count reduction was 76.7% (95% CI: 55.1-82.2%) following treatment with 2.5 mg/kg monepantel. Predominantly Trichostrongylus vitrinus along with small proportions of Oesophagostomum venulosum and Trichostrongylus vitrinus were identified by deep amplicon sequencing of pools of larvae recovered from pre and post monepantel treatment coprocultures and on postmortem examinations. The undifferentiated FECRT showed resistance to monepantel, but not to levamisole, ivermectin, or moxidectin. Examination of farm anthelmintic treatment and animal movement records suggested that treatments before movement onto silage aftermaths, putatively with low numbers of susceptible nematodes in refugia, may have placed a high selection pressure on monepantel resistance. Effective control of parasitic gastroenteritis using anthelmintic drugs is a prerequisite for sustainable sheep production. This case reiterates the need for care when combining anthelmintic treatments with movements to safe grazing, and the value of monitoring of anthelmintic efficacy as part of iterative planned animal health management.

Oesophagostomiasis in non-human primates of Gombe National Park, Tanzania.

Oesophagostomum sp. is a parasitic nematode that frequently infects wild chimpanzees. Although nodular lesions are commonly associated with infection, some wild chimpanzee populations seem to tolerate Oesophagostomum nodular lesions while those at Gombe and other sites suffer from associated morbidity and mortality. From August 2004 to December 2013, we examined demographic (i.e., age, sex) and individual correlates (i.e., fecal consistency, Oesophagostomum egg production) to Oesophagostomum-associated pathology in 14 individually recognized chimpanzees at Gombe Stream National Park, Tanzania. In addition, we characterized Oesophagostomum-associated pathology in 14 individual sympatric primates including baboons, colobus, and cercopithecid monkeys. In five chimpanzees, there was no evidence of any significant underlying disease aside from oesophagostomiasis to explain the thin condition or diarrhea. All five of these chimpanzees had moderate to numerous parasitic nodules. In general, nodules were more numerous in older chimpanzees. Three of four chimpanzees with the highest average Oesophagostomum egg counts in feces collected during the year prior to their death had numerous parasitic nodules at necropsy. In contrast, the four chimpanzees with the lowest egg counts had only moderate numbers of nodules. No association (P = 0.74) was noted between frequency of diarrhea in the year prior to death and the number of nodules noted at necropsy. Nodules were also present in all baboons examined documenting pathology associated with Oesophagostomum infection in wild baboons. In contrast, no lesions were noted in colobus or cercopithecid monkeys, although it is uncertain if they are infected as no fecal studies have been completed in these species to date at Gombe. Sequence of DNA isolated from nodules in chimpanzees matched (99%) Oesophagostomum stephanostomum. Further research is needed to identify the types of Oesophagostomum causing lesions in baboons and to determine if baboons suffer from these infections. Am. J. Primatol. 80:e22572, 2018. © 2016 Wiley Periodicals, Inc.

Duddingtonia flagrans formulated in rice bran in the control of Oesophagostomum spp. intestinal parasite of swine.

Three experimental assays with Duddingtonia flagrans (isolated AC001) were carried out. The growth of the genus Duddingtonia present in formulation of rice bran, its predatory capability on Oesophagostomum spp. infective larvae (L3) in petri dishes (assay 1), its action in faecal cultures with eggs of that parasite (assay 2) and isolate's capability of predation after passing through gastrointestinal tract of swine (assay 3) was evaluated. At assay 3, feces were collected at time intervals of 12, 24, 36, 48, and 60 h after feed animals with the formulation. Assays 1 and 2 showed a statistical difference (p < 0.01) by the F test when comparing the treated group with the control group. At the both assays, was observed in the treated group a reduction percentage of 74.18% and 88.38%, respectively. In assay 3, there was a statistical difference between the treated group and the control group at all collection times (p < 0.01). Regarding the collection periods, there was no statistical difference over time in the treatment group (p > 0.05). The results demonstrate that the fungal isolate AC001 formulated in rice bran can prey on L3 of Oesophagostomum spp., in vitro and after passing through the gastrointestinal tract, without loss of viability. This isolate may be an alternative in the control of Oesophagostomum spp. in swine.

Seasonal dynamics of endoparasitic infections at an organic goat farm and the impact of detected infections on milk production.

This study evaluated patterns and species composition of parasitic infections detected over a 1-year period at an organic goat farm. As a result of coprological examination, the overall prevalence of observed strongylids (99%), coccidia of the genus Eimeria (98%), and Muellerius capillaris lungworms (93%) was calculated. The most prevalent strongylids recovered from incubated fecal samples were Haemonchus contortus (42%), genera Trichostrongylus (23%), Oesophagostomum columbianum (13%), and Teladorsagia circumcincta (11%). A maximum intensity of coccidia infection 5150 oocysts per gram, strongylids infection 9900 eggs per gram and lungworm infection 867.26 larvae per gram were detected. The various effects (including environment, host, and parasites) on milk yield, lactose, protein, and fat were evaluated using generalized linear mixed models. Milk yield (P < 0.0001), milk fat (P < 0.01), and lactose (P < 0.0001) were affected by month, i.e., these parameters were influenced by the month of the year, regardless of the individual goat. With the intensity of infection detected in our study, only protein content was affected (P < 0.01) by parasitic infection (exclusively caused by strongylids). Correlation between measurements from one individual revealed that the goat itself can substantially decrease protein content but has much less of an effect on fat, milk yield, and lactose. Based on our results, we can conclude that a low intensity of parasitic infections does not significantly affect milk yield and the qualitative parameters of milk.

Prevalence of three Oesophagostomum spp. from Tibetan Pigs analyzed by Genetic Markers of nad1, cox3 and ITS1.

Parasitic nematodes of Oesophagostomum spp., commonly known as 'nodular worms' are one of the most widely distributed and prevalent emerging zoonotic nematodes. However, little is known about the prevalence and gene characteristics of those parasites in Tibetan pigs. Therefore, a study was carried out to investigate the prevalence, isolation and identification of Oesophagostomum spp from Tibetan pigs by genetic markers of nad1,cox3 and ITS1 for the first time. The results revealed that the infection rate of O. dentatum and O. quadrispinulatum by genetic markers of nad1 was 81.13%; 35 (66.04%); the O. dentatum and O. quadrispinulatum by genetic markers cox3 was 66.04%, and O. dentatum and O. stephanostomum by genetic markers ITS1 was found to be 77.36%. Interestingly, the O. stephanostomum specie was identified and isolated from 90.48% stomach and 69.23% colon samples by genetic markers of ITS1. The present study, for the first time has described the presence and genetic characterization of Oesophagostomun spp of O. dentatum, O. quadrispinulatum and especially O. stephanostomum in Tibetan pigs from the high and remote Tibetan plateau. A public concern should be raised in terms of economical losses and severe public health problem.

Study of the gastrointestinal parasitic fauna of captive non-human primates (Macaca fascicularis).

The aim of this study was to examine helminths and protozoans in cynomolgus macaques (Macaca fascicularis) imported from registered breeding facilities in China and their relation to health risks for non-human primate handlers in biomedical research centers and in breeding facilities. Fresh fecal samples were collected from a total of 443 M. fascicularis and analyzed by copromicroscopical analysis, immunoenzymatic, or molecular assays. As to helminths, whose eggs were shed in 2.03% of the samples, Trichuris and Oesophagostomum were the only two taxa found, with low prevalence and low eggs per gram (EPG) values. Protozoans were more frequently detected (87.40%), with Entamoeba coli (85.19%) and Endolimax nana (79.26%) as the most prevalent species shed. Other parasites found by fecal smear examination were uninucleated-cyst-producing Entamoebas (78.52%), Iodamoeba bütschlii (42.96%), and Chilomastix mesnili (24.44%), while cysts of Balantidium coli (22.2%) were only observed by sedimentation. No coproantigens of Giardia duodenalis, Cryptosporidium spp., and Entamoeba histolytica complex were detected. Blastocystis sp. infection was noticed in 87.63% of macaques by PCR. These cynomolgus monkeys were infected with many subtypes (ST1, ST2, ST3, ST5, and ST7), where the predominant Blastocystis sp. subtypes were ST2 (77.5%), followed by ST1 (63.5%). Data collected confirmed the presence of potentially zoonotic parasites and a high parasite diversity, suggesting the need for appropriate and sensitive techniques to adequately control them and related health risks for handlers of non-human primates in biomedical research centers and in breeding facilities.

Sequence variation in two mitochondrial DNA regions and internal transcribed spacer among isolates of the nematode Oesophagostomum asperum originating from goats in Hunan Province, China.

The present study examined sequence variability in two mitochondrial DNA (mtDNA) regions, namely cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1), and internal transcribed spacer (ITS) of nuclear ribosomal DNA (rDNA) among Oesophagostomum asperum isolates from goats in Hunan Province, China. A portion of the cox1 (pcox1), nad1 (pnad1) genes and the ITS (ITS1+5.8S rDNA+ITS2) rDNA were amplified by polymerase chain reaction (PCR) separately from adult O. asperum individuals and the representative amplicons were subjected to sequencing from both directions. The lengths of pcox1, pnad1 and ITS rDNA were 366 bp, 681 bp and 785 bp, respectively. The A+T contents of gene sequences were 71.5-72% for pcox1, 73.7-74.2% for pnad1 and 58-58.8% for ITS rDNA. Intra-specific sequence variations within O. asperum were 0-1.6% for pcox1, 0-1.9% for pnad1 and 0-1.7% for ITS rDNA, while inter-specific sequence differences among members of the genus Oesophagostomum were significantly higher, being 11.1-12.5%, 13.3-17.7% and 8.5-18.6% for pcox1, pnad1 and ITS rDNA, respectively. Phylogenetic analyses using combined sequences of pcox1 and pnad1, with three different computational algorithms (Bayesian inference, maximum likelihood and maximum parsimony), revealed distinct groups with high statistical support. These findings demonstrated the existence of intra-specific variation in mtDNA and rDNA sequences among O. asperum isolates from goats in Hunan Province, China, and have implications for studying molecular epidemiology and population genetics of O. asperum.

Molecular identification of the strongyloid nematode Oesophagostomum aculeatum in the Asian wild elephant Elephas maximus.

The transmission of zoonoses by wildlife, including elephants, is a growing global concern. In this study, we screened for helminth infections among Asian wild elephants (Elephas maximus) of the Salakpra Wildlife Sanctuary, Kanchanaburi, Thailand. Elephant faecal samples (45) were collected from the sanctuary grounds during January through November 2013 and assayed individually using the tetranucleotide microsatellite technique. Microscopic examination indicated a high prevalence of strongylids (93.0%) and low prevalences of trichurids (2.3%) and ascarids (2.3%). To identify the strongylid species, small subunit (SSU) rDNA sequences were amplified from copro-DNA and compared with sequences in GenBank. The generated SSU-rDNA sequences comprised five distinct haplotypes that were closely related to Oesophagostomum aculeatum. A phylogenetic analysis that incorporated related nematodes yielded a tree separated into two main clades, one containing our samples and human and domestic animal hookworms and the other consisting of Strongyloides. The present results indicate that O. aculeatum in local elephants is a potential source of helminthiasis in human and domestic animals in this wild-elephant irrupted area.

Nodular Worm Infections in Wild Non-human Primates and Humans Living in the Sebitoli Area (Kibale National Park, Uganda): Do High Spatial Proximity Favor Zoonotic Transmission?

BACKGROUND: Nodular Oesophagostomum genus nematodes are a major public health concern in some African regions because they can be lethal to humans. Their relatively high prevalence in people has been described in Uganda recently. While non-human primates also harbor Oesophagostomum spp., the epidemiology of this oesophagostomosis and the role of these animals as reservoirs of the infection in Eastern Africa are not yet well documented. METHODOLOGY/PRINCIPAL FINDINGS: The present study aimed to investigate Oesophagostomum infection in terms of parasite species diversity, prevalence and load in three non-human primates (Pan troglodytes, Papio anubis, Colobus guereza) and humans living in close proximity in a forested area of Sebitoli, Kibale National Park (KNP), Uganda. The molecular phylogenetic analyses provided the first evidence that humans living in the Sebitoli area harbored O. stephanostomum, a common species in free-ranging chimpanzees. Chimpanzees were also infected by O. bifurcum, a common species described in human populations throughout Africa. The recently described Oesophagostomum sp. found in colobine monkeys and humans and which was absent from baboons in the neighboring site of Kanyawara in KNP (10 km from Sebitoli), was only found in baboons. Microscopic analyses revealed that the infection prevalence and parasite load in chimpanzees were significantly lower in Kanyawara than in Sebitoli, an area more impacted by human activities at its borders. CONCLUSIONS/SIGNIFICANCE: Three different Oesophagostomum species circulate in humans and non-human primates in the Sebitoli area and our results confirm the presence of a new genotype of Oesophagostomum recently described in Uganda. The high spatiotemporal overlap between humans and chimpanzees in the studied area coupled with the high infection prevalence among chimpanzees represent factors that could increase the risk of transmission for O. stephanostomum between the two primate species. Finally, the importance of local-scale research for zoonosis risk management is important because environmental disturbance and species contact can differ, leading to different parasitological profiles between sites that are close together within the same forest patches.

Cracking the nodule worm code advances knowledge of parasite biology and biotechnology to tackle major diseases of livestock.

Many infectious diseases caused by eukaryotic pathogens have a devastating, long-term impact on animal health and welfare. Hundreds of millions of animals are affected by parasitic nematodes of the order Strongylida. Unlocking the molecular biology of representatives of this order, and understanding nematode-host interactions, drug resistance and disease using advanced technologies could lead to entirely new ways of controlling the diseases that they cause. Oesophagostomum dentatum (nodule worm; superfamily Strongyloidea) is an economically important strongylid nematode parasite of swine worldwide. The present article reports recent advances made in biology and animal biotechnology through the draft genome and developmental transcriptome of O. dentatum, in order to support biological research of this and related parasitic nematodes as well as the search for new and improved interventions. This first genome of any member of the Strongyloidea is 443 Mb in size and predicted to encode 25,291 protein-coding genes. Here, we review the dynamics of transcription throughout the life cycle of O. dentatum, describe double-stranded RNA interference (RNAi) machinery and infer molecules involved in development and reproduction, and in inducing or modulating immune responses or disease. The secretome predicted for O. dentatum is particularly rich in peptidases linked to interactions with host tissues and/or feeding activity, and a diverse array of molecules likely involved in immune responses. This research progress provides an important resource for future comparative genomic and molecular biological investigations as well as for biotechnological research toward new anthelmintics, vaccines and diagnostic tests.

Nodule worm infection in humans and wild primates in Uganda: cryptic species in a newly identified region of human transmission.

INTRODUCTION: Soil-transmitted helminths (STHs) are a major health concern in tropical and sub-tropical countries. Oesophagostomum infection is considered endemic to West Africa but has also been identified in Uganda, East Africa, among primates (including humans). However, the taxonomy and ecology of Oesophagostomum in Uganda have not been studied, except for in chimpanzees (Pan troglodytes), which are infected by both O. bifurcum and O. stephanostomum. METHODS AND FINDINGS: We studied Oesophagostomum in Uganda in a community of non-human primates that live in close proximity to humans. Prevalence estimates based on microscopy were lower than those based on polymerase chain reaction (PCR), indicating greater sensitivity of PCR. Prevalence varied among host species, with humans and red colobus (Procolobus rufomitratus) infected at lowest prevalence (25% and 41% by PCR, respectively), and chimpanzees, olive baboons (Papio anubis), and l'hoest monkeys (Cercopithecus lhoesti) infected at highest prevalence (100% by PCR in all three species). Phylogenetic regression showed that primates travelling further and in smaller groups are at greatest risk of infection. Molecular phylogenetic analyses revealed three cryptic clades of Oesophagostomum that were not distinguishable based on morphological characteristics of their eggs. Of these, the clade with the greatest host range had not previously been described genetically. This novel clade infects humans, as well as five other species of primates. CONCLUSIONS: Multiple cryptic forms of Oesophagostomum circulate in the people and primates of western Uganda, and parasite clades differ in host range and cross-species transmission potential. Our results expand knowledge about human Oesophagostomum infection beyond the West African countries of Togo and Ghana, where the parasite is a known public health concern. Oesophagostomum infection in humans may be common throughout Sub-Saharan Africa, and the transmission of this neglected STH among primates, including zoonotic transmission, may vary among host communities depending on their location and ecology.

Parasite population dynamics in pigs infected with Trichuris suis and Oesophagostomum dentatum.

The aim of the present study was to investigate the population dynamics and potential interactions between Trichuris suis and Oesophagostomum dentatum in experimentally co-infected pigs, by quantification of parasite parameters such as egg excretion, worm recovery and worm location. Forty-eight helminth naïve pigs were allocated into four groups. Group O was inoculated with 20 O. dentatum L3/kg/day and Group T with 10 T. suis eggs/kg/day. Group OT was inoculated with both 20 O. dentatum L3/kg/day and 10 T. suis eggs/kg/day, while Group C was kept as an uninfected control group. All inoculations were trickle infections administered twice weekly and were continued until slaughter. Faecal samples were collected from the rectum of all pigs at day 0, and twice weekly from 2 to 9 weeks post first infection (wpi). Six pigs from each group were necropsied 5 wpi and the remaining 6 pigs from each group were necropsied 10 wpi. The faecal egg counts (FEC) and total worm burdens of O. dentatum were dramatically influenced by the presence of T. suis, with significantly lower mean FECs and worm burdens at 5 and 10 wpi compared to single infected pigs. Furthermore, in the presence of T. suis we found that O. dentatum was located more posteriorly in the gut. The changes in the Trichuris population were less prominent, but faecal egg counts, worm counts 5 wpi (57% recovered vs. 39%) and the proportion of infected animals at 10 wpi were higher in Group OT compared to Group T. The location of T. suis was unaffected by the presence of O. dentatum. These results indicate an antagonistic interaction between T. suis and O. dentatum which is dominated by T. suis.

Identification and characterization of new major sperm protein genes from Oesophagostomum dentatum and Oesophagostomum quadrispinulatum from pigs in China.

The present study identified and characterized new major sperm protein (MSP) genes from the two nodule worms Oesophagostomum dentatum and Oesophagostomum quadrispinulatum collected from pigs in China. Total genomic DNA was extracted individually from 10 male nematode samples representing O. dentatum, and 4 male nematode samples representing O. quadrispinulatum. A pair of primers (OMSP1F/MSP1R) was designed based on the MSP gene sequences of Ascaris suum and O. dentatum available in GenBank, and used to amplify the MSP genes from the two porcine nodule worms. The PCR products were purified and subsequently cloned into pGEM-T Easy vector. Recombinants were identified by PCR and sequenced. Sequence analysis revealed that there were two different types of MSP sequences in O. dentatum and O. quadrispinulatum, one contained intron, and the other did not. The lengths of the MSP sequences containing introns were 433 bp or 439 bp in O. dentatum, and 436 bp, 439 bp or 446 bp in O. quadrispinulatum, containing 1 or 2 introns. Five and three new members of the MSP multigene family were identified in O. dentatum and O. quadrispinulatum in this study, respectively. The MSP sequences without introns were 381 bp in length, and can be deduced into 126 amino acids. The sequences of MSP genes containing introns seem to be more conserved than those without introns. The identities of deduced amino acid sequences of the MSP genes containing introns were 96.0-100% within and between the two nodule worms, and were 81.1-93.7% compared with other published MSP sequences of the representative nematodes. The present study identified new MSP genes with introns from O. dentatum and O. quadrispinulatum for the first time. The identification and characterization of newly described MSP genes from O. dentatum and O. quadrispinulatum have implications for further studies of molecular biology and reproduction control of Oesophagostomum spp.

Molecular identification of Oesophagostomum and Trichuris eggs isolated from wild Japanese macaques.

Natural habitat fragmentation and reducing habitat quality have resulted in an increased appearance of Japanese macaques, Macaca fuscata (Gray, 1870), in suburban areas in Japan. To investigate the risk of zoonotic infections, a coprological survey of helminth eggs passed by wild Japanese macaques was carried out in 2009 and 2010 in Shiga Prefecture, Japan. Microscopic examination found helminth eggs in high prevalence, and nucleotide sequencing of DNA extracted from the eggs identified Oesophagostomum cf. aculeatum and Trichuris trichiura. A fecal culture also detected infective larvae of Strongyloides fuelleborni. These zoonotic nematodes pose a potential health issue to local people in areas frequented by Japanese macaques.