Efficacy of commercially available entomopathogenic nematodes against insect pests of canola in Alberta, Canada.

Certain entomopathogenic nematodes (EPNs) in the families Steinernematidae and Heterorhabditidae are among the most studied biocontrol tools, some of which are commercially available against pest insects. Their use against foliar and subterranean insect pests is largely unexplored in the Canadian Prairies. We conducted a laboratory-based study to produce baseline information on the biocontrol potential of a few commercial EPN species. Percent mortality of flea beetles, diamondback moths (DBMs), lygus, cabbage root maggots, and black cutworms (BCWs) was assessed after 72 hours exposure to Steinernema carpocapsae, S. kraussei, S. feltiae, and Heterorhabditis bacteriophora at varying concentrations (25, 50, 100, and 200 infective juveniles (IJs) per larvae, pupae, or cm2 of soil surface). Irrespective of concentration level, S. carpocapsae and S. kraussei caused significant mortality in DBM and BCW larvae compared with H. bacteriophora.S. kraussei, and S. feltiae were more efficient than S. carpocapsae in controlling root maggot larvae. H. bacteriophora caused zero mortality to root maggots at any concentration. Root maggot pupae were resistant to entry to EPN species tested, likely due to hard outer covering. Compared with root maggot pupae, a moderate level of mortality was observed in DBM pupae, suggesting differential ability of the tested EPNs in killing different life stages of certain pests. All nematode species tested caused low mortality (≤10%) in flea beetle adults. The findings of this investigation form fundamental data essential for carrying out field-based studies on canola and other related crops aimed at control and management of these pest species.

Metabarcoding study to reveal the structural community of strongylid nematodes in domesticated horses in Thailand.

BACKGROUND: Mixed strongylid infections significantly impact equine health and performance. Traditional microscopy-based methods exhibit limitations in accurately identifying strongylid species. Nemabiome deep amplicon sequencing approach previously succeeded in describing the strongylid communities in livestock including equids. However, there are no available studies that describe the structural communities of strongylid parasites in horses in Thailand. Therefore, this study was undertaken encompassing the ITS-2 rDNA metabarcoding assay to characterize strongylid species within horse fecal samples collected from a cohort of yearlings at the largest domesticated stud farm in Thailand. In addition, to investigate the capability of ITS-2 rDNA in assessing the phylogenetic relationships among the identified strongylid species. RESULTS: The study identified 14 strongylid species in the examined equine populations, each with varying prevalence. Notably, Cylicocyclus nassatus and Cylicostephanus longibursatus were identified as the predominant species, with Strongylus spp. conspicuously absent. The phylogenetic analysis of 207 amplicon sequence variants (ASVs) displayed a complex relationship among the investigated cyathostomin species, with some species are positioned across multiple clades, demonstrating close associations with various species and genera. CONCLUSION: The ITS-2 nemabiome sequencing technique provided a detailed picture of horse strongylid parasite species in the studied population. This establishes a foundation for future investigations into the resistance status of these parasites and enables efforts to mitigate their impact.

Improved molecular identification of Strongyloides myopotami in nutrias using fecal samples.

Strongyloides myopotami is an intestinal nematode parasite of nutrias. Identification of S. myopotami is conducted based on the morphological characteristics of adult worms or cultured larvae. To widely and effectively understand the infection in nutrias, it would be preferable to develop the molecular identification using a few grams of the feces. Here, we attempted to identify S. myopotami using DNA extracted from eggs obtained from fecal samples. Among previously reported primer pairs targeting the 18S rRNA gene of Strongyloides spp., most could not be successful. We newly designed primers that successfully amplified the partial sequences in S. myopotami, resulting in being sequenced. Our simple protocol can be useful in nationwide surveys for clarifying the risk of human infection.

Strongyloides stercoralis genotyping in a human population in southwestern Iran.

BACKGROUND: Strongyloidiasis is a neglected tropical disease (NTD) that is caused mainly by Strongyloides stercoralis, with an estimated 600 million people infected worldwide, and in fewer cases by Strongyloides fuelleborni fuelleborni and Strongyloides fuelleborni kellyi. A number of studies have been conducted on the genetic diversity of S. stercoralis in East and Southeast Asia; however, there is very limited corresponding information from West Asian countries, including Iran. METHODS: For Strongyloides worms collected from patients in southwestern Iran, the hypervariable regions I (HVR-I) and IV (HVR-IV) of the nuclear 18S ribosomal DNA (rDNA) locus (SSU) and a fragment of the subunit 1 mitochondrial cytochrome c oxidase gene (cox-1) were sequenced. For a subset of the worms, whole-genome sequencing data were generated. RESULTS: The cox-1 sequences of 136 worms isolated from 23 patients indicated that all isolates were S. stercoralis. Among the cox-1 sequences, 33 polymorphic sites and 13 haplotypes were found. The phylogenetic analysis demonstrated that some sequences clustered fairly closely with sequences from humans and dogs from other parts of the world, while others formed a separate, Iran-specific group. Among 64 S. stercoralis analyzed, we found three of the previously described SSU HVR-I haplotypes, with haplotype II being the most frequent haplotype. In contrast to Southeast Asia, where S. stercoralis heterozygous for different haplotypes at the HVR-I locus are rare, we found 20 worms to be heterozygous for two different HVR-I haplotypes, 18 of which fell into the Iran-specific cox-1 cluster. SSU-heterozygous worms also showed elevated heterozygosity at the whole-genome level. CONCLUSIONS: We conclude that the S. stercoralis population from the Khuzestan province shares much of the genetic diversity with the population in Southeast Asia, but there is an indication of additional genetic input. There appears to be some population structure with different subpopulations, which however do interbreed at least occasionally.

Gastrointestinal parasite community structure in horses after the introduction of selective anthelmintic treatment strategies.

A relatively new method to study the species richness and diversity of nematode parasites in grazing animals is to perform deep sequencing on composite samples containing a mixture of parasites. In this work, we compared species composition of strongyles in two groups of horses as a function of egg count and age, based on a DNA barcoding approach. Faecal egg counts and larval cultures were obtained from nearly 300 horses, i.e., domestic horses (n = 167) and trotters (n = 130) sampled nationwide. The second internal transcribed spacer region (ITS2) of strongyle nematodes in the larval cultures was first amplified using barcoded universal primers and then sequenced on the PacBio platform. Subsequently, bioinformatic sequence analysis was performed using SCATA to assign operational taxonomic units (OTU). Finally, species occurrence and composition were assessed using R. ITS2 sequences were found in the majority (89%) of larval samples. Sequencing yielded an average of 140 (26 to 503) reads per sample. The OTUs were assigned to 28 different taxa, of which all but three could be identified as species. The average relative abundance of the seven most abundant species (all Cyathostominae) accounted for 87% of the combined data set. The three species with the highest prevalence in both horse groups were Cyathostomum catinatum, Cylicocyclus nassatus and Cylicostephanus calicatus, and they were frequently found in different combinations with other species regardless of horse group. Interestingly, this result is largely consistent with a previous Swedish study based on morphological analysis of adult worms. In addition, two migratory strongylids (Strongylus vulgaris and S. edentatus) occurred in few domestic horses and trotters. Except for C. minutus and C. nassatus, which decreased with age, and C. catinatum and S. vulgaris, which increased, no specific trends were observed with respect to horse age. Taken together, these results are broadly consistent with data obtained before the introduction of selective targeted treatment in Sweden in 2007. All in all, our results suggest that this treatment strategy has not led to a significant change in strongyle nematode community structure in Swedish horses. The study also confirms that nemabiome analysis in combination with diversity index analysis is an objective method to study strongyle communities in horses.

Impaired efficacy of fenbendazole and ivermectin against intestinal nematodes in adult horses in Iran.

This study aimed to evaluate the efficacy of fenbendazole and ivermectin on strongyles and Parascaris sp. infecting adult riding horses in three regions with different climates. During 2021 and 2022 fecal specimens were randomly collected from 483 horses older than three years in 31 equestrian clubs in Hamedan (n = 217), Yazd (n = 146) and Tabriz cities (n = 120). Eggs were counted by McMaster technique, and the strongyle larvae were identified using coproculture, PCR and sequencing. Horses with strongyles and Parascaris egg counts ≥150 were enrolled in fecal egg count reduction (FECR) examination following treatment with ivermectin or fenbendazole. In total, 26.5% of examined horses were positive with at least one parasite. Infection rates varied in three cities i.e., 25.8% in Hamedan, 28.8% in Yazd, 25% in Tabriz. Fifty-seven horses had FECR measured. FECR below <90% was observed for IVM-strongyle in two horses in Tabriz, for FBZ-strongyle in two horses in Tabriz and two horses in Hamedan, for IVM-Parascaris in one horse in all three cities, and for FBZ-Parascaris in one horse in Yazd. Furthermore, FECR 90-100% was observed in IVM-Parascaris and FBZ -Parascaris groups in Tabriz. Data herein presented demonstrate different degrees of resistance of strongyles and Parascaris infecting horses in Iran against both ivermectin and fenbendazole. Since non-principled use of anthelminthics is common among horse owners, urgency of test-and-treatment strategy should be educated and implemented by policy-making organizations. Evaluating efficacy of different anthelminthics and choosing the most effective treatment in each region is suggested.

Understanding temporal and spatial distribution of intestinal nematodes of horses using faecal egg counts and DNA metabarcoding.

This study reports the spatial and temporal distribution of ascarid and strongylid nematodes in Thoroughbred horses by age category across different climatic zones in Australia over an 18-month period. Faecal samples (n = 2046) from individual horses were analysed using the modified McMaster technique for faecal egg counts (FECs). Strongylids were identified using PCR-directed next-generation sequencing of the second internal transcribed spacer (ITS-2) of the nuclear ribosomal DNA. Yearlings had the highest prevalence (82%) of strongyle eggs followed by weanlings (79%), foals (58%), wet mares (49%) and dry mares (46%). For Parascaris spp., foals had the highest prevalence (35%) followed by weanlings (21%) and yearlings (10%). The highest mean FECs for Parascaris spp. were observed in foals (525 eggs per gram [EPG] of faeces) while those for strongyles were in yearlings (962 EPG). Among horses that were classified as adults at the time of sampling, 77% (860 of 1119) of mares were low (i.e., <250 EPG) strongyle egg-shedders. Mean strongyle FEC counts were highest in the Mediterranean (818 EPG) followed by summer (599 EPG), winter (442 EPG), and non-seasonal (413 EPG) rainfall zones. Twenty-six nematode species were detected, with Cylicostephanus longibursatus (26.5%), Cylicocyclus nassatus (23.7%) and Coronocyclus coronatus (20.5%) being the most frequently detected species. Their richness and relative abundance varied with horse age, season and climatic zone. In addition, Strongylus equinus and Triodontophorus spp. (T. brevicauda and T. serratus) were also detected. This comprehensive study elucidates spatial (climatic zone) and temporal (i.e., seasonal) trends in prevalence and burdens of intestinal nematodes in Australian horses using non-invasive conventional and molecular methods. The information presented in this study is crucial for developing integrated management strategies to control horse parasites in farmed horses.

Advancing Strongyloides omics data: bridging the gap with Caenorhabditis elegans.

Among nematodes, the free-living model organism Caenorhabditis elegans boasts the most advanced portfolio of high-quality omics data. The resources available for parasitic nematodes, including Strongyloides spp., however, are lagging behind. While C. elegans remains the most tractable nematode and has significantly advanced our understanding of many facets of nematode biology, C. elegans is not suitable as a surrogate system for the study of parasitism and it is important that we improve the omics resources available for parasitic nematode species. Here, we review the omics data available for Strongyloides spp. and compare the available resources to those for C. elegans and other parasitic nematodes. The advancements in C. elegans omics offer a blueprint for improving omics-led research in Strongyloides. We suggest areas of priority for future research that will pave the way for expansions in omics resources and technologies. This article is part of the Theo Murphy meeting issue 'Strongyloides: omics to worm-free populations'.

Strongyloides questions-a research agenda for the future.

The Strongyloides genus of parasitic nematodes have a fascinating life cycle and biology, but are also important pathogens of people and a World Health Organization-defined neglected tropical disease. Here, a community of Strongyloides researchers have posed thirteen major questions about Strongyloides biology and infection that sets a Strongyloides research agenda for the future. This article is part of the Theo Murphy meeting issue 'Strongyloides: omics to worm-free populations'.

Demonstration of reduced efficacy against cyathostomins without change in species composition after pyrantel embonate treatment in Swedish equine establishments.

Consisting of approximately 50 different species, the cyathostomin parasites are ubiquitous in grazing horses. Co-infection with several species is common, and large burdens can cause the fatal disease of larval cyathostominosis. Due to intense anthelmintic drug use, cyathostomin resistance has developed to all available anthelmintic drug groups. Resistance to the anthelmintic drug pyrantel (PYR) has been documented in over 90% of studies published over the past two decades. In Sweden, a study performed in the early 2000s only confirmed resistance in 4.5% of farms. Further, prescription-only administration of equine anthelmintic drugs was enforced in Sweden in 2007. However, it is unknown if this conservative drug use has maintained PYR efficacy in cyathostomins. The aim of the present study was to investigate the effect of PYR on cyathostomin infection in Sweden using fecal egg count reduction tests (FECRTs). Further, the effect of PYR treatment on cyathostomin species composition was studied using metabarcoding. Sixteen farms with at least six horses excreting a minimum of 100 eggs per gram feces were included. Using the current World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines, PYR resistance was demonstrated in nine of farms, with seven farms showing full susceptibility. Farms with low biosecurity measures had significantly lower efficacy of PYR treatment. The most common cyathostomin species were Cylicocyclus nassatus, Cyathostomum catinatum, Cylicostephanus longibursatus, Cys. calicatus, Cys. goldi, Cys. minutus, Coronocyclus coronatus and Cya. pateratum, accounting for 97% of all sequence reads prior to treatment. Of these, Cyc. nassatus and Cya. catinatum had the highest occurrence, accounting for 68% of all sequence reads prior to PYR treatment. Treatment did not significantly affect the species composition. The results highlight the importance of drug efficacy testing when using PYR to treat cyathostomin infection, even when selective anthelmintic treatment and thus low treatment intensity, is used on the farm.

Gastrointestinal parasites in captive olive baboons in a UK safari park.

From the safety inside vehicles, Knowsley Safari offers visitors a close-up encounter with captive olive baboons. As exiting vehicles may be contaminated with baboon stool, a comprehensive coprological inspection was conducted to address public health concerns. Baboon stools were obtained from vehicles, and sleeping areas, inclusive of video analysis of baboon­vehicle interactions. A purposely selected 4-day sampling period enabled comparative inspections of 2662 vehicles, with a total of 669 baboon stools examined (371 from vehicles and 298 from sleeping areas). As informed by our pilot study, front-line diagnostic methods were: QUIK-CHEK rapid diagnostic test (RDT) (Giardia and Cryptosporidium), Kato­Katz coproscopy (Trichuris) and charcoal culture (Strongyloides). Some 13.9% of vehicles were contaminated with baboon stool. Prevalence of giardiasis was 37.4% while cryptosporidiosis was <0.01%, however, an absence of faecal cysts by quality control coproscopy, alongside lower than the expected levels of Giardia-specific DNA, judged RDT results as misleading, grossly overestimating prevalence. Prevalence of trichuriasis was 48.0% and strongyloidiasis was 13.7%, a first report of Strongyloides fuelleborni in UK. We advise regular blanket administration(s) of anthelminthics to the colony, exploring pour-on formulations, thereafter, smaller-scale indicator surveys would be adequate.

Supplementation of minerals and vitamins influences optimal targeted selective treatment thresholds for the control of gastro-intestinal nematodes in lambs.

Targeted Selective Treatment (TST) is a gastrointestinal nematode (GIN) control strategy where anthelmintic treatment decisions are made at an individual animal level. TST has been proven to reduce anthelmintic use and subsequently slow down anthelmintic resistance development, however questions remain regarding optimal TST methods and their applicability across farms. In this study, the influence of Mineral and Vitamin (MV) supplementation on optimal energy utilisation (EU) TST thresholds was assessed on three Welsh farms. In total, 360 lambs were split into two groups, MV supplemented and control, and were treated with an anthelmintic against GIN at the midway point of the experiment. Lambs that improved their EU efficiency post treatment were deemed to have benefited from anthelmintic treatment. Optimal EU TST thresholds was determined for each treatment group per farm using Youden's J statistic where the treatment threshold retrospectively exhibiting the greatest combined sensitivity and specificity in correctly identifying lambs benefiting from treatment was deemed to be optimal. Results demonstrated that the optimal EU TST threshold was higher in MV supplemented groups at 0.72, 0.71 and 0.56 versus 0.58, 0.67, 0.51 for control groups on each respective farm. Identification of lambs for TST was more effective when using an optimised EU TST threshold, compared to when using the standard EU TST threshold of 0.66. The study highlights that applying standard EU TST thresholds may not be appropriate on all commercial farms with factors including MV status as noted in this study likely to influence optimal EU TST thresholds. Additional refinement of TST systems can further strengthen their applicability across sheep flocks.

Diagnostic performance of Strongyloides-specific IgG4 detection in urine for diagnosis of human strongyloidiasis.

BACKGROUND: Detection of parasite-specific IgG in urine is a sensitive method for diagnosis of strongyloidiasis and gives similar accuracy to serum IgG. However, there are no data concerning detection of IgG subclass in urine. To further explore the utility of diagnosis from urine samples, we evaluated the diagnostic performance of IgG4 in urine compared with parasitological and other immunological methods. METHODS: The urine and sera included proven strongyloidiasis (group 1, n = 93), other parasitic infections (group 2, n = 40) and parasite negatives (group 3, n = 93). The performance of Strongyloides-specific IgG4 in urine for diagnosis of strongyloidiasis using fecal examinations as the reference standard was assessed. RESULTS: With fecal examination as a gold standard, Strongyloides-specific IgG4 in urine had 91.4% sensitivity and 93.2% specificity while serum IgG4 had 93.6% sensitivity and 91.0% specificity. IgG4 in both urine and serum had almost perfect diagnostic agreements with fecal examination (Cohen's kappa coefficient was > 0.8). Cross-reactivity to Opisthorchis viverrini and Taenia spp. of IgG4 in urine were 7.5% and 12.5% in serum. Concurrent analyses of total IgG in urine and serum showed that the sensitivities (97.9-100%) and specificities (88.7-91.0%) were similar (P > 0.05). The sensitivity for parasitological examination by the formalin-ethyl acetate concentration technique (FECT) was 49.5% and that for agar plate culture technique (APC) it was 92.6%. CONCLUSION: Our findings showed that specific IgG4 detection in urine yielded similar diagnostic performance to the same biomarkers in serum. This suggests that accurate diagnosis of strongyloidiasis can be performed using urine samples and IgG4 is a valid choice of diagnostic marker. Further assessment is required to assess the utility of urine IgG4 for measuring the response treatment in strongyloidiasis.

Disseminated Coccidioidomycosis With Fungemia and Possible Strongyloides Co-infection.

INTRODUCTION: Coccidioidomycosis is most often an asymptomatic or mild self-limited respiratory infection, but in rare cases it can become disseminated and cause severe disease. CASE PRESENTATION: A 29-year-old man who was originally from Thailand and had been living in Arizona for 2 years presented with intermittent fevers, fatigue, and other nonspecific symptoms, including abdominal pain, nonbloody diarrhea, and pruritic rash. Initial laboratory values showed significant peripheral eosinophilia. Extensive evaluation revealed possible Strongyloides species infection. Shortly after, Coccidioidies species fungemia was found. Fevers and symptoms resolved after adequate treatment. DISCUSSION: Disseminated coccidioidomycosis with fungemia is very rare in immunocompetent individuals. Co-infection with Stronglyloides species is only reported in two other case reports. CONCLUSIONS: We report this case to raise awareness of a rare infection. In adequate epidemiological circumstances, co-infections Coccidioides and Strongyloides species should be considered in presence of fever and eosinophilia.

Caracterização morfológica e morfométrica de estágios larvares de Strongyloides spp, ancilostomídeos e Angiostrongylus spp: subsídios para identificação em amostras ambientais / Morphological and morphometric characterization of larval stages of Strongyloides spp, hookworms and Angiostrongylus spp: subsidies for identification in environmental samples

A identificação precisa de nematódeos de interesse médico-veterinário em amostras de solo ou alimentos é uma ação complexa, devido à grande diversidade de nematódeos no ambiente. O objetivo do estudo foi realizar a caracterização morfológica e morfométrica de diferentes estágios larvários de ancilostomídeos, Strongyloides stercoralis, Strongyloides venezuelensis, Angiostrongylus cantonensis e Angiostrongylus costaricensis, e desenvolver um estudo de similaridade entre espécies do mesmo gênero, a fim de orientar o diagnóstico diferencial com os nematódeos ambientais. As larvas foram fixadas e diversos parâmetros corporais foram mensurados, para os quais foi realizada estatística descritiva e estudo de similaridade. Os resultados médios das larvas padrões foram compatíveis com os descritos para as espécies, com variabilidade em alguns parâmetros. S. stercoralis e S. venezuelensis demonstraram similaridade de 59% para L1 e 79% para L3, com maior diferenciação entre os grupos em relação à extremidade anterior e ao primórdio genital. No pool de larvas de ancilostomídeos, verificou-se uma grande variação nos parâmetros avaliados, especialmente quanto ao comprimento total do corpo. A. cantonensis e A. costaricensis apresentaram 48% de similaridade entre L1 e 76% para L3. Por meio da análise morfométrica e de similaridade verificou-se a possibilidade do aprimoramento do diagnóstico diferencial de nematódeos de origem ambiental. (AU)

Due to the enormous diversity of nematodes in the environment, identifying nematodes of medical and veterinary significance within soil or food samples can be challenging. To facilitate the differential diagnosis with environmental nematodes, this study aimed morphologically and morphometrically characterize various larval stages of hookworms, Strongyloides stercoralis, Strongyloides venezuelensis, Angiostrongylus cantonensi and Angiostrongylus costaricensis. Additionally, a similarity study was conducted among species within the same genus. The larvae were fixated and several body parameters were measured for the analysis, which included a comparison using descriptive statistics. Despite some parameter fluctuation, the average results for standard larvae were consistent with those of the respective species as a whole. The similarity between S. stercoralis and S. venezuelensis was 59% for L1 and 79% for L3, with more pronounced differences observed in the anterior extremity and the genital primordium. The examined parameters exhibited significant variation among the pool of hookworm larvae, particularly concerning the total length of the body. The similarities between A. cantonensis and A. costaricensis larvae ranged from 48% for L1 to 76% for L3. Analyses of morphometric and similarity data provided support for the potential improvement of differentiation between nematodes with environmental origins. This research contributes to enhancing the accuracy of identifying medically and veterinary relevant nematodes present in soil. (AU)

Equine Strongylidae and other parasitic nematodes described by Arthur Looss during 1895-1911 in the collections of the Swedish Museum of Natural History.

Prof. Arthur Looss (1861-1923) was a prolific German parasitologist, who, among other things, authored descriptions of 22 new species of nematodes and 115 new species of trematodes. After his death, his collection (including type material) was split between several institutions: Smithsonian National Museum of Natural History in Washington (USA), Natural History Museum in Berlin and the Natural History Museum in Leipzig (Germany), Gothenburg Museum of Natural History and Swedish Museum of Natural History (Sweden). Here we revise all type specimens of nematodes from the A. Looss collection that are currently preserved in the Swedish Museum of Natural History (Strongylus subtilis, Sclerostomum edentatum, S. vulgare, Cyathostomum labratum, C. coronatum, C. bicoronatum, C. calicatum, C. alveatum, C. catinatum, C. nassatum, C. radiatum, C. elongatum, C. auriculatum, Triodontus minor, T. serratus, C. labiatum and Uncinaria polaris), designate and describe lectotypes wherever deemed necessary and provide catalogue access numbers to all type materials. We also revise all notes and drawings associated with new species that A. Looss described and provide previously unpublished pencilled sketches and ink print-ready drawings of some of these species (Strongylus subtilis, Cyathostomum poculatum, C. radiatum, C. elongatum, C. calicatum, C. auriculatum, Triodontus serratus, Trichostrongylus vitrinus and possibly Necator africanus).

Gastro-intestinal and Respiratoric System Helminths of Domestic Geese in Samsun and Districts

Objective: This research was carried out to determine the digestive and respiratory system helminths of domestic geese collected from Canik, Çarsamba, Havza, Kavak, Terme, and Tekkeköy districts representing Samsun province. Methods: Within the scope of the study, the digestive and respiratory system organs of 64 domestic geese were collected. Organ sets were taken separately, and the contents of each organ were examined. Results: According to macroscopic and microscopic examination, 5 different helminth species were detected in 53 (82.8%) geese: Baruscapillaria obsignata (59.4%), B. anseris (32.8%), Amidostomum anseris (9.4%), Trichostrogylus tenuis (1.6%), and Heterakis sp. (1.6%). Conclusion: At the end of the study, all helminths were found in the digestive system and all of them were nematods. In conclusion, it has been predicted that nematodes that settle in the digestive system of geese are frequently encountered and this may be a problem for goose breeders.

Identification and treatment of Strongyloides cebus in captive ring-tailed lemurs (Lemur catta) in the midwestern United States.

Strongyloides spp. are parasitic enteric nematodes that infect a variety of hosts. While the Strongyloides spp. that affect humans, apes, and Old World primates have been previously identified, this genus has not been as fully investigated in prosimian species such as ring-tailed lemurs (Lemur catta). A high burden (4+) of larvated eggs and larvae were identified in the fecal samples of two captive ring-tailed lemurs during routine intake examination at a zoo in the midwestern United States. Conventional PCR targeting the 18S RNA gene of nematodes was used identified the parasite as Strongyloides cebus. The lemurs were initially treated with 0.2 mg/kg ivermectin orally twice, two weeks apart. Repeat fecal sampling showed persistent, but decreased eggs and larvae from 4+ to 3+. Ivermectin treatment was repeated with the addition of fenbendazole at 50 mg/kg orally once daily for 3 days. No parasite stages were seen on fecal samples one week and six weeks after the last ivermectin indicating successful clearance of the infection.