- The impact of global climate change on the spread of parasitic nematodes [Journal Article]
- APAnn Parasitol 2017; 63(1):15-20
- Climate changes may influence the frequency, intensity and geographical distribution of parasites, directly affecting their dispersive stages in the environment (eggs, larvae) and, indirectly, the la...
Climate changes may influence the frequency, intensity and geographical distribution of parasites, directly affecting their dispersive stages in the environment (eggs, larvae) and, indirectly, the larvae living mainly in invertebrate intermediate hosts. In biologically diverse nematodes climate warming contributes to the increase in the range of distribution, colonization of new hosts and modification of their development cycles. This is particularly acute in the Arctic and pertains, for instance, to nematodes Ostertagia gruehneri and Setaria tundra parasitizing reindeer Rangifer tarandus and Umingmakstrongylus pallikuukensis in musk oxen (Ovibos moschatus). Increase in range expansion of mosquitoes Culicidae caused that nematodes of the genus Dirofilaria, especially D. repens, have been listed in autochthonous invasions even in the northern and eastern European countries. In addition, extended range of occurrence is also shown by Ancylostoma braziliense – a parasite of carnivores in the tropical and subtropical countries. In recent years over 20 cases of autochthonous creeping eruption (CE) caused by cutanea larva migrans (CLM) A. braziliense were detected in people in southern Europe (Italy, Spain, France, Germany).
- The role of domestic dogs in the transmission of zoonotic helminthes in a rural area of Mekong river basin. [Journal Article]
- APActa Parasitol 2017 Jun 01; 62(2):393-400
- Dogs have been bred since ancient times for companionship, hunting, protection, shepherding and other human activities. Some canine helminth parasites can cause significant clinical diseases in human...
Dogs have been bred since ancient times for companionship, hunting, protection, shepherding and other human activities. Some canine helminth parasites can cause significant clinical diseases in humans as Opisthorchis viverrini causing cholangiocarcinoma in Southeast Asian Countries. In this study, socio-cultural questionnaire, canine parasitological analysis, necropsy, parasite molecular confirmation and dog roaming data were evaluated in Savannakhet, Lao-PDR, a typical Mekong Basin area. Dog owners comprised 48.8% of the studied population, with 61.2% owning one dog, 25.1% 2 dogs, 8.5% 3 dogs and 1.8% owning more than 4 dogs. Data from GPS logger attached to dogs showed they walked from 1.4 to 13.3 km per day, covering an area of 3356.38m2 average, with a routine of accessing water sources. Thirteen zoonotic helminth species were observed. Causative agents of visceral and cutaneous larva migrans occurred in 44.1% and 70% of the samples respectively. Spirometra erinaceieuropaei was detected in 44.1% of samples. Importantly, O. viverrini was found in 8.8% of samples. Besides the known importance of dogs in the transmission of Ancylostoma spp., Toxocara spp. and S. erinaceieuropaei, the observed roaming pattern of dogs confirmed it as an important host perpetuating O. viverrini in endemic areas; their routine access to waterbodies may spread O. viverrini eggs in a favorable environment for the fluke development, facilitating the infection of fishes, and consequently infecting humans living in the same ecosystem. Therefore, parasitic NTDs control programs in humans should be done in parallel with parasite control in animals, especially dogs, in the Mekong River basin area.
- Enzyme-linked immunosorbent assays for coproantigen detection of Ancylostoma caninum and Toxocara canis in dogs and Toxocara cati in cats. [Journal Article]
- JVJ Vet Diagn Invest 2017 Apr 01; :1040638717706098
- We report the development and field validation of 2 ELISAs for the detection of Ancylostoma caninum or Toxocara canis coproantigens in the feces of dogs with experimental and natural infections, and ...
We report the development and field validation of 2 ELISAs for the detection of Ancylostoma caninum or Toxocara canis coproantigens in the feces of dogs with experimental and natural infections, and evidence of cross-reactivity with respective feline counterparts. A. caninum-specific coproantigens were detected in feces of experimentally infected dogs starting at 9 d post-infection (dpi), whereas eggs were not seen until 23 dpi. T. canis-specific coproantigens were detected in 3 of 5 experimentally infected dogs by 31 dpi, and 4 of the 5 animals by 38 dpi. T. canis eggs were seen in feces of 4 of the 5 animals by 38 dpi. One dog had delayed coproantigen detection and low egg output. Additionally, 817 canine and 183 feline fecal samples from naturally infected animals tested by flotation were subjected to coproantigen ELISA testing. Of these 1,000 canine and feline samples, 13 and 23 samples, respectively, were positive for "hookworm" or "roundworm" eggs; 19 and 26 samples were ELISA positive, respectively. The T. canis ELISA detected T. cati coproantigen in cat fecal samples. Discrepant ELISA and flotation results were obtained for 16 hookworm- and 13 roundworm-positive samples. Re-examination of the egg-positive, ELISA-negative samples indicated several instances of possible misidentification or coprophagy, whereas detection of antigen in samples without egg observations is likely a reflection of true infection status with egg shedding below detection levels. There is good indication, based on accumulated field data, that these antigen tests also detect other hookworm and ascarid species.
- Efficacy of afoxolaner plus milbemycin oxime chewable tablets (NexGard Spectra(®), Merial) against adult Ancylostoma ceylanicum hookworm, in dogs. [Journal Article]
- VPVet Parasitol 2017 Apr 01
- A fixed-combination chewable tablet incorporating afoxolaner plus milbemycin oxime (NexGard Spectra(®), Merial) was tested in purpose-bred Beagle dogs for efficacy against adult Ancylostoma ceylanicu...
A fixed-combination chewable tablet incorporating afoxolaner plus milbemycin oxime (NexGard Spectra(®), Merial) was tested in purpose-bred Beagle dogs for efficacy against adult Ancylostoma ceylanicum hookworms. Sixteen dogs were inoculated each by oral administration of approximately 500 infective larvae of A. ceylanicum. Seventeen days after inoculation, the dogs were weighed and allocated randomly to be treated with afoxolaner plus milbemycin oxime chewable tablets or to remain untreated. Commercial chewable tablets of different strength were combined to deliver doses as close as possible to the minimum effective dose of 2.5mg afoxolaner plus 0.5mg milbemycin oxime per kg body weight. Parasites were recovered and counted for determination of efficacy seven days after treatment. All eight dogs that had been left untreated were harboring adult A. ceylanicum (geometric mean, 317.8; range, 210-428) while only one and nine A. ceylanicum were recovered from two of the eight dogs treated with afoxolaner plus milbemycin oxime chewable tablets (geometric mean, 0.5; p<0.0001). Thus, 99.9% efficacy against induced infection of A. ceylanicum was obtained by the use of oral NexGard Spectra(®) at the minimum effective dose. Treatment with afoxolaner plus milbemycin oxime chewable tablets was well accepted and safe.
- Efficacy of a new spot-on formulation of selamectin plus sarolaner against Ancylostoma tubaeforme and Toxocara cati in cats. [Journal Article]
- VPVet Parasitol 2017; 238 Suppl 1:S31-S35
- The efficacy of a new spot-on formulation of selamectin plus sarolaner for cats was evaluated against induced infections with Ancylostoma tubaeforme (hookworm) and Toxocara cati (roundworm). Five lab...
The efficacy of a new spot-on formulation of selamectin plus sarolaner for cats was evaluated against induced infections with Ancylostoma tubaeforme (hookworm) and Toxocara cati (roundworm). Five laboratory studies were conducted using adult, purpose-bred cats. Four of the studies were designed to evaluate efficacy of the combination against A. tubaeforme, the dose-limiting gastrointestinal nematode species for selamectin. In two of these studies non-interference between selamectin and sarolaner was also evaluated. The fifth study evaluated efficacy of the combination against mixed infections of A. tubaeforme and T. cati. The hookworm isolates in three studies were of US origin, as was the roundworm isolate. In the two remaining studies, cats were inoculated with a hookworm isolate of European origin. Cats were inoculated with 150 (±50) to 200 (±50) infective hookworm larvae 30-42days prior to treatment and with 400 infective roundworm eggs 60days prior to treatment. Cats were ranked by pre-treatment faecal egg counts and randomly allocated to different treatment groups. In all studies, cats were treated at the minimum label dose to provide 6.0mg selamectin per kg bodyweight. All animals were euthanized 7-10days after treatment for worm counts. Efficacy was calculated based on the reduction of the geometric mean worm counts in the treated groups versus the placebo-treated control groups. The efficacy against adult hookworms was 99.2%, 94.3% and 100% in three of these studies, and was lower in the remaining two studies. The efficacy against T. cati was 100%. Furthermore, non-interference between sarolaner and selamectin was demonstrated. Thus, a single topical application of the new spot-on formulation of selamectin plus sarolaner at the minimum label dose is effective in the treatment of adult hookworm and roundworm infections in cats.
- Development of new microsatellites for the hookworm Ancylostoma caninum and analysis of genetic diversity in Brazilian populations. [Journal Article]
- IGInfect Genet Evol 2017 Mar 10; 51:24-27
- Considering the great efforts towards formulating a vaccine against hookworms, and the concerns about the spread of drug resistance through hookworm populations, it is justified to study the molecula...
Considering the great efforts towards formulating a vaccine against hookworms, and the concerns about the spread of drug resistance through hookworm populations, it is justified to study the molecular diversity and population genetic structure of these nematodes. This work had the aim to develop microsatellite markers to investigate the genetic structure and the molecular diversity of Brazilian populations of Ancylostoma caninum. Seven microsatellites markers were successfully used to characterize five Brazilian populations. These findings may contribute to a better comprehension of the ecology, patterns of transmission, drug resistances and development of immunotherapeutic strategies in hookworms.
- An investigation of parasitic infections and review of molecular characterization of the intestinal protozoa in nonhuman primates in China from 2009 to 2015. [Journal Article]
- IJInt J Parasitol Parasites Wildl 2017; 6(1):8-15
- Parasites are a well-known threat to nonhuman primate (NHP) populations, and potentially cause zoonotic diseases in humans. In this study, the basic data was provided of the parasites in NHPs and the...
Parasites are a well-known threat to nonhuman primate (NHP) populations, and potentially cause zoonotic diseases in humans. In this study, the basic data was provided of the parasites in NHPs and the molecular characterization of the Enterocytozoon bieneusi, Giardia duodenalis, Cryptosporidium spp., and Entamoeba spp. were reviewed, which were found in these samples. A total of 3349 fecal samples were collected from 34 species reared at 17 districts in zoos, farms, free-range, or research laboratories, and examined microscopically. Eleven genera of intestinal parasites were detected: five genera of protozoans (Isospora spp., Entamoeba spp., Giardia sp., Cryptosporidium spp., and Cyclospora spp.) and six genera of helminths (Trichuris spp., Strongyloides spp., Ascaris spp., Physaloptera spp., Ancylostoma spp., and Enterobius spp.). The overall sample prevalence of parasitic infection was 54.1% (1811/3349). Entamoeba spp. was the most prevalent (36.4%, 1218/3349). The infection rate was the highest in free-range animals (73.0%, 670/918) (P < 0.01) and Guangxi Zhuang autonomous region (64.8%, 566/873). Mixed infections were mostly detected for Entamoeba spp., Trichuris spp., and Strongyloides spp.. Molecular characterization was reviewed of Enterocytozoon bieneusi, Giardia duodenalis, Cryptosporidium spp., and Entamoeba spp., as these are zoonotic species or genotypes. This parasitological data for NHPs in China, provides important information for veterinarians and public health authorities for the elimination of such parasites and monitor the potential transmission of zoonotic infections from NHPs.
- Blastocystis subtyping and its association with intestinal parasites in children from different geographical regions of Colombia. [Journal Article]
- PlosPLoS One 2017; 12(2):e0172586
- Blastocystis is a common enteric protist colonizing probably more than 1 billion people with a large variety of non-human hosts. Remarkable genetic diversity has been observed, leading to the subdivi...
Blastocystis is a common enteric protist colonizing probably more than 1 billion people with a large variety of non-human hosts. Remarkable genetic diversity has been observed, leading to the subdivision of the genus into multiple subtypes (ST), some of which are exclusively found in non-human hosts. The aim of this study was to determine the distribution of Blastocystis STs/18S alleles in symptomatic (abdominal pain, anal pruritus, diarrhea, headache, nauseas and/or vomit) and asymptomatic children from nine geographical regions of Colombia. A total of 2026 fecal samples were collected as part of a national survey to estimate the frequency of intestinal parasites in children. A set of 256 samples that were Blastocystis positive was finally selected. The samples were submitted to DNA extraction, Real Time PCR and sequencing using Blastocystis-specific primers targeting the small subunit rRNA gene for ST identification. DNA of Ascaris lumbricoides (16.4%), Trichuris trichiura (8.2%), hookworms (Necator americanus/Ancylostoma duodenale) (7.3%), Giardia duodenalis (23.1%), Entamoeba complex (82%), Entamoeba coli (55%), Hymenolepis nana (0.8%), Endolimax nana (33.2%) and Neobalantidium coli (2.7%) was detected in the Blastocystis-positive samples. We detected ST1 (21.4%), ST2 (19.5%), ST3 (55.5%), ST4 (0.8%), ST6 (2%) and ST7 (0.8%); alleles 1, 2, 4, 81, 82 and 83 for ST1; alleles 9, 11, 12, 15, 67, 71 and 73 for ST2; alleles 34, 36, 38, 45, 49, 55, 134 and 128 for ST3; allele 42 for ST4; allele 122 for ST6, and allele 142 for ST7. Further studies implementing high-resolution molecular markers are necessary to understand the dynamics of Blastocystis transmission and the role of this Stramenopila in health and disease.
- The mitochondrial genome of Ancylostoma tubaeforme from cats in China. [Journal Article]
- JHJ Helminthol 2017 Feb 20; :1-12
- Ancylostoma tubaeforme may infect canids, felids and humans, and pose a potential risk to public health. Polymerase chain reaction (PCR) techniques were used to amplify the complete mitochondrial (mt...
Ancylostoma tubaeforme may infect canids, felids and humans, and pose a potential risk to public health. Polymerase chain reaction (PCR) techniques were used to amplify the complete mitochondrial (mt) genome sequence of A. tubaeforme from cats and to analyse its sequence characteristics after molecular identification based on the internal transcribed spacer ITS1+ sequence. The results show that the complete mt genome sequence (GenBank accession number KY070315) of A. tubaeforme from cats was 13,730 bp in length, including 12 protein-coding genes, 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes, two non-coding regions and an AT-rich region. The nucleotide content of A and T was 77.93%, biased toward A and T. Twelve protein-coding genes used ATT, TTG and GTG as initiation codons, and TAA, TAG, TA and T as termination codons. The length of the 22 tRNA genes ranged from 52 to 62 bp, their predicted secondary structures were D loops and V loops. The lengths of the two rRNAs were 958 and 697 bp. Phylogenetic analyses showed that A. tubaeforme from cats was in the lineage of Ancylostoma, having a close phylogenetic relationship with A. caninum. This study reports for the first time the mt genome of A. tubaeforme from cats in China, which could enhance the mt genome database of Ancylostomatidae nematodes, and it offers the scientific basis for further studies in the genetic diversity of hookworms among different hosts.
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- Detection and quantification of soil-transmitted helminths in environmental samples: A review of current state-of-the-art and future perspectives. [Review]
- ATActa Trop 2017; 169:187-201
- It is estimated that over a billion people are infected with soil-transmitted helminths (STHs) globally with majority occurring in tropical and subtropical regions of the world. The roundworm (Ascari...
It is estimated that over a billion people are infected with soil-transmitted helminths (STHs) globally with majority occurring in tropical and subtropical regions of the world. The roundworm (Ascaris lumbricoides), whipworm (Trichuris trichiura), and hookworms (Ancylostoma duodenale and Necator americanus) are the main species infecting people. These infections are mostly gained through exposure to faecally contaminated water, soil or contaminated food and with an increase in the risk of infections due to wastewater and sludge reuse in agriculture. Different methods have been developed for the detection and quantification of STHs eggs in environmental samples. However, there is a lack of a universally accepted technique which creates a challenge for comparative assessments of helminths egg concentrations both in different samples matrices as well as between locations. This review presents a comparison of reported methodologies for the detection of STHs eggs, an assessment of the relative performance of available detection methods and a discussion of new emerging techniques that could be applied for detection and quantification. It is based on a literature search using PubMed and Science Direct considering all geographical locations. Original research articles were selected based on their methodology and results sections. Methods reported in these articles were grouped into conventional, molecular and emerging techniques, the main steps in each method were then compared and discussed. The inclusion of a dissociation step aimed at detaching helminth eggs from particulate matter was found to improve the recovery of eggs. Additionally the selection and application of flotation solutions that take into account the relative densities of the eggs of different species of STHs also results in higher egg recovery. Generally the use of conventional methods was shown to be laborious and time consuming and prone to human error. The alternate use of nucleic acid-based techniques has improved the sensitivity of detection and made species specific identification possible. However, these nucleic acid based methods are expensive and less suitable in regions with limited resources and skill. The loop mediated isothermal amplification method shows promise for application in these settings due to its simplicity and use of basic equipment. In addition, the development of imaging soft-ware for the detection and quantification of STHs shows promise to further reduce human error associated with the analysis of environmental samples. It may be concluded that there is a need to comparatively assess the performance of different methods to determine their applicability in different settings as well as for use with different sample matrices (wastewater, sludge, compost, soil, vegetables etc.).