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Rebecca J. Traub - One of the best experts on this subject based on the ideXlab platform.

  • field application of a novel multiplex qpcr assay reveals the occurrence of the zoonotic hookworm Ancylostoma Braziliense in nigerian dogs
    Acta Tropica, 2021
    Co-Authors: Luca Massetti, Joshua Kamani, Anke K Wiethoelter, Phillip Mcdonagh, Vito Colella, Rebecca J. Traub
    Abstract:

    A number of gastrointestinal parasites have been reported to infect dogs in Nigeria, some of which have zoonotic potential. Of these, hookworms are the most prevalent, with both Ancylostoma caninum and Uncinaria stenocephala reported in the country. In this study, we subjected 203 hookworm microscopy-positive samples of the 885 individual faecal samples collected from dogs in Nigeria to a recently developed multiplex qPCR for the detection and characterisation of canine hookworm species. The qPCR demonstrated a diagnostic sensitivity of 98% (95% CI 95-99.4) allowing the detection of A. caninum and A. Braziliense in 81.3% (165/203, 95% CI 75.3-86.1) and 51.2% (104/203, 95% CI 44.4-58) of the microscopy-positive faecal samples of dogs from Nigeria, respectively and 34.5% (70/203, 95% CI 28.3-41.3) of mixed infections with both hookworm species. The finding of A. Braziliense is particularly worrisome given this is a well-known agent of persistent cutaneous larva migrans, commonly referred to as "creeping eruptions" in humans. Although this parasite has been diagnosed in locals and in people travelling in Nigeria suffering from dermatological illnesses, this represents the first molecular identification of A. Braziliense in its canine reservoir in the country. These results update the occurrence and distribution of hookworm species affecting dogs in Nigeria highlighting the suitability of the newly developed multiplex qPCR assay as a high-throughput tool for the surveillance of zoonotic hookworms, globally.

  • RESEARCH Open Access Re-evaluation of the species of hookworms infecting dogs in Central Vietnam
    2016
    Co-Authors: Dinh Ng-nguyen, Sze Fui Hii, Van-anh T Nguyen, Trong Van Nguyen, Dien Van Nguyen, Rebecca J. Traub
    Abstract:

    Background: Differentiation of canine hookworm species is crucial from both a veterinary and public health standpoint. In Vietnam, three hookworm species, namely Ancylostoma caninum, Ancylostoma Braziliense and Uncinaria stenocephala are reported to infect dogs. In light of the emerging distribution of A. ceylanicum in Asia, this study aims to re-evaluate the status of Ancylostoma in dogs in Vietnam. Methods: Faecal samples collected from 200 community dogs in Dak Lak province were subjected to faecal floatation for the detection of hookworm eggs. Hookworm-positive samples were subjected to a PCR-Restriction Fragment Length Polymorphism (PCR-RFLP) assay targeting the internal transcribed spacer (ITS) region of rDNA for hookworm species identification. A subset of hookworm-positive samples was also subject to haplotype characterisation at the cytochrome oxidase-1 (COX-1) gene. Detailed morphological criteria were utilised in addition to molecular markers, to identify adult hookworms recovered from necropsied dogs. Results: Of 200 canine faecal samples, 111 (55.5 %) were positive for hookworm eggs on faecal flotation. Of these, 94/111 (84.7 %) were successfully amplified and assigned species status by PCR-RFLP targeting the ITS region. In total, 54.3 % (51/94) dogs harboured single infections with A. ceylanicum, 33.0 % (31/94) with A. caninum, and 12.7 % (12/94) harboured mixed infections with both A. ceylanicum and A. caninum. Adult worms recovered from necropsied dogs matched morphological description provided for A. ceylanicum, Looss (1911) for which the mediolateral and posteriolateral rays are parallel. Characterisation of the COX-1 gene placed all Vietnamese canine isolates of A. ceylanicum within the ‘zoonotic ’ haplotype. Conclusion: Based on this information, it is apparent that the hookworms present in dogs in Vietnam are those of A. ceylanicum and not A. Braziliense. Owing to the endemic nature of this significant zoonosis in dogs, the study strongly advocates for specific identification of this hookworm in human hookworm surveys

  • re evaluation of the species of hookworms infecting dogs in central vietnam
    Parasites & Vectors, 2015
    Co-Authors: Dinh Ngnguyen, Sze Fui Hii, Trong Van Nguyen, Dien Van Nguyen, Vananh Thi Nguyen, Rebecca J. Traub
    Abstract:

    Differentiation of canine hookworm species is crucial from both a veterinary and public health standpoint. In Vietnam, three hookworm species, namely Ancylostoma caninum, Ancylostoma Braziliense and Uncinaria stenocephala are reported to infect dogs. In light of the emerging distribution of A. ceylanicum in Asia, this study aims to re-evaluate the status of Ancylostoma in dogs in Vietnam. Faecal samples collected from 200 community dogs in Dak Lak province were subjected to faecal floatation for the detection of hookworm eggs. Hookworm-positive samples were subjected to a PCR-Restriction Fragment Length Polymorphism (PCR-RFLP) assay targeting the internal transcribed spacer (ITS) region of rDNA for hookworm species identification. A subset of hookworm-positive samples was also subject to haplotype characterisation at the cytochrome oxidase-1 (COX-1) gene. Detailed morphological criteria were utilised in addition to molecular markers, to identify adult hookworms recovered from necropsied dogs. Of 200 canine faecal samples, 111 (55.5 %) were positive for hookworm eggs on faecal flotation. Of these, 94/111 (84.7 %) were successfully amplified and assigned species status by PCR-RFLP targeting the ITS region. In total, 54.3 % (51/94) dogs harboured single infections with A. ceylanicum, 33.0 % (31/94) with A. caninum, and 12.7 % (12/94) harboured mixed infections with both A. ceylanicum and A. caninum. Adult worms recovered from necropsied dogs matched morphological description provided for A. ceylanicum, Looss (1911) for which the mediolateral and posteriolateral rays are parallel. Characterisation of the COX-1 gene placed all Vietnamese canine isolates of A. ceylanicum within the ‘zoonotic’ haplotype. Based on this information, it is apparent that the hookworms present in dogs in Vietnam are those of A. ceylanicum and not A. Braziliense. Owing to the endemic nature of this significant zoonosis in dogs, the study strongly advocates for specific identification of this hookworm in human hookworm surveys.

  • Re-evaluation of the species of hookworms infecting dogs in Central Vietnam
    Parasites & Vectors, 2015
    Co-Authors: Dinh Ng-nguyen, Sze Fui Hii, Van-anh T Nguyen, Trong Van Nguyen, Dien Van Nguyen, Rebecca J. Traub
    Abstract:

    Background Differentiation of canine hookworm species is crucial from both a veterinary and public health standpoint. In Vietnam, three hookworm species, namely Ancylostoma caninum, Ancylostoma Braziliense and Uncinaria stenocephala are reported to infect dogs. In light of the emerging distribution of A. ceylanicum in Asia, this study aims to re-evaluate the status of Ancylostoma in dogs in Vietnam. Methods Faecal samples collected from 200 community dogs in Dak Lak province were subjected to faecal floatation for the detection of hookworm eggs. Hookworm-positive samples were subjected to a PCR-Restriction Fragment Length Polymorphism (PCR-RFLP) assay targeting the internal transcribed spacer (ITS) region of rDNA for hookworm species identification. A subset of hookworm-positive samples was also subject to haplotype characterisation at the cytochrome oxidase-1 (COX-1) gene. Detailed morphological criteria were utilised in addition to molecular markers, to identify adult hookworms recovered from necropsied dogs. Results Of 200 canine faecal samples, 111 (55.5 %) were positive for hookworm eggs on faecal flotation. Of these, 94/111 (84.7 %) were successfully amplified and assigned species status by PCR-RFLP targeting the ITS region. In total, 54.3 % (51/94) dogs harboured single infections with A. ceylanicum , 33.0 % (31/94) with A. caninum, and 12.7 % (12/94) harboured mixed infections with both A. ceylanicum and A. caninum . Adult worms recovered from necropsied dogs matched morphological description provided for A. ceylanicum , Looss (1911) for which the mediolateral and posteriolateral rays are parallel. Characterisation of the COX-1 gene placed all Vietnamese canine isolates of A. ceylanicum within the ‘zoonotic’ haplotype. Conclusion Based on this information, it is apparent that the hookworms present in dogs in Vietnam are those of A. ceylanicum and not A. Braziliense . Owing to the endemic nature of this significant zoonosis in dogs, the study strongly advocates for specific identification of this hookworm in human hookworm surveys.

  • Epidemiological and Genetic Data Supporting the Transmission of Ancylostoma ceylanicum among Human and Domestic Animals
    PLoS neglected tropical diseases, 2012
    Co-Authors: Romano Ngui, Rebecca J. Traub, Yvonne A. L. Lim, Rohela Mahmud, Mohd Sani Mistam
    Abstract:

    Background: Currently, information on species-specific hookworm infection is unavailable in Malaysia and is restricted worldwide due to limited application of molecular diagnostic tools. Given the importance of accurate identification of hookworms, this study was conducted as part of an ongoing molecular epidemiological investigation aimed at providing the first documented data on species-specific hookworm infection, associated risk factors and the role of domestic animals as reservoirs for hookworm infections in endemic communities of Malaysia. Methods/Findings: A total of 634 human and 105 domestic canine and feline fecal samples were randomly collected. The overall prevalence of hookworm in humans and animals determined via microscopy was 9.1% (95% CI = 7.0-11.7%) and 61.9% (95% CI = 51.2-71.2%), respectively. Multivariate analysis indicated that participants without the provision of proper latrine systems (OR = 3.5; 95% CI = 1.53-8.00; p = 0.003), walking barefooted (OR = 5.6; 95% CI = 2.91-10.73; p&0.001) and in close contact with pets or livestock (OR = 2.9; 95% CI = 1.19-7.15; p = 0.009) were more likely to be infected with hookworms. Molecular analysis revealed that while most hookworm-positive individuals were infected with Necator americanus, Ancylostoma ceylanicum constituted 12.8% of single infections and 10.6% mixed infections with N. americanus. As for cats and dogs, 52.0% were positive for A. ceylanicum, 46.0% for Ancylostoma caninum and 2.0% for Ancylostoma Braziliense and all were single infections. Conclusion: This present study provided evidence based on the combination of epidemiological, conventional diagnostic and molecular tools that A. ceylanicum infection is common and that its transmission dynamic in endemic areas in Malaysia is heightened by the close contact of human and domestic animal (i.e., dogs and cats) populations.

Dwight D Bowman - One of the best experts on this subject based on the ideXlab platform.

  • Efficacy of oral afoxolaner plus milbemycin oxime chewables against induced gastrointestinal nematode infections in dogs
    Veterinary parasitology, 2016
    Co-Authors: Rebecca Fankhauser, Dionne Crafford, Dwight D Bowman, Michael Ulrich, S. Yoon, Dietmar Hamel, Paul M. Dorr, Craig R. Reinemeyer, Diane Larsen
    Abstract:

    The efficacy of oral afoxolaner plus milbemycin oxime combination chewables against induced gastrointestinal nematode infections in dogs was evaluated in six separate studies. Two studies were performed to evaluate the efficacy of the product against Toxocara canis, two studies evaluated the efficacy against Toxascaris leonina, one study evaluated the efficacy against Ancylostoma Braziliense, and one study evaluated the efficacy against Ancylostoma caninum. In the A. caninum study, the efficacy of milbemycin oxime alone and afoxolaner alone was also evaluated. Dogs in all studies were inoculated with infective eggs or larvae and confirmed to have patent infections based on a fecal examination prior to allocation to study group and treatment. Each study utilized a randomized block design with blocks based on pre-treatment body weight. All dogs were assigned to blocks based on body weight, and then each dog within a block was randomly assigned to treatment group. There were two groups of 10 dogs each in the T. canis, T. leonina, and A. Braziliense studies: 1) an untreated (control) group and 2) a group treated with afoxolaner plus milbemycin oxime chewables (NexGard Spectra(®), Merial). This group was treated at a dose as close as possible to the minimum effective dose of afoxolaner and milbemycin oxime (2.5mg+0.5mg per kg body weight, respectively) once on Day 0 using whole chews. There were four groups of 10 dogs each in the A. caninum study: 1) untreated (control), 2) NexGard Spectra(®) as described above, 3) milbemycin oxime alone (dose of at least 0.5mg per kg of body weight) and 4) afoxalaner alone (dose of at least 2.5mg per kg body weight). For parasite recovery and counts, dogs were euthanized humanely and necropsied seven days after treatment. The efficacy of the afoxolaner plus milbemycin oxime combination was ≥98% against T. canis, ≥95.8% against T. leonina, and 90.2% against A. Braziliense. Efficacy of the combination against A. caninum was 99.7%, while the efficacy of milbemycin oxime alone was 99.6% and the efficacy of afoxolaner alone was 2.1%. Dogs treated with afoxolaner plus milbemycin oxime chewables had significantly (p≤0.0002) fewer nematodes than the untreated controls in all studies. There were no adverse events or other health problems that were related to treatment with Nexgard Spectra(®) in these studies. The results of these controlled studies demonstrate the high efficacy of the afoxolaner plus milbemycin oxime chewables against a broad range of canine intestinal nematode infections.

  • efficacy of afoxolaner plus milbemycin oxime chewable tablets against naturally acquired intestinal nematodes in dogs
    Veterinary Parasitology, 2016
    Co-Authors: Steffen Rehbein, Dionne Crafford, Dwight D Bowman, Ilir Kusi, Rezart Postoli, S. Yoon, Paul M. Dorr, Theodore S Chester, Doris Dollhofer, Martin Visser
    Abstract:

    The efficacy of oral afoxolaner plus milbemycin oxime combination chewable tablets (NexGard Spectra, Merial) against naturally acquired intestinal nematode infections in dogs was evaluated in six negative control, blinded studies including a total of 114 dogs. Dogs were selected based on a pre-treatment fecal examination indicating patent infections with hookworms (two studies), Toxocara or Toxascaris ascarids (one study each) or Trichuris whipworms (two studies). In each study, dogs were assigned to blocks of two animals each, based on decreasing pre-treatment body weight and were randomly allocated to one of two groups consisting of eight, nine or 10 dogs: untreated (control) or treated with the combination chewable tablet formulation. Chewable tablets were combined to provide doses of actives as close as possible to the minimum effective dose of afoxolaner and milbemycin oxime, i.e., 2.5 mg/kg body weight and 0.5 mg/kg body weight, respectively, once on Day 0. For parasite recovery and count, dogs were euthanized humanely and necropsied seven or eight days after treatment. A single treatment with afoxolaner plus milbemycin oxime chewable tablets provided 94.8% and 90.9% efficacy against adult Ancylostoma Braziliense and A. caninum, respectively, 97.8% and 99.4% efficacy against adult Toxocara canis and Toxascaris leonina, respectively, and ≥98.3% efficacy against adult Trichuris vulpis. Compared to untreated controls, nematode counts of the treated dogs were significantly reduced (F-test; p<0.002). In addition, analysis of the pooled data across studies revealed that treatment with afoxolaner plus milbemycin oxime chewable tablets reduced adult Uncinaria stenocephala burdens by 74.9% (p=0.002). All dogs tolerated the treatment well based on clinical observations post-treatment and daily clinical observations. No adverse experiences or other clinical problems related to the treatment were observed throughout the studies. The results of this series of controlled studies demonstrated high efficacy and excellent acceptability and safety of the afoxolaner plus milbemycin oxime chewable tablets when administered for treatment of a broad range of canine intestinal nematode infections.

  • Efficacy of a novel topical combination of fipronil, (S)-methoprene, eprinomectin and praziquantel against induced infections of Ancylostoma spp. nematodes of cats.
    Veterinary Parasitology, 2014
    Co-Authors: Joseph B Prullage, Dwight D Bowman, Martin Knaus, Martin Visser, S Theodore Chester, Joseph Rosentel
    Abstract:

    Four studies were conducted to examine the efficacy of a novel topical combination of fipronil, (S)-methoprene, eprinomectin, and praziquantel (BROADLINE(®), Merial) against Ancylostoma tubaeforme and Ancylostoma Braziliense hookworms of cats. In each study, purpose-bred cats were randomly assigned to treatment groups of 10 or 12 cats per group. In three studies the cats were inoculated with A. tubaeforme and in one study with A. Braziliense. The inoculations were undertaken on a schedule which resulted in the hookworms reaching the fourth larval stage in two of the studies, or the adult stage in four of the studies, by the day of treatment. In each study there was also an untreated control and 1 or 2 groups treated with the novel combination. In the two studies where efficacy against the fourth larval stage of A. tubaeforme was tested, the efficacy recorded was 100%. In the three studies where efficacy against the adult stage of A. tubaeforme was tested, efficacy of 100% was also confirmed. In the study where efficacy against the adult stage of A. Braziliense was tested efficacy was 99.5%.

  • prevalence of Ancylostoma Braziliense in dogs from alachua and marion counties florida united states
    Journal of Parasitology, 2012
    Co-Authors: Janice L Liotta, Stephen E. Bienhoff, Heejeong Youn, Sarp Aksel, Dwight D Bowman
    Abstract:

    A convenience collection of fecal samples from 148 dogs in northern Florida was examined for the presence of Ancylostoma Braziliense eggs by using centrifugal sugar flotation and polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). Of the 148 samples, 64 (43.2%) contained hookworm eggs. DNA from 42 samples was successfully amplified using PCR; using RFLP, 2 samples were identified as containing DNA of A. Braziliense (4.8% of the 42 successfully amplified samples).

  • Morphological differentiation of eggs of Ancylostoma caninum, Ancylostoma tubaeforme, and Ancylostoma Braziliense from dogs and cats in the United States.
    Journal of Parasitology, 2012
    Co-Authors: Araceli Lucio-forster, Janice L Liotta, Joseph P. Yaros, Kaitlyn R. Briggs, Hussni O. Mohammed, Dwight D Bowman
    Abstract:

    Abstract: The establishment of cat- and dog-derived laboratory strains of Ancylostoma Braziliense allowed for a morphological comparison of the eggs of A. Braziliense, Ancylostoma caninum, and Ancylostoma tubaeforme. The length, width, and perimeter were determined for images of 10 eggs each of A. Braziliense from the feces of a dog infected with a canine isolate and a cat infected with a feline isolate, A. caninum from dog feces, and A. tubaeforme from cat feces. The specific identity of the eggs was verified by polymerase chain reaction and restriction fragment length polymorphism by using HinfI and RsaI restriction digests followed by gel electrophoresis and sequencing. The mean (±SD) length, width, and perimeter and the length-to-width ratio (±SD) (all measurements are in micrometers) for the eggs of each species were as follows: A. Braziliense eggs (combined cat and dog source), 53.03 ± 2.33, 36.37 ± 1.35, 140.43 ± 2.56, and 1.46 ± 0.11; A. caninum eggs, 63.92 ± 5.28, 39.21 ± 1.52, 161.99 ± 9.30, and...

Romano Ngui - One of the best experts on this subject based on the ideXlab platform.

  • Rapid detection and identification of human hookworm infections through high resolution melting (HRM) analysis. PLoS One
    2016
    Co-Authors: Romano Ngui, Yvonne A. L. Lim, Kek Heng Chua
    Abstract:

    Background: Hookworm infections are still endemic in low and middle income tropical countries with greater impact on the socioeconomic and public health of the bottom billion of the world’s poorest people. In this study, a real-time polymerase chain reaction (PCR) coupled with high resolution melting-curve (HRM) analysis was evaluated for an accurate, rapid and sensitive tool for species identification focusing on the five human hookworm species. Methods: Real-time PCR coupled with HRM analysis targeting the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA as the genetic marker was used to identify and distinguish hookworm species in human samples. Unique and distinct characteristics of HRM patterns were produced for each of the five hookworm species. The melting curves were characterized by peaks of 79.2460.05uC and 83.0060.04uC for Necator americanus, 79.1260.10uC for Ancylostoma duodenale, 79.4060.10uC for Ancylostoma ceylanicum, 79.6360.05uC for Ancylostoma caninum and 79.7060.14uC for Ancylostoma Braziliense. An evaluation of the method’s sensitivity and specificity revealed that this assay was able to detect as low as 0.01 ng/ml hookworm DNA and amplification was only recorded for hookworm positive samples. Conclusion: The HRM assay developed in this study is a rapid and straightforward method for the diagnosis, identification and discrimination of five human hookworms. This assay is simple compared to other probe-based genotyping methods as it does not require multiplexing, DNA sequencing or post-PCR processing. Therefore, this method offers a new alternativ

  • rapid detection and identification of human hookworm infections through high resolution melting hrm analysis
    PLOS ONE, 2012
    Co-Authors: Romano Ngui, Yvonne A. L. Lim, Kek Heng Chua
    Abstract:

    Background Hookworm infections are still endemic in low and middle income tropical countries with greater impact on the socioeconomic and public health of the bottom billion of the world's poorest people. In this study, a real-time polymerase chain reaction (PCR) coupled with high resolution melting-curve (HRM) analysis was evaluated for an accurate, rapid and sensitive tool for species identification focusing on the five human hookworm species. Methods Real-time PCR coupled with HRM analysis targeting the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA as the genetic marker was used to identify and distinguish hookworm species in human samples. Unique and distinct characteristics of HRM patterns were produced for each of the five hookworm species. The melting curves were characterized by peaks of 79.24±0.05°C and 83.00±0.04°C for Necator americanus, 79.12±0.10°C for Ancylostoma duodenale, 79.40±0.10°C for Ancylostoma ceylanicum, 79.63±0.05°C for Ancylostoma caninum and 79.70±0.14°C for Ancylostoma Braziliense. An evaluation of the method's sensitivity and specificity revealed that this assay was able to detect as low as 0.01 ng/µl hookworm DNA and amplification was only recorded for hookworm positive samples. Conclusion The HRM assay developed in this study is a rapid and straightforward method for the diagnosis, identification and discrimination of five human hookworms. This assay is simple compared to other probe-based genotyping methods as it does not require multiplexing, DNA sequencing or post-PCR processing. Therefore, this method offers a new alternative for rapid detection of human hookworm species.

  • Epidemiological and Genetic Data Supporting the Transmission of Ancylostoma ceylanicum among Human and Domestic Animals
    PLoS neglected tropical diseases, 2012
    Co-Authors: Romano Ngui, Rebecca J. Traub, Yvonne A. L. Lim, Rohela Mahmud, Mohd Sani Mistam
    Abstract:

    Background: Currently, information on species-specific hookworm infection is unavailable in Malaysia and is restricted worldwide due to limited application of molecular diagnostic tools. Given the importance of accurate identification of hookworms, this study was conducted as part of an ongoing molecular epidemiological investigation aimed at providing the first documented data on species-specific hookworm infection, associated risk factors and the role of domestic animals as reservoirs for hookworm infections in endemic communities of Malaysia. Methods/Findings: A total of 634 human and 105 domestic canine and feline fecal samples were randomly collected. The overall prevalence of hookworm in humans and animals determined via microscopy was 9.1% (95% CI = 7.0-11.7%) and 61.9% (95% CI = 51.2-71.2%), respectively. Multivariate analysis indicated that participants without the provision of proper latrine systems (OR = 3.5; 95% CI = 1.53-8.00; p = 0.003), walking barefooted (OR = 5.6; 95% CI = 2.91-10.73; p&0.001) and in close contact with pets or livestock (OR = 2.9; 95% CI = 1.19-7.15; p = 0.009) were more likely to be infected with hookworms. Molecular analysis revealed that while most hookworm-positive individuals were infected with Necator americanus, Ancylostoma ceylanicum constituted 12.8% of single infections and 10.6% mixed infections with N. americanus. As for cats and dogs, 52.0% were positive for A. ceylanicum, 46.0% for Ancylostoma caninum and 2.0% for Ancylostoma Braziliense and all were single infections. Conclusion: This present study provided evidence based on the combination of epidemiological, conventional diagnostic and molecular tools that A. ceylanicum infection is common and that its transmission dynamic in endemic areas in Malaysia is heightened by the close contact of human and domestic animal (i.e., dogs and cats) populations.

Kek Heng Chua - One of the best experts on this subject based on the ideXlab platform.

  • Rapid detection and identification of human hookworm infections through high resolution melting (HRM) analysis. PLoS One
    2016
    Co-Authors: Romano Ngui, Yvonne A. L. Lim, Kek Heng Chua
    Abstract:

    Background: Hookworm infections are still endemic in low and middle income tropical countries with greater impact on the socioeconomic and public health of the bottom billion of the world’s poorest people. In this study, a real-time polymerase chain reaction (PCR) coupled with high resolution melting-curve (HRM) analysis was evaluated for an accurate, rapid and sensitive tool for species identification focusing on the five human hookworm species. Methods: Real-time PCR coupled with HRM analysis targeting the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA as the genetic marker was used to identify and distinguish hookworm species in human samples. Unique and distinct characteristics of HRM patterns were produced for each of the five hookworm species. The melting curves were characterized by peaks of 79.2460.05uC and 83.0060.04uC for Necator americanus, 79.1260.10uC for Ancylostoma duodenale, 79.4060.10uC for Ancylostoma ceylanicum, 79.6360.05uC for Ancylostoma caninum and 79.7060.14uC for Ancylostoma Braziliense. An evaluation of the method’s sensitivity and specificity revealed that this assay was able to detect as low as 0.01 ng/ml hookworm DNA and amplification was only recorded for hookworm positive samples. Conclusion: The HRM assay developed in this study is a rapid and straightforward method for the diagnosis, identification and discrimination of five human hookworms. This assay is simple compared to other probe-based genotyping methods as it does not require multiplexing, DNA sequencing or post-PCR processing. Therefore, this method offers a new alternativ

  • rapid detection and identification of human hookworm infections through high resolution melting hrm analysis
    PLOS ONE, 2012
    Co-Authors: Romano Ngui, Yvonne A. L. Lim, Kek Heng Chua
    Abstract:

    Background Hookworm infections are still endemic in low and middle income tropical countries with greater impact on the socioeconomic and public health of the bottom billion of the world's poorest people. In this study, a real-time polymerase chain reaction (PCR) coupled with high resolution melting-curve (HRM) analysis was evaluated for an accurate, rapid and sensitive tool for species identification focusing on the five human hookworm species. Methods Real-time PCR coupled with HRM analysis targeting the second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA as the genetic marker was used to identify and distinguish hookworm species in human samples. Unique and distinct characteristics of HRM patterns were produced for each of the five hookworm species. The melting curves were characterized by peaks of 79.24±0.05°C and 83.00±0.04°C for Necator americanus, 79.12±0.10°C for Ancylostoma duodenale, 79.40±0.10°C for Ancylostoma ceylanicum, 79.63±0.05°C for Ancylostoma caninum and 79.70±0.14°C for Ancylostoma Braziliense. An evaluation of the method's sensitivity and specificity revealed that this assay was able to detect as low as 0.01 ng/µl hookworm DNA and amplification was only recorded for hookworm positive samples. Conclusion The HRM assay developed in this study is a rapid and straightforward method for the diagnosis, identification and discrimination of five human hookworms. This assay is simple compared to other probe-based genotyping methods as it does not require multiplexing, DNA sequencing or post-PCR processing. Therefore, this method offers a new alternative for rapid detection of human hookworm species.

Eric Caumes - One of the best experts on this subject based on the ideXlab platform.

  • molecular characterization of Ancylostoma Braziliense larvae in a patient with hookworm related cutaneous larva migrans
    American Journal of Tropical Medicine and Hygiene, 2012
    Co-Authors: Alexandre Le Joncour, Sandrine A Lacour, Gabriel Lecso, Stephanie Regnier, Jacques Guillot, Eric Caumes
    Abstract:

    We report a case of hookworm-related cutaneous larva migrans diagnosed microscopically. Viable hookworm larvae were found by microscopic examination of a skin scraping from follicular lesions. Amplification and sequencing of the internal transcribed spacer 2 allowed the specific identification of the larvae as Ancylostoma Braziliense.

  • Efficacy of Ivermectin in the Therapy of Cutaneous Larva Migrans
    Archives of dermatology, 1992
    Co-Authors: Eric Caumes, Annick Datry, L. Paris, Martin Danis, Marc Gentilini, P. Gaxotte
    Abstract:

    To the Editor.— Cutaneous larva migrans (creeping eruption) is a chronic serpiginous cutaneous eruption caused by penetration of the skin by infective larvae of animal hookworms (usually Ancylostoma Braziliense ). Spontaneous migration of larvae usually continues for several weeks and may veryrarely persist for up to a year. Recommended therapy is tiabendazole (orally or topically). 1 It has recently been reported that oral albendazole shows excellent efficacy. 2-4 We report our experience with oral ivermectin, the current drug of choice for treating onchocerciasis. 5 Patients and Methods.— Since December 1, 1990, all patients with cutaneous larva migrans have been treated with a single 12-mg oral dose (200 μg/kg) of ivermectin in an open prospective study. Twelve patients have been enrolled (Table). They had returned from the Caribbean, West Africa, Thailand, Burundi, or the Gulf of Mexico. In four patients, the creeping eruption appeared during their stay abroad. In the others, the lag time between return and the onset of