Reliability of molecular host-identification methods for ticks: an experimental in vitro study with Ixodes ricinus
Abstract Background Reliable information on host use by arthropod vectors is required to study pathogen transmission ecology and to predict disease risk. Direct observation of host use is often difficult or impossible and indirect methods are therefore necessary. However, the reliability of currentl...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2015-08-01
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| Series: | Parasites & Vectors |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s13071-015-1043-7 |
| _version_ | 1827933682336268288 |
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| author | Elsa Léger Xiangye Liu Sébastien Masseglia Valérie Noël Gwenaël Vourc’h Sarah Bonnet Karen D. McCoy |
| author_facet | Elsa Léger Xiangye Liu Sébastien Masseglia Valérie Noël Gwenaël Vourc’h Sarah Bonnet Karen D. McCoy |
| author_sort | Elsa Léger |
| collection | DOAJ |
| description | Abstract Background Reliable information on host use by arthropod vectors is required to study pathogen transmission ecology and to predict disease risk. Direct observation of host use is often difficult or impossible and indirect methods are therefore necessary. However, the reliability of currently available methods to identify the last host of blood-feeding arthropods has not been evaluated, and may be particularly problematic for ticks because host blood has been digested at capture. Biases in host detection may lead to erroneous conclusions on both vector ecology and pathogen circulation. Methods Here, we experimentally tested for biases in host detection using the generalist three-host tick Ixodes ricinus as a model system. We fed ticks using an artificial feeding system and amplified blood meal traces post-moult (i.e., in the succeeding unfed life stage) via both a quantitative real-time polymerase chain reaction assay and a reverse line blotting method. We then experimentally tested for three types of biases in host detection: 1) time post-moult, 2) tick life stage and 3) host type (non-nucleated mammal blood versus nucleated avian blood), and compared these biases between the two molecular methods. Results Our results show that all three factors can influence host detection in ticks but not necessarily in the expected way. Although host detection rates decreased with time post-moult, mammal blood tended to be more readily detected than bird blood. Tick life stage was also an important factor; detection was higher in nymphs than in adults and, in some cases, remnants from both larval and nymphal blood meals could be detected in the adult stage. These biases were similar for the two detection techniques. Conclusions We show that different factors associated with questing ticks may influence our ability to correctly infer previous host use and that these factors may bias inferences from field-based studies. As these biases may be common to other vector-borne disease systems, their implications for our understanding of vector ecology and disease transmission require more explicit consideration. |
| first_indexed | 2024-03-13T07:29:11Z |
| format | Article |
| id | doaj.art-2a105e9489cd4297884e7339e7b95557 |
| institution | Directory Open Access Journal |
| issn | 1756-3305 |
| language | English |
| last_indexed | 2024-03-13T07:29:11Z |
| publishDate | 2015-08-01 |
| publisher | BMC |
| record_format | Article |
| series | Parasites & Vectors |
| spelling | doaj.art-2a105e9489cd4297884e7339e7b955572023-06-04T11:12:43ZengBMCParasites & Vectors1756-33052015-08-018111010.1186/s13071-015-1043-7Reliability of molecular host-identification methods for ticks: an experimental in vitro study with Ixodes ricinusElsa Léger0Xiangye Liu1Sébastien Masseglia2Valérie Noël3Gwenaël Vourc’h4Sarah Bonnet5Karen D. McCoy6MIVEGEC (UMR UM2-UM1-CNRS 5290, UR IRD 224), Centre IRDUSC INRA Bartonella-tiques, UMR BIPAR ENVA-ANSESUnité Epidémiologie Animale (UR INRA 346), Centre de recherche INRA de Clermont-Ferrand / TheixMIVEGEC (UMR UM2-UM1-CNRS 5290, UR IRD 224), Centre IRDUnité Epidémiologie Animale (UR INRA 346), Centre de recherche INRA de Clermont-Ferrand / TheixUSC INRA Bartonella-tiques, UMR BIPAR ENVA-ANSESMIVEGEC (UMR UM2-UM1-CNRS 5290, UR IRD 224), Centre IRDAbstract Background Reliable information on host use by arthropod vectors is required to study pathogen transmission ecology and to predict disease risk. Direct observation of host use is often difficult or impossible and indirect methods are therefore necessary. However, the reliability of currently available methods to identify the last host of blood-feeding arthropods has not been evaluated, and may be particularly problematic for ticks because host blood has been digested at capture. Biases in host detection may lead to erroneous conclusions on both vector ecology and pathogen circulation. Methods Here, we experimentally tested for biases in host detection using the generalist three-host tick Ixodes ricinus as a model system. We fed ticks using an artificial feeding system and amplified blood meal traces post-moult (i.e., in the succeeding unfed life stage) via both a quantitative real-time polymerase chain reaction assay and a reverse line blotting method. We then experimentally tested for three types of biases in host detection: 1) time post-moult, 2) tick life stage and 3) host type (non-nucleated mammal blood versus nucleated avian blood), and compared these biases between the two molecular methods. Results Our results show that all three factors can influence host detection in ticks but not necessarily in the expected way. Although host detection rates decreased with time post-moult, mammal blood tended to be more readily detected than bird blood. Tick life stage was also an important factor; detection was higher in nymphs than in adults and, in some cases, remnants from both larval and nymphal blood meals could be detected in the adult stage. These biases were similar for the two detection techniques. Conclusions We show that different factors associated with questing ticks may influence our ability to correctly infer previous host use and that these factors may bias inferences from field-based studies. As these biases may be common to other vector-borne disease systems, their implications for our understanding of vector ecology and disease transmission require more explicit consideration.https://doi.org/10.1186/s13071-015-1043-7Host identificationHematophagous arthropodsIxodidaeMolecular methodsDetection biasesVector-borne diseases |
| spellingShingle | Elsa Léger Xiangye Liu Sébastien Masseglia Valérie Noël Gwenaël Vourc’h Sarah Bonnet Karen D. McCoy Reliability of molecular host-identification methods for ticks: an experimental in vitro study with Ixodes ricinus Parasites & Vectors Host identification Hematophagous arthropods Ixodidae Molecular methods Detection biases Vector-borne diseases |
| title | Reliability of molecular host-identification methods for ticks: an experimental in vitro study with Ixodes ricinus |
| title_full | Reliability of molecular host-identification methods for ticks: an experimental in vitro study with Ixodes ricinus |
| title_fullStr | Reliability of molecular host-identification methods for ticks: an experimental in vitro study with Ixodes ricinus |
| title_full_unstemmed | Reliability of molecular host-identification methods for ticks: an experimental in vitro study with Ixodes ricinus |
| title_short | Reliability of molecular host-identification methods for ticks: an experimental in vitro study with Ixodes ricinus |
| title_sort | reliability of molecular host identification methods for ticks an experimental in vitro study with ixodes ricinus |
| topic | Host identification Hematophagous arthropods Ixodidae Molecular methods Detection biases Vector-borne diseases |
| url | https://doi.org/10.1186/s13071-015-1043-7 |
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