Suitability of current typing procedures to identify epidemiologically linked human Giardia duodenalis isolates.
<h4>Background</h4>Giardia duodenalis is a leading cause of gastroenteritis worldwide. Humans are mainly infected by two different subtypes, i.e., assemblage A and B. Genotyping is hampered by allelic sequence heterozygosity (ASH) mainly in assemblage B, and by occurrence of mixed infect...
Saved in:
| Main Authors: | , , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2021-03-01
|
| Series: | PLoS Neglected Tropical Diseases |
| Online Access: | https://journals.plos.org/plosntds/article/file?id=10.1371/journal.pntd.0009277&type=printable |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850046359256694784 |
|---|---|
| author | Andreas Woschke Mirko Faber Klaus Stark Martha Holtfreter Frank Mockenhaupt Joachim Richter Thomas Regnath Ingo Sobottka Ingrid Reiter-Owona Andreas Diefenbach Petra Gosten-Heinrich Johannes Friesen Ralf Ignatius Toni Aebischer Christian Klotz |
| author_facet | Andreas Woschke Mirko Faber Klaus Stark Martha Holtfreter Frank Mockenhaupt Joachim Richter Thomas Regnath Ingo Sobottka Ingrid Reiter-Owona Andreas Diefenbach Petra Gosten-Heinrich Johannes Friesen Ralf Ignatius Toni Aebischer Christian Klotz |
| author_sort | Andreas Woschke |
| collection | DOAJ |
| description | <h4>Background</h4>Giardia duodenalis is a leading cause of gastroenteritis worldwide. Humans are mainly infected by two different subtypes, i.e., assemblage A and B. Genotyping is hampered by allelic sequence heterozygosity (ASH) mainly in assemblage B, and by occurrence of mixed infections. Here we assessed the suitability of current genotyping protocols of G. duodenalis for epidemiological applications such as molecular tracing of transmission chains.<h4>Methodology/principal findings</h4>Two G. duodenalis isolate collections, from an outpatient tropical medicine clinic and from several primary care laboratories, were characterized by assemblage-specific qPCR (TIF, CATH gene loci) and a common multi locus sequence typing (MLST; TPI, BG, GDH gene loci). Assemblage A isolates were further typed at additional loci (HCMP22547, CID1, RHP26, HCMP6372, DIS3, NEK15411). Of 175/202 (86.6%) patients the G. duodenalis assemblage could be identified: Assemblages A 25/175 (14.3%), B 115/175 (65.7%) and A+B mixed 35/175 (20.0%). By incorporating allelic sequence heterozygosity in the analysis, the three marker MLST correctly identified 6/9 (66,7%) and 4/5 (80.0%) consecutive samples from chronic assemblage B infections in the two collections, respectively, and identified a cluster of five independent patients carrying assemblage B parasites of identical MLST type. Extended MLST for assemblage A altogether identified 5/6 (83,3%) consecutive samples from chronic assemblage A infections and 15 novel genotypes. Based on the observed A+B mixed infections it is estimated that only 75% and 50% of assemblage A or B only cases represent single strain infections, respectively. We demonstrate that typing results are consistent with this prediction.<h4>Conclusions/significance</h4>Typing of assemblage A and B isolates with resolution for epidemiological applications is possible but requires separate genotyping protocols. The high frequency of multiple infections and their impact on typing results are findings with immediate consequences for result interpretation in this field. |
| format | Article |
| id | doaj-art-96f2d29ff7d34e51b8a38ef0a7f29053 |
| institution | DOAJ |
| issn | 1935-2727 1935-2735 |
| language | English |
| publishDate | 2021-03-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Neglected Tropical Diseases |
| spelling | doaj-art-96f2d29ff7d34e51b8a38ef0a7f290532025-08-20T02:54:29ZengPublic Library of Science (PLoS)PLoS Neglected Tropical Diseases1935-27271935-27352021-03-01153e000927710.1371/journal.pntd.0009277Suitability of current typing procedures to identify epidemiologically linked human Giardia duodenalis isolates.Andreas WoschkeMirko FaberKlaus StarkMartha HoltfreterFrank MockenhauptJoachim RichterThomas RegnathIngo SobottkaIngrid Reiter-OwonaAndreas DiefenbachPetra Gosten-HeinrichJohannes FriesenRalf IgnatiusToni AebischerChristian Klotz<h4>Background</h4>Giardia duodenalis is a leading cause of gastroenteritis worldwide. Humans are mainly infected by two different subtypes, i.e., assemblage A and B. Genotyping is hampered by allelic sequence heterozygosity (ASH) mainly in assemblage B, and by occurrence of mixed infections. Here we assessed the suitability of current genotyping protocols of G. duodenalis for epidemiological applications such as molecular tracing of transmission chains.<h4>Methodology/principal findings</h4>Two G. duodenalis isolate collections, from an outpatient tropical medicine clinic and from several primary care laboratories, were characterized by assemblage-specific qPCR (TIF, CATH gene loci) and a common multi locus sequence typing (MLST; TPI, BG, GDH gene loci). Assemblage A isolates were further typed at additional loci (HCMP22547, CID1, RHP26, HCMP6372, DIS3, NEK15411). Of 175/202 (86.6%) patients the G. duodenalis assemblage could be identified: Assemblages A 25/175 (14.3%), B 115/175 (65.7%) and A+B mixed 35/175 (20.0%). By incorporating allelic sequence heterozygosity in the analysis, the three marker MLST correctly identified 6/9 (66,7%) and 4/5 (80.0%) consecutive samples from chronic assemblage B infections in the two collections, respectively, and identified a cluster of five independent patients carrying assemblage B parasites of identical MLST type. Extended MLST for assemblage A altogether identified 5/6 (83,3%) consecutive samples from chronic assemblage A infections and 15 novel genotypes. Based on the observed A+B mixed infections it is estimated that only 75% and 50% of assemblage A or B only cases represent single strain infections, respectively. We demonstrate that typing results are consistent with this prediction.<h4>Conclusions/significance</h4>Typing of assemblage A and B isolates with resolution for epidemiological applications is possible but requires separate genotyping protocols. The high frequency of multiple infections and their impact on typing results are findings with immediate consequences for result interpretation in this field.https://journals.plos.org/plosntds/article/file?id=10.1371/journal.pntd.0009277&type=printable |
| spellingShingle | Andreas Woschke Mirko Faber Klaus Stark Martha Holtfreter Frank Mockenhaupt Joachim Richter Thomas Regnath Ingo Sobottka Ingrid Reiter-Owona Andreas Diefenbach Petra Gosten-Heinrich Johannes Friesen Ralf Ignatius Toni Aebischer Christian Klotz Suitability of current typing procedures to identify epidemiologically linked human Giardia duodenalis isolates. PLoS Neglected Tropical Diseases |
| title | Suitability of current typing procedures to identify epidemiologically linked human Giardia duodenalis isolates. |
| title_full | Suitability of current typing procedures to identify epidemiologically linked human Giardia duodenalis isolates. |
| title_fullStr | Suitability of current typing procedures to identify epidemiologically linked human Giardia duodenalis isolates. |
| title_full_unstemmed | Suitability of current typing procedures to identify epidemiologically linked human Giardia duodenalis isolates. |
| title_short | Suitability of current typing procedures to identify epidemiologically linked human Giardia duodenalis isolates. |
| title_sort | suitability of current typing procedures to identify epidemiologically linked human giardia duodenalis isolates |
| url | https://journals.plos.org/plosntds/article/file?id=10.1371/journal.pntd.0009277&type=printable |
| work_keys_str_mv | AT andreaswoschke suitabilityofcurrenttypingprocedurestoidentifyepidemiologicallylinkedhumangiardiaduodenalisisolates AT mirkofaber suitabilityofcurrenttypingprocedurestoidentifyepidemiologicallylinkedhumangiardiaduodenalisisolates AT klausstark suitabilityofcurrenttypingprocedurestoidentifyepidemiologicallylinkedhumangiardiaduodenalisisolates AT marthaholtfreter suitabilityofcurrenttypingprocedurestoidentifyepidemiologicallylinkedhumangiardiaduodenalisisolates AT frankmockenhaupt suitabilityofcurrenttypingprocedurestoidentifyepidemiologicallylinkedhumangiardiaduodenalisisolates AT joachimrichter suitabilityofcurrenttypingprocedurestoidentifyepidemiologicallylinkedhumangiardiaduodenalisisolates AT thomasregnath suitabilityofcurrenttypingprocedurestoidentifyepidemiologicallylinkedhumangiardiaduodenalisisolates AT ingosobottka suitabilityofcurrenttypingprocedurestoidentifyepidemiologicallylinkedhumangiardiaduodenalisisolates AT ingridreiterowona suitabilityofcurrenttypingprocedurestoidentifyepidemiologicallylinkedhumangiardiaduodenalisisolates AT andreasdiefenbach suitabilityofcurrenttypingprocedurestoidentifyepidemiologicallylinkedhumangiardiaduodenalisisolates AT petragostenheinrich suitabilityofcurrenttypingprocedurestoidentifyepidemiologicallylinkedhumangiardiaduodenalisisolates AT johannesfriesen suitabilityofcurrenttypingprocedurestoidentifyepidemiologicallylinkedhumangiardiaduodenalisisolates AT ralfignatius suitabilityofcurrenttypingprocedurestoidentifyepidemiologicallylinkedhumangiardiaduodenalisisolates AT toniaebischer suitabilityofcurrenttypingprocedurestoidentifyepidemiologicallylinkedhumangiardiaduodenalisisolates AT christianklotz suitabilityofcurrenttypingprocedurestoidentifyepidemiologicallylinkedhumangiardiaduodenalisisolates |