Suitability of current typing procedures to identify epidemiologically linked human Giardia duodenalis isolates

作者：Andreas Woschke, Mirko Faber, Klaus Stark, Martha Holtfreter, Frank P. Mockenhaupt, Joachim Richter, Thomas Regnath, Ingo Sobottka, Ingrid Reiter‐Owona, Andreas Diefenbach, Petra Gosten-Heinrich, Johannes Friesen, Ralf Ignatius, Toni Aebischer, Christian Klotz · 发表于：PLoS neglected tropical diseases · 年份：2021 · DOI：10.1371/journal.pntd.0009277 · 被引用次数：36 · 研究领域：Parasitic Infections and Diagnostics、Amoebic Infections and Treatments、Parasites and Host Interactions

BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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 ge...