title: A combination of PhP typing and β-d-glucuronidase gene sequence variation analysis for differentiation of Escherichia coli from humans and animals.
abstract: We investigated the usefulness of the β-d-glucuronidase gene variance in Escherichia coli as a microbial source tracking tool using a novel algorithm for comparison of sequences from a prescreened set of host-specific isolates using a high-resolution PhP typing method. A total of 65 common biochemical phenotypes belonging to 318 E. coli strains isolated from humans and domestic and wild animals were analysed for nucleotide variations at 10 loci along a 518 bp fragment of the 1812 bp β-d-glucuronidase gene. Neighbour-joining analysis of loci variations revealed 86 (76.8%) human isolates and 91.2% of animal isolates were correctly identified. Pairwise hierarchical clustering improved assignment; where 92 (82.1%) human and 204 (99%) animal strains were assigned to their respective cluster. Our data show that initial typing of isolates and selection of common types from different hosts prior to analysis of the β-d-glucuronidase gene sequence improves source identification. We also concluded that numerical profiling of the nucleotide variations can be used as a valuable approach to differentiate human from animal E. coli. This study signifies the usefulness of the β-d-glucuronidase gene as a marker for differentiating human faecal pollution from animal sources.
authors.affiliation: Genecology Research Centre, School of Health and Sports Science, University of the Sunshine Coast, Maroochydore, Queensland, Australia.
authors.forename: N
authors.initials: N
authors.lastname: Masters
authors.forename: M
authors.initials: M
authors.lastname: Christie
authors.forename: M
authors.initials: M
authors.lastname: Katouli
authors.forename: H
authors.initials: H
authors.lastname: Stratton
mesh_terms: D000818:Animals; D000829:Animals, Domestic / Q000382:microbiology; D000835:Animals, Wild / Q000382:microbiology; D015373:Bacterial Typing Techniques / Q000379:methods*; D002417:Cattle; D002645:Chickens; D004285:Dogs; D004926:Escherichia coli / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000382:microbiology* / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D005243:Feces / Q000382:microbiology; D014644:Genetic Variation; D005966:Glucuronidase / Q000235:genetics* / Q000378:metabolism; D006736:Horses; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013552:Swine
chemical_list: D029968:Escherichia coli Proteins; D005966:Glucuronidase
keywords: E. coli; PhP typing; analyse numérique; gène de la β-d-glucuronidase; numerical analysis; typage PhP; β-d-glucuronidase gene