title: SNP genotyping of animal and human derived isolates of Mycobacterium avium subsp. paratuberculosis.
abstract: Mycobacterium avium subsp. paratuberculosis (MAP) is the aetiological agent of Johne's disease (JD), a chronic granulomatous enteritis that affects ruminants worldwide. While the ability of MAP to cause disease in animals is clear, the role of this bacterium in human inflammatory bowel diseases remains unresolved. Previous whole genome sequencing of MAP isolates derived from human and three animal hosts showed that human isolates were genetically similar and showed a close phylogenetic relationship to one bovine isolate. In contrast, other animal derived isolates were more genetically diverse. The present study aimed to investigate the frequency of this human strain across 52 wild-type MAP isolates, collected predominantly from Australia. A Luminex based SNP genotyping approach was utilised to genotype SNPs that had previously been shown to be specific to the human, bovine or ovine isolate types. Fourteen SNPs were initially evaluated across a reference panel of isolates with known genotypes. A subset of seven SNPs was chosen for analysis within the wild-type collection. Of the seven SNPs, three were found to be unique to paediatric human isolates. No wild-type isolates contain these SNP alleles. Interestingly, and in contrast to the paediatric isolates, three additional adult human isolates (derived from adult Crohn's disease patients) also did not contain these SNP alleles. Furthermore we identified two SNPs, which demonstrate extensive polymorphism within the animal-derived MAP isolates. One of which appears unique to ovine and a single camel isolate. From this study we suggest the existence of genetic heterogeneity between human derived MAP isolates, some of which are highly similar to those derived from bovine hosts, but others of which are more divergent.
authors: CSIRO Animal, Food and Health Sciences, Australian Animal Health Laboratory, Geelong 3219, VIC, Australia. Electronic address: james.wynne@csiro.au.
authors: James W
authors: JW
authors: Wynne
authors: CSIRO Animal, Food and Health Sciences, Australian Animal Health Laboratory, Geelong 3219, VIC, Australia; School of Medicine, Deakin University, Waurn Ponds 3216, VIC, Australia.
authors: Christie
authors: C
authors: Beller
authors: CSIRO Animal, Food and Health Sciences, Australian Animal Health Laboratory, Geelong 3219, VIC, Australia.
authors: Victoria
authors: V
authors: Boyd
authors: Department of Agriculture and Food Western Australia, South Perth 6151, WA, Australia.
authors: Barry
authors: B
authors: Francis
authors: Department of Environment and Primary Industries, Attwood 3049, VIC, Australia.
authors: Jacek
authors: J
authors: Gwoźdź
authors: Department of Environment and Primary Industries, Attwood 3049, VIC, Australia.
authors: Marios
authors: M
authors: Carajias
authors: CSIRO Animal, Food and Health Sciences, Australian Animal Health Laboratory, Geelong 3219, VIC, Australia.
authors: Hans G
authors: HG
authors: Heine
authors: Murdoch Children's Research Institute, The Royal Children's Hospital, Parkville 3052, VIC, Australia.
authors: Josef
authors: J
authors: Wagner
authors: Murdoch Children's Research Institute, The Royal Children's Hospital, Parkville 3052, VIC, Australia.
authors: Carl D
authors: CD
authors: Kirkwood
authors: CSIRO Animal, Food and Health Sciences, Australian Animal Health Laboratory, Geelong 3219, VIC, Australia.
authors: Wojtek P
authors: WP
authors: Michalski
mesh_terms: D000818:Animals; D001315:Australia; D002417:Cattle; D005838:Genotype; D006801:Humans; D016927:Mycobacterium avium subsp. paratuberculosis / Q000235:genetics* / Q000302:isolation & purification; D010283:Paratuberculosis / Q000453:epidemiology / Q000382:microbiology*; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide; D012756:Sheep / Q000235:genetics
keywords: Johne's disease; Luminex; Paratuberculosis; Single nucleotide polymorphism