Occurrence of Mycobacterium avium subspecies paratuberculosis across host species and European countries with evidence for transmission between wildlife and domestic ruminants

Abstract

BackgroundMycobacterium avium subspecies paratuberculosis (Map) causes an infectious chronic enteritis (paratuberculosis or Johne's disease) principally of ruminants. The epidemiology of Map is poorly understood, particularly with respect to the role of wildlife reservoirs and the controversial issue of zoonotic potential (Crohn's disease). Genotypic discrimination of Map isolates is pivotal to descriptive epidemiology and resolving these issues. This study was undertaken to determine the genetic diversity of Map, enhance our understanding of the host range and distribution and assess the potential for interspecies transmission.Results164 Map isolates from seven European countries representing 19 different host species were genotyped by standardized IS900 - restriction fragment length polymorphism (IS900-RFLP), pulsed-field gel electrophoresis (PFGE), amplified fragment length polymorphisms (AFLP) and mycobacterial interspersed repeat unit-variable number tandem repeat (MIRU-VNTR) analyses. Six PstI and 17 BstEII IS900-RFLP, 31 multiplex [SnaBI-SpeI] PFGE profiles and 23 MIRU-VNTR profiles were detected. AFLP gave insufficient discrimination of isolates for meaningful genetic analysis. Point estimates for Simpson's index of diversity calculated for the individual typing techniques were in the range of 0.636 to 0.664 but a combination of all three methods increased the discriminating power to 0.879, sufficient for investigating transmission dynamics. Two predominant strain types were detected across Europe with all three typing techniques. Evidence for interspecies transmission between wildlife and domestic ruminants on the same property was demonstrated in four cases, between wildlife species on the same property in two cases and between different species of domestic livestock on one property.ConclusionThe results of this study showed that it is necessary to use multiple genotyping techniques targeting different sources of genetic variation to obtain the level of discrimination necessary to investigate transmission dynamics and trace the source of Map infections. Furthermore, the combination of genotyping techniques may depend on the geographical location of the population to be tested. Identical genotypes were obtained from Map isolated from different host species co-habiting on the same property strongly suggesting that interspecies transmission occurs. Interspecies transmission of Map between wildlife species and domestic livestock on the same property provides further evidence to support a role for wildlife reservoirs of infection.

Mycobacterium avium ssp . paratuberculosis detection in animals, food, water and other sources or vehicles of human exposure: A scoping review of the existing evidence

“…Most of these studies were based on existing isolate collections, and showed a fair amount of homogeneity within M. paratuberculosis strains and revealed that M. paratuberculosis strains from human infections were less diverse compared to cattle (Wynne et al, 2011). Results were derived from several methods making it difficult to make direct comparisons, including IS1311 restriction fragment length polymorphism (RFLP) analyses (Whittington et al, 2000;Motiwala et al, 2003;Singh et al, 2010b;Okuni et al, 2012;Liapi et al, 2015), (Stevenson et al, 2009;Fernandez-Silva et al, 2012) randomly amplified polymorphic DNA (RAPD) (Pillai et al, 2001), multi-locus short sequence repeat sequencing (MLSSR) (Fernandez-Silva et al, 2012), Multiplex PCR of IS900 integration loci (MPIL) (Motiwala et al, 2004), short sequence repeats (SSR) (Ghadiali et al, 2004), and single nucleotide polymorphisms (SNPs) (Wynne et al, 2011). A tally of the type of M. paratuberculosis (e.g.…”

“…cattle, sheep, bison) found by species category is shown in Figure 4. Multiple fingerprinting techniques were used to show the diversity of M. paratuberculosis within populations, and it was argued that it is possible to demonstrate strain sharing within and across species by the degree of homogeneity between isolates (Stevenson et al, 2009 (Singh et al, 2010b;Sohal et al, 2014;Ahlstrom et al, 2015;Podder et al, 2015).…”

Novel Single Nucleotide Polymorphism-Based Assay for Genotyping Mycobacterium avium subsp. paratuberculosis

“…Genetic diversity among M. avium subspecies paratuberculosis strains has been investigated using molecular techniques, such as restriction fragment length polymorphism (RFLP) and IS900 analysis (IS900 RFLP) (3), pulsed-field gel electrophoresis (PFGE) (4), amplified fragment length polymorphism (AFLP) analysis (5), random amplified polymorphic DNA (RAPD) analysis (6), mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR) analysis (7), and short-sequence repeat (SSR) analysis (8). However, these techniques have limited discriminatory power when applied to M. avium subspecies paratuberculosis; although this power can be increased by combining complementary genotyping techniques, it is often insufficient for accurately determining relationships among isolates or global epidemiological studies (9,10).…”

Quantification of Mycobacterium avium subsp. paratuberculosis Strains Representing Distinct Genotypes and Isolated from Domestic and Wildlife Animal Species by Use of an Automatic Liquid Culture System

“…Although the classification of strains into C, S, or B types may reflect a host preference, multiple strains of M. avium subsp. paratuberculosis can cross the species barriers and be isolated from a broad range of animal species (28,29,41). While the diverse M. avium subsp.…”