Exploring the Zoonotic Potential of Mycobacterium avium Subspecies paratuberculosis through Comparative Genomics

A comparative genomics approach was utilised to compare the genomes of Mycobacterium avium subspecies paratuberculosis (MAP) isolated from early onset paediatric Crohn's disease (CD) patients as well as Johne's diseased animals. Draft genome sequences were produced for MAP isolates derived from four CD patients, one ulcerative colitis (UC) patient, and two non-inflammatory bowel disease (IBD) control individuals using Illumina sequencing, complemented by comparative genome hybridisation (CGH). MAP isolates derived from two bovine and one ovine host were also subjected to whole genome sequencing and CGH. All seven human derived MAP isolates were highly genetically similar and clustered together with one bovine type isolate following phylogenetic analysis. Three other sequenced isolates (including the reference bovine derived isolate K10) were genetically distinct. The human isolates contained two large tandem duplications, the organisations of which were confirmed by PCR. Designated vGI-17 and vGI-18 these duplications spanned 63 and 109 open reading frames, respectively. PCR screening of over 30 additional MAP isolates (3 human derived, 27 animal derived and one environmental isolate) confirmed that vGI-17 and vGI-18 are common across many isolates. Quantitative real-time PCR of vGI-17 demonstrated that the proportion of cells containing the vGI-17 duplication varied between 0.01 to 15% amongst isolates with human isolates containing a higher proportion of vGI-17 compared to most animal isolates. These findings suggest these duplications are transient genomic rearrangements. We hypothesise that the over-representation of vGI-17 in human derived MAP strains may enhance their ability to infect or persist within a human host by increasing genome redundancy and conferring crude regulation of protein expression across biologically important regions

Survival of listeria monocytogenes and Escherichia coli O157 : H7 during Sauerkraut fermentation

Sauerkraut was produced from shredded cabbage, as is typical in the United States, and from whole head cabbages, which is a traditional process in parts of Eastern Europe. The sauerkraut was inoculated with five strain mixtures of Escherichia coli O157:H7 and Listeria monocytogenes, and the populations of these bacteria, as well as lactic acid bacteria, pH, and titratable acidity, were monitored over the course of fermentation. Fermentation variables were temperature (18 and 22 degrees C) and salt concentration (1.8, 2.25, and 3%). For most of the analyses, the type of cabbage processing was a significant factor, although within cabbage type, neither salt nor fermentation temperature had significant effects. The final pH of the whole-head sauerkraut was lower than the shredded sauerkraut, but the titratable acidity was significantly higher in the shredded sauerkraut. E. coli O157:H7 and L. monocytogenes persisted in the brines for most of the fermentation, although at the end of the fermentations (15 days for shredded, 28 days for whole head), neither pathogen had detectable populations. E. coli populations decreased more rapidly in the shredded sauerkraut even though the pH was higher because of the higher total acidity in the shredded sauerkraut. Acid-tolerant strains of E. coli and L monocytogenes were isolated from both shredded and whole-head sauerkraut at different salt concentrations and temperatures after 15 days of fermentation and could be detected at 35 days in the whole-head sauerkraut

A 60-day probiotic protocol with Dietzia subsp. C79793-74 prevents development of Johne's disease parameters after in utero and/or neonatal MAP infection

The research reported herein was designed to assess whether the bacterium, Dietzia subspecies C79793-74, used as a probiotic, could prevent development of parameters indicative of bovine paratuberculosis after potential in utero, birthing and neonatal (colostrum) exposure to Mycobacterium avium subspecies paratuberculosis (MAP). Such exposure avenues are especially relevant for dairy farms practicing good management procedures since calves on these farms could be infected via dams that have yet to be identified as MAP-positive. Indeed, of 18 calves in the present study that became paratuberculosis parameter-positive, five had dams that were negative for all parameters pre-calving. Parameters used herein to define paratuberculosis status were serum ELISA, serum agar gel immunodiffusion, cultureable fecal MAP, histopathology at necropsy and clinical disease. Thirty-four newborn calves whose dams were paratuberculosis-positive were assigned to four different treatment groups. Ten were treated daily for 60 days with viable Dietzia added to their antibiotic-free milk feedings; none became positive for any parameter with age. In contrast, seven of eight calves that were not treated became positive for one or more paratuberculosis-associated parameter. Sixteen calves were treated with viable Dietzia for the first two days of life; eight were then not treated further, whereas the other eight were treated an additional 58 days with Dietzia added to tetracycline-fortified milk (Dietzia is sensitive to tetracycline). In these two groups, positivity developed in five of eight and six of eight, respectively. These results indicated that (a) a daily, 60-day treatment with viable Dietzia effectively prevented development of parameters indicative of paratuberculosis and (b) this treatment, in combination with good management practices, has the potential to eradicate MAP from animals/herds, which should curtail the spread of MAP. Such results should significantly reduce human exposure to MAP, which in turn, could have relevance for the controversial role of MAP in Crohn's disease, type-1 diabetes mellitus, sarcoidosis, Blau syndrome, ulcerative colitis, irritable bowel syndrome and multiple sclerosis