In this study, variably absent or present (VAP) regions discovered through comparative genomics experiments were targeted for the development of a rapid, PCR-based method to subtype and fingerprint Escherichia coli O157:H7. Forty-four VAP loci were analyzed for discriminatory power among 79 E. coli O157:H7 strains of 13 phage types (PT). Twenty-three loci were found to maximize resolution among strains, generating 54 separate fingerprints, each of which contained strains of unique PT. Strains from the three previously identified major E. coli O157:H7 lineages, LSPA6-LI, LSPA6-LI/II, and LSPA6-LII, formed distinct branches on a dendrogram obtained by hierarchical clustering of comparative genomic fingerprinting (CGF) data. By contrast, pulsed-field gel electrophoresis (PFGE) typing generated 52 XbaI digestion profiles that were not unique to PT and did not cluster according to O157:H7 lineage. Our analysis identified a subpopulation comprised of 25 strains from a closed herd of cattle, all of which were of PT87 and formed a cluster distinct from all other E. coli O157:H7 strains examined. CGF found five related but unique fingerprints among the highly clonal herd strains, with two dominant subtypes characterized by a shift from the presence of locus fprn33 to its absence. CGF had equal resolution to PFGE typing but with greater specificity, generating fingerprints that were unique among phenotypically related E. coli O157:H7 lineages and PT. As a comparative genomics typing method that is amenable for use in high-throughput platforms, CGF may be a valuable tool in outbreak investigations and strain characterization.
- American Society for Microbiology
- Rapid determination of escherichia coli o157:h7 lineage types ...
Rapid determination of escherichia coli o157:h7 lineage types and molecular subtypes by using comparative genomic fingerprinting
Courtesy of American Society for Microbiology
Large scale dairy farmers in need of a solution - Case Study
Alsafi Danone is one of the largest integrated dairy farms in the world. Controlling fallen stock and bio-security is critical to the upkeep of a healthy productive herd.Riyadh, Saudi ArabiaClient overviewAlsafi Danone, are the largest integrated dairy farm in the world. They first opened in 1979 and have has since expanded to a herd of over 37,000 cows who produce 700, 000 litres of milk every day. They are widely recognised as one of the leading, high-quality dairy producer and has been rewarded with an ISO...
Managing Livestock Medicine
In an ideal world, our cattle would never get sick. But this is the real world, and you need to be prepared. Not only should you have the right medical supplies for your livestock on hand, but also be aware of how to store and handle your livestock medicine. Storage Facilities Ideally, maintaining a facility that stores your medicine will keep you organized. Of course, you don’t want to be administering the wrong medicine to your herd. However, it should also protect your medicine from external factors...
Bull Calves Need Care Too
By far, most bull calves will never become a lasting benefit to a dairy herd, and as such may not always receive the same level of care that heifer calves do. Harmonizing your calf rearing programs will yield positive results for all calves and your bottom line. All calves require excellent care, especially in the first few days of life. Without adequate, timely colostrum and proper milk replacer/milk intake, heifer calves will produce less milk later in life, not to mention reduced likelihood of entering the...
Surprising ways Kenyans are embracing climate-smart agriculture
In rural Kenya, where it may only rain twice per year, farmers and herders are embracing so-called “climate-smart” agriculture. The video above, produced by the World Bank, begins by showing how John and Mary Obuom have transformed their one-acre farm into a model of sustainable practices. The family plants a diversity of crops in case one or more fails in a given year. A thicket of cashew trees increases income while providing shade and removing carbon from the air. And an elevated pen for livestock...
From the American prairie, a conservation success story
From rhinos to #CecilTheLion, we live in a world where stories of species loss and illegal wildlife trade dominate the conservation headlines, so a good news story every now and then is a welcome surprise. Three years ago, 63 bison originally from Yellowstone National Park left a quarantine facility just outside the park’s boundary where they were being monitored for brucellosis and made the journey nearly 400 miles to the Fort Peck Reservation in northeastern Montana. The transfer, which brought bison...