Genotyping North American animal Mycobacterium bovis isolates using multilocus variable number tandem repeat analysis.

Multilocus variable number tandem repeat analysis (MLVA) has recently emerged as a genotyping method that is both robust and highly discriminatory for the differentiation of Mycobacterium tuberculosis complex (MTBC) strains, including Mycobacterium bovis. However, MLVA assessment of M. bovis isolates recovered from animals in North America has been limited. Using an epidemiologically diverse set of 41 North American M. bovis animal isolates, MLVA, based on 27 published variable number tandem repeat (VNTR) loci, was evaluated. Nineteen loci displayed polymorphism, which resulted in differentiation of 21 unique MLVA genotypes. A subset of 6 loci differentiated the isolates into 14 genetically related groups that displayed remarkable concordance with the epidemiological data gathered via traditional trace-back methods. In most cases, MLVA exhibited greater resolution than spoligotyping, which differentiated the isolates into 11 groups. MLVA genotyping of M. bovis shows great potential as a molecular typing tool for characterizing the epidemiology of M. bovis animal infections in North America. However, the greatest resolution was achieved by using a combination of both MLVA and spoligotyping.

Evaluation of a four year intervention to reduce musculoskeletal hazards among berry growers.

PROBLEM: Fresh market berry production workers are exposed to physical risk factors for musculoskeletal injury. METHOD: We disseminated information through trade publications and other sources to berry managers in seven U.S. states about five prevention through design practices that were both safer and more profitable than traditional methods. We administered mail evaluation questionnaires prior to the intervention and after each of four intervention years to rolling, independent U.S. samples and to comparison New Zealand berry farm manager samples after years one through three. RESULTS: U.S. manager self-reports of reading trade publication information increased compared to baseline values for two of five practices and self-reported awareness increased for four of five practices. There were no increases in adoption. More U.S. than New Zealand managers reported getting information about two practices from trade publications and about four practices from public events. No U.S. versus New Zealand differences were observed in reported awareness or adoption for any practice. IMPACT ON INDUSTRY: This study showed that even a modest campaign can build awareness of safer practices fairly quickly in three to four years among small agricultural firms but that increasing adoption apparently requires more time. Widespread adoption of safer practices could help keep operators in business longer as they age by reducing the workload and musculoskeletal strain associated with labor intensive crop production for them and their workforce. Adoption of practices that also improve profits, like the five practices featured in this study, could also help managers stay in business.

Abattoir surveillance: the U.S. experience.

Abattoir, or slaughter, surveillance has been an important component of bovine tuberculosis control and eradication programs in the U.S., and has adapted to changes in the livestock market from farm to table, and the threat of bovine tuberculosis from a wildlife reservoir. The purpose of this overview was to describe the current goals of U.S. bovine tuberculosis slaughter surveillance, describe the elements of slaughter surveillance in the U.S., describe enhancements to the slaughter surveillance system, and discuss future challenges for the U.S. bovine tuberculosis surveillance program. Government regulations and the scientific literature were examined to provide information for this paper. The control and eradication of bovine tuberculosis in livestock falls to the United States Department of Agriculture and two agencies within the Department: the Food Safety and Inspection Service (FSIS) and the Animal and Plant Health Inspection Service (APHIS). FSIS conducts routine slaughter surveillance for disease or conditions that render carcasses unsuitable for human consumption, while APHIS is involved in antemortem bovine tuberculosis testing, and necropsy and investigation of bovine tuberculosis cases identified through slaughter surveillance or antemortem testing. Results from the previous 5 years of surveillance are presented. Enhancements have been added to the current surveillance system to improve its performance. An incentive program has been used to increase the numbers of tissues submitted for laboratory examination, the state of Michigan is implementing electronic animal identification under a pilot program, and expansions to the current system are being developed to accommodate new livestock industries. The success of these programs and challenges for the future are discussed.