A one health perspective on dairy production and dairy food safety.

As the global population approaches 9.7 billion inhabitants by the year 2050, humanity faces enormous challenges to feed, house, and provide basic living requirements for the growing population while preserving the health of wildlife and the ecosystem. Dairy source foods play an important part in providing nutrient and energy dense sources of calories and establishing Bifidobacterium as a keystone species in the gut for positive health outcomes in infants and children. In developed countries, dairy products have a high food safety record when pasteurized and properly processed. However, when milk is consumed unpasteurized, as often occurs in developing countries where regulation and oversight of the dairy industry is lacking, dairy can serve as a vector for zoonotic transmission of disease and can contain adulterants such as antibiotic residues. Here we provide an overview for the importance of dairy source foods for nutrition and with a One Health perspective and discuss the historical events that have resulted in a high standard of dairy food safety in the United States. This review article covers the Origins of One Health, the role of milk in transmission of disease, management practices and regulations to ensure safe dairy products reach consumers, current challenges facing the dairy industry and impacts on public health, and how these standards can be employed in low and middle income countries to improve public health, nutrition and economic benefits to farmers.

Impact of vacuum cooling on Escherichia coli O157:H7 infiltration into lettuce tissue.

Vacuum cooling is a common practice in the California leafy green industry. This study addressed the impact of vacuum cooling on the infiltration of Escherichia coli O157:H7 into lettuce as part of the risk assessment responding to the E. coli O157:H7 outbreaks associated with leafy green produce from California. Vacuum cooling significantly increased the infiltration of E. coli O157:H7 into the lettuce tissue (2.65E+06 CFU/g) compared to the nonvacuumed condition (1.98E+05 CFU/g). A stringent surface sterilization and quadruple washing could not eliminate the internalized bacteria from lettuce. It appeared that vacuuming forcibly changed the structure of lettuce tissue such as the stomata, suggesting a possible mechanism of E. coli O157:H7 internalization. Vacuuming also caused a lower reduction rate of E. coli O157:H7 in stored lettuce leaves than that for the nonvacuumed condition.

Teratogenic bluetongue and related orbivirus infections in pregnant ruminant livestock: timing and pathogen genetics are critical.

Congenital infections of domestic animals with viruses in several families, including Bunyaviridae, Flaviridae, Parvoviridae, and Reoviridae, are the cause of naturally occurring teratogenic central nervous system and/or musculoskeletal defects (arthrogryposis) in domestic animals. Congenital infections of ruminant livestock with bluetongue virus (BTV) and some related members of the genus Orbivirus (family Reoviridae) have clearly shown the critical role of gestational age at infection in determining outcome. Specifically, fetuses infected prior to mid-gestation that survive congenital BTV infection are born with cavitating central nervous system defects that range from severe hydranencephaly to cerebral cysts (porencephaly). Generally, the younger the fetus (in terms of gestational age) at infection, the more severe the teratogenic lesion at birth. Age-dependent virus infection and destruction of neuronal and/or glial cell precursors that populate the developing central nervous system are responsible for these naturally occurring virus-induced congenital defects of animals, thus lesions are most severe when progenitor cells are infected prior to their normal migration during embryogenesis. Whereas congenital infection is characteristic of certain BTV strains, notably live-attenuated (modified-live) vaccine viruses that have been passaged in embryonating eggs, transplacental transmission is not characteristic of many field strains of the virus and much remains to be determined regarding the genetic determinants of transplacental transmission of individual virus strains.

One Health in food safety and security education: Subject matter outline for a curricular framework.

Educating students in the range of subjects encompassing food safety and security as approached from a One Health perspective requires consideration of a variety of different disciplines and the interrelationships among disciplines. The Western Institute for Food Safety and Security developed a subject matter outline to accompany a previously published One Health in food safety and security curricular framework. The subject matter covered in this outline encompasses a variety of topics and disciplines related to food safety and security including effects of food production on the environment. This subject matter outline should help guide curriculum development and education in One Health in food safety and security and provides useful information for educators, researchers, students, and public policy-makers facing the inherent challenges of maintaining and/or developing safe and secure food supplies without destroying Earth's natural resources.

Antimicrobial properties of the chelating agent EDTA on Streptococcal bovine mastitis isolates.

To determine the efficacy of the chelating agent EDTA on microbial growth, separate cultures of two streptococcal bovine mastitis isolates, Streptococcus agalactiae and Streptococcus uberis, were exposed to known concentrations of EDTA. Bacterial cultures of 10(8) CFU/ml were exposed to concentrations of EDTA ranging from 30 to 100 mM in an in-vitro-milk environment. Multiple replications of cultures exposed to EDTA were plated during a two-hour time course. A concentration of 100 mM EDTA resulted in a 90% reduction of S. agalactiae and a 99% reduction of S. uberis. Under these experimental conditions, EDTA treatments in cultures of both isolates exhibited from 1 to 2 log reductions suggesting that EDTA is a potentially effective antimicrobial against streptococcal isolates implicated in causing bovine mastitis.

Zoological medicine and public health.

Public-health issues regarding zoological collections and free-ranging wildlife have historically been linked to the risk of transmission of zoonotic diseases and accidents relating to bites or injection of venom or toxins by venomous animals. It is only recently that major consideration has been given worldwide to the role of the veterinary profession in contributing to investigating zoonotic diseases in free-ranging wildlife and integrating the concept of public health into the management activities of game preserves and wildlife parks. At the veterinary undergraduate level, courses in basic epidemiology, which should include outbreak investigation and disease surveillance, but also in population medicine, in infectious and parasitic diseases (especially new and emerging or re-emerging zoonoses), and in ecology should be part of the core curriculum. Foreign diseases, especially dealing with zoonotic diseases that are major threats because of possible agro-terrorism or spread of zoonoses, need to be taught in veterinary college curricula. Furthermore, knowledge of the principles of ecology and ecosystems should be acquired either during pre-veterinary studies or, at least, at the beginning of the veterinary curriculum. At the post-graduate level, master's degrees in preventive veterinary medicine, ecology and environmental health, or public health with an emphasis on infectious diseases should be offered to veterinarians seeking job opportunities in public health and wildlife management.

A multiplex PCR for simultaneous detection and differentiation of North American serotypes of bluetongue and epizootic hemorrhagic disease viruses.

In the present study, a multiplex RT-PCR-based assay for simultaneous detection and differentiation of North American serotypes of bluetongue (BT) virus (BTV) and epizootic hemorrhagic disease (EHD) virus (EHDV) in cell culture and clinical samples was developed. Two pairs of primers (B1 and B4) and (E1 and E4) were designed to hybridize to non-structural protein 1 (NS1) genomes of (BTV-11) and (EHDV-1), respectively. The multiplex PCR-based assay utilized a single tube-PCR amplification in which EHDV and BTV primers were used simultaneously in a multiplex format. The BTV primers generated a 790 base pair (bp) specific PCR product from RNA samples of North American BTV serotypes 2, 10, 11, 13 and 17; whereas EHDV serotypes 1 and 2 or total nucleic acid extract from non-infected baby hamster kidney (BHK) cells failed to demonstrate the 790bp specific BTV PCR product. Likewise, the EHDV primers produced a 387bp specific PCR product from RNA samples of EHDV serotypes 1 and 2, but not from BTV serotypes 2, 10, 11, 13, 17 or from total nucleic acid extract of BHK cell controls. Two pairs of nested primers (B2 and B3) and (E2 and E3), internal to the annealing sites of primers (B1and B4) and primers (E1 and E4), produced a 520bp specific BTV and a 224bp specific EHDV PCR product from BTV and EHDV first amplification products, respectively. These nested amplifications increased the sensitivity of the PCR assay and confirmed the specificity of the first amplified EHDV or BTV PCR products. The described multiplex RT-PCR-based assay could be used to facilitate rapid detection and differentiation of North American BTV and EHDV serotypes and to provide a valuable tool to study the epidemiology of these orbivirus infections in susceptible animal populations.

Defining the attributes expected of graduating veterinary medical students, part 2: external evaluation and outcomes assessment.

We have previously defined a set of 62 attributes-12 in the area of professional characteristics, 28 addressing knowledge and understanding, and 22 delineating skills-that veterinary students should be expected to have demonstrated by the time of their graduation (Walsh DA, Osburn BI, Christopher MM. Defining the attributes expected of graduating veterinary medical students. J Am Vet Med Assoc 219:1358-1365, 2001). We have used this set of attributes as the basis of an outcomes assessment completed by California practitioners to determine whether graduates from the University of California School of Veterinary Medicine are meeting these expectations. Based upon this assessment, these 62 defined attributes appear to reflect very well practicing veterinarians' views and expectations of DVM graduates. The survey results also indicate that, overall, the recent University of California graduates are meeting these set of expectations. Simultaneously, the outcomes assessment focused attention on several areas, including private practice management, work expectations for successful practice, and surgical capabilities. For each, California practitioners recommended that the definition of the expectation be expanded and that the level of achievement by graduates be improved. Defining a set of attributes expected of veterinary graduates is a key step in obtaining an effective outcomes assessment of a professional educational program.

Baseline survey of progress by veterinary medical colleges in implementing recommendations from the North American Veterinary Medical Education Consortium.

A survey was conducted to assess progress by accredited veterinary medical colleges in the United States and Canada with regard to implementation of recommendations from the North American Veterinary Medical Education Consortium (NAVMEC). Results indicated broad support for many of the recommendations and a willingness among stakeholders in veterinary medical education to accelerate their implementation. Respondents also expressed a desire for evidence-based decisions and detailed implementation planning. Many colleges of veterinary medicine reported progress on initiatives started prior to the meetings of the NAVMEC that closely aligned with NAVMEC recommendations. Only isolated progress toward implementation of system-wide recommendations that required coordination among multiple colleges of veterinary medicine and other stakeholders was identified. Survey results confirmed the need for changes to the current veterinary medical education paradigm and a commitment among many stakeholders to work together to effect these changes.

Adventitious agents and smallpox vaccine in strategic national stockpile.

In keeping with current standards, we urge that old smallpox vaccines that were made in animal skin and are still a key part of our strategic national stockpile be tested for adventitious infectious agents. The advisory especially applies to viruses that have the potential for zoonotic transmission to human vaccine recipients.