•Over 7% of sampled beef cattle (<30 months of age) were shedding leptospires in urine.•Beef cattle were positive for exposure to serogroup Australis, as well as serogroup Sejroe.•High throughput ...culture analysis of cattle for leptospires is readily achieved using urine.•Seroprevalence does not correlate with shedding of leptospires.
Pathogenic leptospires colonize the renal tubules of reservoir hosts of infection, including cattle, and are excreted via urine. In order to identify circulating serovars of pathogenic leptospires in beef cattle, and their associated rates of urinary excretion, a cross sectional study was performed. Fifty urine samples were collected one day each month over 12 consecutive months (N = 600), directly from the bladder of beef cattle at a single slaughter facility and assessed for the presence of leptospires by culture and the fluorescent antibody test (FAT). Where possible, a matched serum sample was also collected for the microscopic agglutination test (MAT). Forty-three urine samples were either culture positive or FAT positive, indicating that 7.2% of sampled beef cattle were actively excreting leptospires in urine. Twenty-three urine samples were culture positive. Sequence analysis of 16S ribosomal DNA and secY indicated that all isolates were Leptospira borgpetersenii. Typing by serology indicated that all isolates were serogroup Sejroe. An overall seroprevalence of 20% (MAT ≥ 1:25) was determined; positive bovine sera was most reactive to serogroup Sejroe (serovar Hardjo) (8.1%), and serogroup Australis (serovar Bratislava) (6.7%). There was poor correlation between seroprevalence and excretion of leptospires since 18/43 (41.9%) cattle, which were positive by culture or FAT, were seronegative. The virulence of two selected isolates of L. borgpetersenii was confirmed by experimental infection in small animal models of infection. Results confirm that L. borgpetesenii continues to circulate in beef cattle and that multiple diagnostic assays are required to detect active shedding. These findings also highlight beef cattle as a reservoir host for the potential zoonotic transmission of leptospires.
The zoonotic risk posed to employees by slaughtering feral swine (Sus scrofa) at two abattoirs in Texas was assessed by testing feral swine serum samples for exposure to influenza A virus, ...Leptospira, Trichinella spiralis, and Toxoplasma gondii. Blood was collected from a total of 376 feral swine between the two facilities during six separate collection periods in 2015. Antibodies to one or more serovars of Leptospira were identified in 48.9% of feral swine tested, with Bratislava and Pomona as the most commonly detected serovars, and antibodies to influenza A virus were detected in 14.1% of feral swine. Antibodies to T. gondii and T. spiralis were identified in 9.0 and 3.5%, respectively, of feral swine tested. Our results suggest that abattoir employees should be aware of the potential for exposure to various zoonotic pathogens when slaughtering feral swine, wear appropriate personal protective equipment, and participate in medical monitoring programs to ensure detection and prompt treatment. In addition, consumers of feral swine should cook the meat to the appropriate temperature and wash hands and kitchen surfaces thoroughly after preparing meat.
This work examines Kant's remarkable decision to rewrite the core argument of the first Critique, the Transcendental Deduction of the Categories. I identify a two-part structure common to both ...versions: first establishing an essential role for the categories in unifying sensible intuitions; and then addressing a worry about how the connection between our faculties asserted in the first part is possible. I employ this structure to show how Kant rewrote the argument, focusing on Kant's response to the concerns raised in an early review by Johann Schultz. Schultz's dissatisfaction with the original Deduction lies in its second part, and Kant's subsequent revisions are focused on providing a better answer to this how-possible question. The new Deduction offers a more direct and convincing account of how our faculties work together to make experience possible.
The prevalence and concentration of many foodborne pathogens exhibit seasonal patterns at different stages of the farm-to-table continuum. Escherichia coli O157:H7 is one such pathogen. While ...numerous studies have described the seasonal trend of E. coli O157:H7 in live cattle, ground beef, and human cases, it is difficult to relate the results from these different studies and determine the interrelationships that drive the seasonal pattern of beef-related human illnesses. This study uses a common modeling approach, which facilitates the comparisons across data sets, to relate prevalence in live cattle to raw ground beef and human illness. The results support an intuitive model where a seasonal rise of E. coli O157:H7 in cattle drives increased ground beef prevalence and a corresponding rise in the human case rate. We also demonstrate the use of these models to assess the public health impact of consumer behaviors. We present an example that suggests that the probability of illness, associated with summertime cooking and handling practices, is not substantially higher than the baseline probability associated with more conventional cooking and handling practices during the remainder of the year.
US Department of Agriculture Food Safety and Inspection Service (FSIS) data on Salmonella enterica serotype Enteritidis in broiler chicken carcass rinses collected from 2000 through 2005 showed the ...annual number of isolates increased >4-fold and the proportion of establishments with Salmonella Enteritidis-positive rinses increased nearly 3-fold (test for trend, p<0.0001). The number of states with Salmonella Enteritidis in broiler rinses increased from 14 to 24. The predominant phage types (PT) were PT 13 and PT 8, 2 strains that a recent Foodborne Diseases Active Surveillance Network (FoodNet) case-control study associated with eating chicken. FSIS is directing more sampling resources toward plants with marginal Salmonella control to reduce prevalence in products including broilers. The policy targets establishments with common Salmonella serotypes of human illness, including Salmonella Enteritidis. Voluntary interventions should be implemented by industry.
As laying hens age, egg production and quality decreases. Egg producers can impose an induced molt on older hens that results in increased egg productivity and decreased hen mortality compared with ...non-molted hens of the same age. This review discusses the effect of induced molting by feed removal on immune parameters,
Salmonella enterica serovar Enteritidis (SE) invasion and subsequent production of SE-contaminated eggs. Experimental oral infections with SE show molted hens are more susceptible to SE infection and produce more SE-contaminated eggs in the first few weeks post-molt compared with pre-molt egg production. In addition, it appears that molted hens are more likely to disseminate SE into their environment. Molted hens are more susceptible to SE infection by contact exposure to experimentally infected hens; thus, transmission of SE among molted hens could be more rapid than non-molted birds. Histological examination of the gastrointestinal tracts of molted SE-infected hens revealed more frequent and severe intestinal mucosal lesions compared with non-molted SE-infected hens. These data suggest that induced molting by feed deprivation alters the normal asymptomatic host–pathogen relationship. Published data suggest the highest proportion of SE-positive eggs is produced within 1–5 weeks post-molt and decreases sharply by 6–10 weeks and dissipates to the background level for non-molted hens by 11–20 weeks. Appropriate treatment measures of eggs produced in the fist 5 weeks post-molting may decrease the risk of foodborne infections to humans.
There is no suitable model for predicting thermal inactivation kinetics of Salmonella spp. for many types of liquid egg products, including salted liquid egg yolk, for use in updating U.S. Department ...of Agriculture (USDA) pasteurization guidelines. This is because, in part, of the variations in Salmonella strains and the changes in the processing of liquid egg products over the past 40 years. The objectives of the present study were to determine the thermal inactivation kinetics and to create a general thermal inactivation kinetics model that can be used for estimating log reductions of salmonellae in 10% salted liquid egg yolk for temperatures between 62.2 and 69°C. This model can be used by processors to help ensure adequate pasteurization. This was accomplished by studying the inactivation kinetics of a three-strain composite of heat-resistant Salmonella serovars Enteritidis and Oranienburg, inoculated into commercially processed 10% salted liquid egg yolk. The survival curves were convex, with asymptotic D-values. From these curves, a general model was developed to predict log reductions for given times at specified temperatures. For example, at a temperature of 67.3°C (153.1°F) for 3.5 min, our model predicts a 5-log reduction would be obtained, whereas with the current USDA minimum required pasteurization regimen (63.33°C 146°F for 3.5 min), our model predicts that a reduction of only 2.7 log would be obtained. The results of this study provide information that can be used by processors to aid in producing safe, pasteurized egg yolk products, and for satisfying USDA pasteurization performance standards and developing industry guidance.
Both parties in the active philosophical debate concerning the conceptual character of perception trace their roots back to Kant's account of sensible intuition in the Critique of Pure Reason. This ...striking fact can be attributed to Kant's tendency both to assert and to deny the involvement of our conceptual capacities in sensible intuition. He appears to waver between these two positions in different passages, and can thus seem thoroughly confused on this issue. But this is not, in fact, the case, for, as I will argue, the appearance of contradiction in his account stems from the failure of some commentators to pay sufficient attention to Kant's developmental approach to philosophy. Although he begins by asserting the independence of intuition, Kant proceeds from this nonconceptualist starting point to reveal a deeper connection between intuitions and concepts. On this reading, Kant's seemingly conflicting claims are actually the result of a careful and deliberate strategy for gradually convincing his readers of the conceptual nature of perception.
Attempts to justify the special moral status of human beings over other animals face a well‐known objection: the challenge of marginal cases. If we attempt to ground this special status in the unique ...rationality of humans, then it becomes difficult to see why nonrational humans (infants, the severely cognitively disabled, and so on) should be treated any differently than other, nonhuman animals. We respond to this challenge by turning to the social contract tradition. In particular, we identify an important role for the concept of recognition in attempts to secure rights through a social contract. Recognition, which involves identifying with or seeing ourselves as others, is the key to establishing the scope of justice, and we argue that this scope extends to all humans—even the so‐called marginal cases—but not to other animals. If this is correct, then we have a principled reason for why all humans have certain rights that other animals lack.
The paper describes a method for planning energy-efficient trajectories for the booms of hydraulic mobile cranes in (semi)autonomous operation. The method includes a learning step, in which a ...multi-physics model of the crane is used to calculate weight matrices for the path planning algorithm. This step requires considerable time but adjusts the method to the mechanical structure and hydraulic system of the particular crane. At the implementation step, when the calculated matrices are used to build energy-efficient trajectories, the method is fast enough to be run in real time. The paper considers a control algorithm that allows moving the crane booms automatically according to the built trajectory. The simulation experiments demonstrate energy savings with the median value of approximately 5% for energy-efficient trajectories in comparison with the shortest paths.
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