Enterobacteriaceae-associated blaCTX-M genes have become globally widespread within the past 30 years. Among isolates from Washington State cattle, Escherichia coli strains carrying blaCTX-M (CTX-M ...E. coli strains) were absent from a set of 2008 isolates but present in a set of isolates from 2011. On 30 Washington State dairy farms sampled in 2012, CTX-M E. coli prevalence was significantly higher on eastern than on northwestern Washington farms, on farms with more than 3,000 adult cows, and on farms that recently received new animals. The addition of fresh bedding to calf hutches at least weekly and use of residual fly sprays were associated with lower prevalence of CTX-M E. coli. In Washington State, the occurrence of human pathogens carrying blaCTX-M genes preceded the emergence of blaCTX-M-associated E. coli in cattle, indicating that these resistance determinants and/or their bacterial hosts may have emerged in human populations prior to their dissemination to cattle populations.
To describe the number and types of veterinary professional degree and certificate programs providing education in the area of public practice to veterinarians and determine the availability of these ...programs via distance learning.
Web-based internet searches were performed for programs for veterinary public practice or public health, population medicine, or Master's degree in Epidemiology. The information reviewed was derived from individual school and program Web sites and from personal e-mail correspondence with school administrators.
17 professional degree and 4 certificate programs were available to provide education and training in the areas of public practice and population medicine to veterinarians. Twelve of these programs have begun since 1998. Of the 17 professional degree programs, 7 are located in the United States and 10 are located in other countries. Nine of the professional degree programs provide education through traditional teaching methods, and 8 provide education and training through distance learning.
During the preceding 5 years, the number of programs available to educate and train veterinarians in the areas of public practice and population medicine has increased. Distance learning is being used to increase capacity and reach a broader audience of veterinarians. With the increase in programs has come an increase in capacity to educate and train veterinarians in the fields of population medicine and public practice. The impact and sustainability of this increased capacity have not been evaluated.
To analyze data for 60 poultry flocks voluntarily enrolled in the Pennsylvania Salmonella enteritidis Pilot Project and determine management and environmental risk factors associated with production ...of S enteritidis-contaminated eggs.
60 flocks for which at least 1 environmental sample (manure or egg-handling equipment) was positive for S enteritidis.
Samples of manure, egg-handling equipment, and mice were submitted for bacterial culture of S enteritidis. When S enteritidis was isolated from environmental samples, 1,000 eggs were collected from the flock every 2 weeks for 8 weeks and submitted for bacterial culture.
18 flocks were found to have produced contaminated eggs. Estimated overall prevalence of contaminated eggs was 2.64/10,000 eggs produced, but flock-specific prevalence ranged from 0 to 62.5/10,000 eggs. Flocks with high levels of manure contamination were 10 times as likely to produce contaminated eggs as were flocks with low levels. However, 5 flocks with low levels of manure contamination produced contaminated eggs.
Evaluation of the level of manure contamination could be used to help identify flocks at risk of producing S enteritidis-contaminated eggs.
Flocks with high levels of S enteritidis-contaminated manure appeared to pose the greatest public health threat, and on-farm programs to reduce the prevalence of egg contamination should be developed for farms with high levels of manure contamination. Efforts to reduce the overall number of on-farm pathogens should decrease the incidence of foodborne disease in humans.
The purpose of this study was to investigate the genetic similarity of
Campylobacter jejuni and
Campylobacter coli with similar antimicrobial resistance phenotypes, isolated from cattle on different ...farms and at different times, in order to evaluate the possible existence of disseminated antimicrobial resistant clones. PFGE after
SmaI and
KpnI restriction identified 23 and 16 distinct PFGE patterns among 29
C. jejuni and 66
C. coli isolates, respectively. In
C. coli, 51 (77%) of the resistant isolates demonstrated one of the four indistinguishable PFGE patterns, whereas only 24% doxycycline resistant
C. jejuni shared one of the two indistinguishable PFGE patterns. The genetic mechanisms of resistance were homogeneous within and between these clonal types. Genetically indistinguishable (clonal) groups of
C. coli accounted for most
Campylobacter sp. with multiple antimicrobial resistance observed in this study, consistent with a role for clonal dissemination in the epidemiology of resistance in this species.
Gastrointestinal disease (GI) is the most common illness in pre-weaned dairy calves. Studies have associated the fecal microbiome composition with health status, but it remains unclear how the ...microbiome changes across different levels of GI disease and breeds. Our objective was to associate the clinical symptoms of GI disease with the fecal microbiome. Fecal samples were collected from calves (n = 167) of different breeds (Holstein, Jersey, Jersey-cross and beef-cross) from 4-21 d of age. Daily clinical evaluations assessed health status. Calves with loose or watery feces were diagnosed with diarrhea and classified as bright-sick (BS) or depressed-sick (DS) according to behavior. Calves with normal or semiformed feces and no clinical illness were classified as healthy (H). One hundred and three fecal samples were obtained from consistently healthy calves and 64 samples were from calves with diarrhea (n = 39 BS; n = 25 DS). The V3-V4 region of 16S rRNA gene was sequenced and analyzed. Differences were identified by a linear-mixed effects model with a negative binomial error. DS and Jersey calves had a higher relative abundance of Streptococcus gallolyticus relative to H Holstein calves. In addition, DS calves had a lower relative abundance of Bifidobacterium longum and an enrichment of Escherichia coli. Species of the genus Lactobacillus, such as an unclassified Lactobacillus, Lactobacillus reuteri, and Lactobacillus salivarius were enriched in calves with GI disease. Moreover, we created a model to predict GI disease based on the fecal microbiome composition. The presence of Eggerthella lenta, Bifidobacterium longum, and Collinsella aerofaciens were associated with a healthy clinical outcome. Although lactobacilli are often associated with beneficial probiotic properties, the presence of E. coli and Lactobacillus species had the highest coefficients positively associated with GI disease prediction. Our results indicate that there are differences in the fecal microbiome of calves associated with GI disease severity and breed specificities.
Objective—To assess the use of flunixin meglumine as an adjunct treatment for diarrhea in calves. Design—Clinical trial. Animals—115 calves with diarrhea that were 1 to 21 days old at enrollment. ...Procedure—Calves that developed diarrhea were randomly assigned to receive no flunixin meglumine (controls), a single dose of flunixin meglumine (2.2 mg/kg 1.0 mg/lb), or 2 doses of flunixin meglumine administered 24 hours apart. Serum IgG concentration and PCV were measured prior to enrollment in the trial. Calves were evaluated daily to determine rectal temperature, fecal consistency, demeanor, and skin elasticity score . The primary analytic outcome was days of sickness (morbiddays). Results—Calves with fecal blood and treated with a single dose of flunixin meglumine had fewer morbiddays and antimicrobial treatments, compared with controls. Although not significant, calves given 2 doses of flunixin meglumine in 24 hours had fewer morbid-days than untreated control calves. Regardless of severity of diarrhea, calves without fecal blood did not benefit from the use of flunixin. For calves with fecal blood, failure of passive transfer (low serum IgG concentration) was an independent risk factor for increased morbid-days. Conclusions and Clinical Relevance—Treatment with a single dose of flunixin meglumine resulted in fewer antimicrobial treatments and morbid-days in calves with fecal blood. As observed in other studies, calves with failure of passive transfer were at high risk for poor outcomes. This emphasizes the importance of developing and implementing effective colostrum delivery programs on dairy farms.
The issue of antimicrobial resistance in food animal agriculture was addressed by conducting clinical trials to assess alternatives to antimicrobials in dairy calf-raising and developing outreach to ...three different audiences. Current research was integrated into Extension programs for calf-raisers, animal science and veterinary students, and food animal veterinarians. A complex issue such as resistance in bacteria from the use of antimicrobials in food animal agriculture requires an integrated approach--from the science to its translation to judicious drug use on-farm but also a wide reach, to multiple audiences. (Contains 1 table.)
The implementation of testing processes to identify disease risk in new dairy cattle for reducing disease, boosting herd health and cutting costs, is discussed. Good management practices for ...bio-security focus on efforts to prevent the entry of diseases onto the farm as well as to prevent disease transmission within the farm. It is observed that that there are opportunities for dairy advisors, herd veterinarians and extension educators to emphasize the risks associated with new herd members and to work with clients on appropriate purchasing and testing strategies. The results show that keeping infectious diseases and other cattle conditions out of the herd can efficiently save money.
Multidrug-resistant (MDR)
can be spread from cattle to humans through direct contact with animals shedding
as well as through the food chain, making MDR
a serious threat to human health. The ...objective of this study was to use whole-genome sequencing to compare antimicrobial-resistant (AMR)
serovars Typhimurium, Newport, and Dublin isolated from dairy cattle and humans in Washington State and New York State at the genotypic and phenotypic levels. A total of 90 isolates were selected for the study (37
Typhimurium, 32
Newport, and 21
Dublin isolates). All isolates were tested for phenotypic antibiotic resistance to 12 drugs using Kirby-Bauer disk diffusion. AMR genes were detected in the assembled genome of each isolate using nucleotide BLAST and ARG-ANNOT. Genotypic prediction of phenotypic resistance resulted in a mean sensitivity of 97.2 and specificity of 85.2. Sulfamethoxazole-trimethoprim resistance was observed only in human isolates (
< 0.05), while resistance to quinolones and fluoroquinolones was observed only in 6
Typhimurium isolates from humans in Washington State.
Newport isolates showed a high degree of AMR profile similarity, regardless of source.
Dublin isolates from New York State differed from those from Washington State based on the presence/absence of plasmid replicons, as well as phenotypic AMR susceptibility/nonsusceptibility (
< 0.05). The results of this study suggest that distinct factors may contribute to the emergence and dispersal of AMR
in humans and farm animals in different regions.
The use of antibiotics in food-producing animals has been hypothesized to select for AMR
and associated AMR determinants, which can be transferred to humans through different routes. Previous studies have sought to assess the degree to which AMR livestock- and human-associated
strains overlap, as well as the spatial distribution of
's associated AMR determinants, but have often been limited by the degree of resolution at which isolates can be compared. Here, a comparative genomics study of livestock- and human-associated
strains from different regions of the United States shows that while many AMR genes and phenotypes were confined to human isolates, overlaps between the resistomes of bovine and human-associated
isolates were observed on numerous occasions, particularly for
Newport. We have also shown that whole-genome sequencing can be used to reliably predict phenotypic resistance across
isolated from bovine sources.
Food production processes are increasingly influenced by quality and safety concerns. For dairy production, one of the food quality outcomes is a low level of bacteria in unprocessed milk. A putative ...on-farm control point for low levels of bacteria is teat and udder cleaning before milking. Currently there are no appropriate on-farm schemes to monitor the effectiveness of different processes used to prepare cows for milking. The purpose of this project was to compare levels of teat skin bioluminescence with direct bacterial culture as a tool to evaluate teat cleanliness of dairy cows. Bioluminescence demonstrated average changes in cow cleanliness as animals proceeded through the premilking sanitation steps and, in that manner, could be used as a tool to demonstrate the effectiveness of the process.
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