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This article discusses the antimicrobial resistance for Salmonella enterica serovar Typhimurium (ST) isolated from human and cattle sources in the Pacific Northwest of United States. Data point out to differences in the resistance patterns due to clonal dissemination of multidrug-resistant ST phage., We compared ant/microbial resistance patterns of Salmonella enter/ca serovar Typhimurium (ST) of isolates from humans (n = 715) and cattle (n = 378) in the Pacific Northwest from 1982 through [...]

Household contamination with Salmonella enterica increases when occupational exposure exists (cattle farms with known salmonellosis in cattle, a salmonella research laboratory, or a veterinary clinic experiencing an outbreak of salmonellosis). [...]

The expression patterns of clinical genotype I strains are compared with those of bovine-biased genotype 5 strains by using mciroarrays in order to determine whether inherent differences in gene expression have explained the variation in infectivity of these genotypes. The results have shown that the increased prevalence of Escherichia coli O157:H7 illness caused by clinical genotype I strains are because of the overexpression of key virulence genes, but the bovine-biased genotype 5 strains are more resistant to adverse environmental conditions.

The potential effects of ceftiofur on [bla.sub.CMY-2] transfer and dissemination are assessed by using an in vivo experimental study in which calves are inoculated with competent [bla.sub.CMY-2]-bearing plasmid donors and susceptible recipients. The studies have failed to support the major role for ceftiofur use in the maintenance and dissemination of [bla.sub.CMY-2]-bearing plasmid mediated cephalosporin resistance in commensal Escherichia coli and in pathogenic Salmonella in the diary cattle populations.

The enterohemorrhagic Escherichia coli serotypes O157:H7 and O157:H (EHEC-O157) isolates obtained from cattle are gentotyped to determine if the proportion of EHEC-O157 genotypes in the bovine reservoirs influenced the rates of the diverse international incidence of EHEC-O157 disease. The proportion of clinical genotypes among cattle isolates are weakly related to the international incidence of EHEC-O157-associated hemolytic-uremic syndrome, differed among clinical isolates internationally and along the putative cattle-hamburger-clinical case transmission chain.

The identification and investigation of the nucleotide sequence of the DNA of the SSuT (resistant to streptomycin, sulfadiazine, tetracycline) antimicrobial resistance genes and its distribution among strains of Escherichia coli and among cattle farms in Washington State are described. The results have shown that a large genetic element conferring the SSuT phenotype is responsible for maintenance of these traits owing to linkage to genetic traits that confer a selective advantage in the intestinal lumens of dairy calves.

The quantification and identification of Salmonella enterica burdens in harvest-ready cattle and specific at-risk populations of cattle most likely to harbor multiply resistant Salmonella enterica are described. The results have shown that although Salmonella enterica isolates are recoverable from harvest-ready cattle, multiply resistant variants are rare and are associated with specific serovars in cattle harvested because of poor productivity characteristics.

A study was conducted to characterize the bacteriophage insertion site genotype of Escherichia coli O157:H7 isolates from cattle and from humans and found increased genotype diversity among bovine isolates and differential representation of genotypes in these host species.

The tissue and digesta from along the gastrointestinal tract (GIT) were cultured for the bacteria to examine histologically the existance of lymphoid character. The study result shows that among animals with documented histories or long-duration Escherichia coli 0157:H7 colonization, the bacteria were cultured only from the rectoanal junction mucosa and not from the gall bladder or other GIT locations.

A study was conducted on the effect of antimicrobial drug resistance genes on Escherichia coli. It was observed that the greater fitness advantage of anti-microbial-resistant Escherichia coli in calves is in no way affected by the antimicrobial resistance genes, but the farm environment and the diet are clearly responsible for the maintenance of the microbial resistance genes.

The prevalence of Campylobacter jejuni in commercial feedlot cattle is monitored throughout the feeding period by repeated bacteriologic culture of feces. Results reveal apparent transmission of Campylobacter jejuni among feedlot cattle during the feeding period, unaffected by water chlorination, resulting in a high prevalence of Campylobacter jejuni excretion by cattle approaching slaughter.

The study regarding prevalence, distribution, and antimicrobial resistance of thermophilic Campylobacter jejuni, Campylobacter coli, and other thermophilic Campylobacter (OTC) species in cattle was conducted. It is demonstrated that Campylobacter jejuni is widely distributed among Washington cattle farms, while Campylobacter coli is more narrowly distributed but significantly more resistant.

Farmland biodiversity benefits pollination, biological control and other key ecosystem services. Food safety has been seen as an exception to this broader pattern, as diverse farmlands attract wildlife that vector foodborne human pathogens. Resulting mitigation efforts thus often seek to deter wildlife by removing natural habitats, while also excluding vertebrate livestock. However, surprising recent evidence suggests that farm simplification actually increases the likelihood that produce will be contaminated with human pathogens.Here, we consider the possibility that intensified agriculture harms faeces‐feeding (coprophagous) beetles and bacteria, which could contribute to heightened food‐safety risk. In 70 commercial vegetable fields spanning the US west coast, using either organic or conventional farming methods, we surveyed coprophages both above‐ and below‐ground. We also measured removal rates of the faeces of Sus scrofa, which vectors foodborne pathogens both as livestock and as feral wildlife.Above‐ground, organic farms fostered dung beetle species that removed S. scrofa faeces more rapidly than was seen on conventional farms, although this benefit was weakened in simplified landscapes dominated by pasture and an introduced dung beetle. Below‐ground, organic farming encouraged significantly higher biodiversity among soil bacteria. Organic farming similarly benefitted dung beetles and bacteria on farms that produced livestock alongside vegetables, or vegetables alone.Complementary laboratory experiments revealed that the dung beetle species and biodiverse bacterial assemblages typical of organic farms were significantly more effective at suppressing human‐pathogenic Escherichia coli O157:H7, compared to coprophage communities associated with conventional farms. This suggests that farm management practices, coprophage conservation, and human–pathogen suppression might be linked.Synthesis and applications. Altogether, our results indicate that insects and microbes can rapidly remove faeces, with the potential to also decrease the persistence of human pathogens. In turn, this suggests that improved food safety may be an important, and perhaps underappreciated, ecosystem service that is enhanced by on‐farm biodiversity. We recommend that farm managers and regulators consider the risks and benefits to coprophages when making management decisions regarding food safety. Altogether, our results indicate that insects and microbes can rapidly remove faeces, with the potential to also decrease the persistence of human pathogens. In turn, this suggests that improved food safety may be an important, and perhaps underappreciated, ecosystem service that is enhanced by on‐farm biodiversity. We recommend that farm managers and regulators consider the risks and benefits to coprophages when making management decisions regarding food safety. Editor's Choice [ABSTRACT FROM AUTHOR]

A novel foot disease in free-ranging elk (Cervus elaphus) in southwestern Washington State emerged in 2008 and spread throughout the region. Initial studies showed adult elk had chronic hoof overgrowth, sole ulcers, and sloughed hoof capsules, but no cause was determined. To identify possible causes and characterize the earliest lesions, 9-, 7-, and 3-month-old elk were collected. Nine-month-old elk had sole ulcers (3/9 elk) and sloughed/overgrown hoof capsules (4/9 elk) similar to adults. Histologically, lesions consisted of coronary, heel bulb, and interdigital ulcers with suppurative inflammation, epithelial hyperplasia, deeply invasive spirochetes, and underrunning of the hoof capsule and heel-sole junction. Spirochetes were identified as Treponema via immunohistochemistry and polymerase chain reaction (PCR). Seven-month-old elk had similar underrunning foot ulcers (6/8 elk) with Treponema identified in all lesions but no chronic overgrowth or sloughed hoof capsules. Three-month-old calves had superficial coronary erosions with no inflammation or identifiable spirochetes (3/5 elk) but were culture/PCR positive for Treponema, suggesting possible early lesions. Lesions from 9- and 7-month-old elk included aerobic and anaerobic bacteria, many of which are associated with infectious foot disease in livestock. Antibody enzyme-linked immunosorbent assay of 7- and 3-month-old elk from the enzootic region showed a trend toward increased Treponema antibody titers compared to normal control elk from outside the region, further supporting the significance of Treponema in the pathogenesis of foot disease. Treponeme-associated hoof disease (TAHD) in elk, a debilitating and progressive condition, shares similarities to bovine digital dermatitis and contagious ovine digital dermatitis. [ABSTRACT FROM AUTHOR]

To the Editor: Drs. Angulo and Collignon point out that exposure to one antimicrobial drug (e.g., tetracycline) can confer a selective advantage to a multiresistant organism (e.g., R-type ACSSuT) over [...]

The often-noted and persistent increased incidence of Escherichia coli O157:H7 infections in rural areas is not well understood. We used a cohort of E. coli O157:H7 cases reported in Washington, USA, during 2005-2014, along with phylogenomic characterization of the infecting isolates, to identify geographic segregation of and temporal trends in specific phylogenetic lineages of E. coli O157:H7. Kernel estimation and generalized additive models demonstrated that pathogen lineages were spatially segregated during the period of analysis and identified a focus of segregation spanning multiple, predominantly rural, counties for each of the main clinical lineages, Ib, IIa, and IIb. These results suggest the existence of local reservoirs from which humans are infected. We also noted a secular increase in the proportion of lineage IIa and IIb isolates. Spatial segregation by phylogenetic lineage offers the potential to identify local reservoirs and intervene to prevent continued transmission. [ABSTRACT FROM AUTHOR]