Antimicrobial resistance of Escherichia coli from dairy farms participating in an antimicrobial stewardship educational program for farm employees

Antimicrobial use in food-producing animals is under increasing scrutiny due to the potential effect on the selection of antimicrobial-resistant bacteria that may be transmitted to humans by direct contact, with the food chain, or the environment. Novel data monitoring commensal Escherichia coli from dairy farms is essential for understanding antimicrobial resistance (AMR) patterns and their association with herd health management practices. The objectives of this study were to: (1) compare the prevalence of antimicrobial resistance in the E. coli isolates from the hospital, fresh, and mid-lactation pens from 18 conventional dairy farms participating in an educational training program in antimicrobial stewardship practices in California and Ohio, and (2) to characterize the prevalence of antimicrobial resistance of commensal E. coli isolated from pooled fecal pat samples before and 3 mo after participating in the educational training program. Pooled fecal pat samples were collected from the hospital pen, the fresh pen (1 to 5 DIM), and the mid-lactation pens (90 to 150 DIM) on conventional dairies in CA (n = 9) and OH (n = 9). Fecal samples were collected as part of a larger study using a quasi-experimental design that assigned farms to the training intervention group (TG; 6 per state) or the control group (CG; 3 per state). For the TG, farm worker(s) identified as having the task of diagnosis and treatment of adult cows on the farm participated in a training program on antimicrobial stewardship practices. Pooled fecal samples (n = 7) were collected at enrollment and 3 mo after completing the intervention on each of the participating farms (n = 18), followed by culture for E. coli isolation and antimicrobial sensitivity testing using the broth microdilution methodology. Logistic regression models were used to evaluate the association between E. coli antimicrobial resistance patterns with the training intervention and farm-level factors. No effect was observed in the prevalence of resistant isolates between the control and intervention farms after the training was delivered. Isolates from the hospital pens were 2.48 (95% CI: 1.06-6.22, P = 0.03) and 5.61 (95% CI: 1.94-16.91, P < 0.001) times, more likely to be resistant to streptomycin and chloramphenicol, respectively, than isolates from the mid-lactation pens. Our findings indicate there was a higher prevalence of AMR in E. coli associated with the hospital pen within the farm, while the training program for 3 mo did not affect the prevalence of AMR in E. coli on the farms participating in the program. Further research efforts should be conducted to identify factors driving AMR at the pen level, as well as approaches that could be used to reduce the risk of disseminating AMR from sick pens to animals being housed and to other pens on the farm.

Antimicrobial stewardship on the dairy: Evaluating an on-farm framework for training farmworkers

Dairy farmworkers are commonly responsible for disease diagnosis and routine treatment decisions for cattle. This highlights the importance of farmworkers' knowledge and skills to successfully implement judicious use of antimicrobials in livestock production systems. The main objectives of this project were to develop and evaluate an on-farm educational program for farmworkers in antimicrobial stewardship in adult dairy cattle. A longitudinal quasi-experimental study design was used, by enrolling 12 conventional dairy farms in the United States (6 in California and 6 in Ohio). Farmworkers responsible for treatment decisions on the farm (n = 25) participated in a didactic and hands-on 12-wk antimicrobial stewardship training program led by the investigators. All antimicrobial stewardship training materials were available in Spanish and English. Interactive short videos with audio were developed to cover the learning objectives for each of the 6 teaching modules: antimicrobial resistance, treatment protocols, visual identification of sick animals, clinical mastitis, puerperal metritis, and lameness. Pre- and post-training assessments were administered using an online training assessment tool to evaluate changes in knowledge and attitudes about antimicrobial stewardship practices. Cluster analysis and multiple correspondence analyses were conducted to evaluate the association among categorical variables for participants' level of change in knowledge and its association with language, farm size, and state. A 32% average increase in knowledge was observed through an assessment conducted after completing the antimicrobial stewardship training, compared with the pre-training assessment. A significant improvement in 7 of 13 attitude questions related to antimicrobial stewardship practices on the farm was observed. Knowledge and attitude scores of participants on antimicrobial stewardship and identification of sick animals significantly improved after completing the antimicrobial stewardship training. The results observed in this study support the relevance of antimicrobial stewardship training programs targeting farmworkers to improve antimicrobial drug use knowledge and skills.

Optical properties of ZnO nanoparticles on the porous structure of mordenites and ZSM-5

ZnO nanoparticles ranging from 2 to 10 nm were grown on ZSM-5 and mordenite zeolite hosts with different SiO2/Al2O3 molar ratios (MR). Formation of ZnO nanoparticles in the samples was confirmed by TEM. XRD and nitrogen adsorption measurements revealed that the zeolite structure is not destroyed. Surface Zn concentration was calculated from XPS data. ZnO nanoparticles in the zeolite matrix were studied by UV-Vis, diffuse reflectance and cathodoluminescence (CL) spectroscopies. CL revealed three different emissions from ZnO nanoparticles, approximately 3.1, 2.8 and 2.5 eV. The ZnO band-edge emission was associated with blue defects-related and oxygen vacancies emissions. The generation of the point defects at the interface explains the presence of this blue band.

Trapping of BTX compounds by SiO2, Ag-SiO2, Cu-SiO2, and Fe-SiO2 porous substrates

Adsorption isotherms of BTX aromatic hydrocarbons (benzene, toluene, and p-xylene) on pristine (SiO2) and metal-doped (Ag-SiO2, Cu-SiO2 and Fe-SiO2) mesoporous and microporous substrates were measured and interpreted. These adsorbents were synthesized by the sol-gel procedure and their BTX sorption isotherms were obtained by the gas chromatographic technique (GC) at several temperatures in the range 423-593 K. The uptake amount of these hydrocarbon adsorptives on SiO2, Ag-SiO2, Cu-SiO2 and Fe-SiO2 mesoporous and microporous substrates was temperature-dependent. Additionally, the interaction of BTX molecules with the pore walls was evaluated by means of the corresponding isosteric heat of adsorption (qst), which was found to follow the next increasing sequence: qst (benzene)<qst (toluene)<qst (p-xylene). In general, the isosteric heat of adsorption of aromatic BTX compounds on microporous silica depicted an increasing tendency when the amount adsorbed was raised. This was a consequence of the existence of cohesive interactions (adsorbate-adsorbate) besides of the adhesive ones (adsorbate-adsorbent). The inclusion of silver or iron atoms within the SiO2 structure leads to an increased adsorbed amount of BTX molecules on the solid surface if compared with the Cu-SiO2 adsorbent. The adsorption of benzene, but not of toluene and p-xylene, molecules on pristine SiO2 is facilitated by the pore size of this substrate since this is the highest of all materials.

Cardiac Safety Results of a Phase II Trial of Adjuvant Docetaxel/Cyclophosphamide Plus Trastuzumab (Her TC) in HER2+ Early Stage Breast Cancer Patients

Background: Docetaxel/cyclophosphamide (TC) has superior activity to doxorubicin/cyclophosphamide (AC) in the adjuvant treatment of patients (pts) with early breast cancer and is devoid of known cardiac toxicity (Jones et al, JCO 27:1177-1183, 2009). Although the addition of trastuzumab (H) to anthracycline-based adjuvant regimens is effective, it is associated with increased cardiac toxicity. Therefore, a short course of the nonanthracycline TC regimen coupled with H appeared to be a logical combination for women with lower risk HER2+ breast cancer. We report the cardiac safety of the TC+H regimen for the first group of women to complete 1 year of treatment.Patients and Methods: 263 pts were registered to the study and stratified by nodal status (positive/negative). Pts must have had baseline left ventricular ejection fraction (LVEF) ≥50% by MUGA or ECHO. On Day 1 of each 21-day cycle for a total of 4 cycles, pts received: (T) 75 mg/m2 IV, followed by (C) 600 mg/m2 IV. Weekly (H) was also given at 4 mg/kg IV (loading dose, over 90 minutes Day 1, Cycle 1 only) and 2 mg/kg IV Days 1, 8, 15 thereafter throughout chemotherapy. After completion of chemotherapy, H was administered at 6 mg/kg IV every 3 weeks to complete 12 months of therapy with H. Decreased LVEF was defined as a decrease from baseline (start of treatment) to completion of TC+H, or when assessed at 3-month intervals until the completion of H treatment. H was withheld if there was a 15% or more decline in LVEF (absolute %). Treatment was discontinued after 2 or 3 treatment delays at investigator's discretion (same rules as prior studies). This report focuses on cardiac safety occurring during the 3 months of chemotherapy plus 1 year of H therapy.Results: To date, 260 pts completed 1 year of treatment and comprised the cardiac safety population; median age was 55 yrs (30-76); 90% of pts had ECOG 0; 64% were ER+, 47% were PR+, and 77% had no lymph node involvement. 184 pts (70%) completed planned treatment and 23 pts (9%) discontinued treatment due to adverse events. A total of 61 pts (23.5%) had declines of ≥10% LVEF; 8 pts (3.1%) had 2 or more LVEF declines ≥10% and were taken off treatment before 1 year of H was completed, and 16 pts (6.1%) had declines of LVEF below 50% during treatment. No patient had clinical CHF.Scheduled MUGA/ECHO ResultsMonthPatients, no.Median LVEF, % (range)Patients with decrease LVEF ≥10%, no.Patients with LVEF &lt;50%, no.Baseline26064 (49,89)––1-324163 (40,85)154-623062 (40,85)2157-921763 (36,89)265≥1018763 (48,80)131Conclusions: H combined with 4 cycles of the nonanthracycline TC regimen produced a low rate of cardiac events, mainly asymptomatic drops in LVEF, but no reported cases of CHF.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5082.

Chlorobenzene, chloroform, and carbon tetrachloride adsorption on undoped and metal-doped sol-gel substrates (SiO(2), Ag/SiO(2), Cu/SiO(2) and Fe/SiO(2))

Adsorption isotherms of chlorobenzene, chloroform and carbon tetrachloride vapors on undoped SiO(2), and metal-doped Ag/SiO(2), Cu/SiO(2) and Fe/SiO(2) substrates were measured in the temperature range of 398-593K. These substrates were prepared from a typical sol-gel technique in the presence of metal dopants that rendered an assortment of microporous-mesoporous solids. The relevant characteristic of these materials was the different porosities and micropore to mesopore volume ratios that were displayed; this was due to the effect that the cationic metal valence exerts on the size of the sol-gel globules that compose the porous solid. The texture of these SiO(2) materials was analyzed by X-ray diffraction (XRD), FTIR, and diverse adsorption methods. The pore-size distributions of the adsorbents confirmed the existence of mesopores and supermicropores, while ultramicropores were absent. The Freundlich adsorption model approximately fitted the chlorinated compounds adsorption data on the silica substrates by reason of a heterogeneous energy distribution of adsorption sites. The intensity of the interaction between these organic vapors and the surface of the SiO(2) samples was analyzed through evaluation of the isosteric heat of adsorption and standard adsorption energy; from these last results it was evident that the presence of metal species within the silica structure greatly affected the values of both the amounts adsorbed as well as of the isosteric heats of adsorption.