Abstract The objective of this experiment was to investigate the effects of Bacillus subtilis on growth performance, diarrhea and fecal β-hemolytic coliforms of weaned pigs experimentally infected with a strain of E. coli (F18, express genes of LT, STb, and SLT 2 toxins). Weaned pigs (n = 48, 6.17 ± 0.36 kg BW) were individually housed in disease containment rooms and randomly allotted to one of four dietary treatments: negative control (NC, control diet without E. coli challenge), positive control (PC, control diet with E. coli challenge), and supplementation of 50 mg/kg of carbadox or 500 mg/kg of Bacillus subtilis probiotics. The experiment lasted 28 d with 7 d before and 21 d after the first E. coli inoculation. The F18 E. coli were given to pigs at 1010 CFU/3 mL dose for three consecutive d. Diarrhea score was daily recorded for each pig to calculate frequency of diarrhea. Fecal samples were collected on d 0, 3, 7, 14, and 21 PI to analyze β-hemolytic coliforms. Data were analyzed using the Mixed Procedure of SAS. Pigs supplemented with carbadox had greater (P < 0.05) body weight on d 7, 14, and 21 PI than pigs in the PC and probiotics group. Supplementation of probiotics enhanced pig body weight on d 21 PI, compared with the PC. E. coli challenge reduced (P < 0.05) ADG and feed efficiency from d 0 to 21 PI, while supplementation of antibiotics or probiotics enhanced ADG and feed efficiency from d 0 to 21 PI. Pigs in carbadox and probiotics groups had reduced (P < 0.05) frequency of diarrhea throughout the experiment and fecal β-hemolytic coliforms on d 7 PI than pigs in the PC. In conclusion, supplementation of Bacillus subtilis could enhance disease resistance and promote growth performance of weaned pigs under disease challenge condition.
This study measured the inactivation rate of bovine genotype A Cryptosporidium parvum oocysts attributable to diurnal oscillations of ambient temperature and solar radiation typical of California rangelands and dairies from spring through autumn. We first measured the relationship between air temperature and the internal temperature of bovine feces exposed to sunlight on commercial operations throughout California. Once maximum air temperature exceeded the mid 20 °C, diurnal thermal regimes of bovine fecal material exhibited peaks of over 40, 50, 60, and 70 °C. These diurnal thermal regimes were emulated using a thermocycler, with oocysts suspended in distilled water or fecal−water mix. Using oral inoculations of 105 C. parvum oocysts per neonatal Balb/c mouse (>1000-fold the ID50), no infections were observed using 1 to 5-day cycles of these thermal regimes. Loss of infectivity induced by these thermal regimes was primarily due to partial or complete in vitro excystation during the first 24-h diurnal cycle and secondarily to thermal inactivation of the remaining intact or partial oocysts. These results suggest that as ambient conditions generate internal fecal temperatures ≥40 °C via conduction, radiation, and convection, rapid environmental inactivation occurs at a rate of ≥3.27 log reduction d-1 for C. parvum oocysts deposited in the feces of cattle.
Abstract The objective of this experiment was to investigate dietary supplementation of oligosaccharide-based polymer on growth performance, diarrhea, and fecal β-hemolytic coliforms of weaned pigs experimentally infected with a pathogenic F18 Escherichia coli (E. coli). Forty-eight pigs (7.23 ± 1.11 kg BW) were individually housed in disease containment rooms and randomly allotted to one of four treatments with 12 replicate pigs per treatment. The four dietary treatments were a nursery basal diet (control), and 3 additional diets supplemented with 50 mg/kg Mecadox (AGP), 10 or 20 mg/kg of oligosaccharide-based polymer. The experiment lasted 18 d [7 d before and 11 d after the first inoculation (d 0)]. The doses of F18 E. coli inoculum were 1010 cfu/3 mL oral dose daily for 3 days. Growth performance was measured on d -7 to 0 before inoculation, and d 0 to 5 and 5 to 11 post-inoculation (PI). Diarrhea score (DS; 1, normal, to 5, watery diarrhea) was daily recorded for each pig. Fecal samples were collected on d 2, 5, 8, and 11 PI to test the percentage of β-hemolytic coliforms in total coliforms. All data were analyzed by ANOVA using the PROC MIXED of SAS with pig as the experimental unit. Inclusion of oligosaccharide-based polymer linearly increased (P < 0.05) ADFI on d 0 to 5 PI, and feed efficiency on d 0 to 5 PI and d 5 to 11 PI (P = 0.07), compared with the control. Supplementation of AGP or oligosaccharide-based polymer reduced (P < 0.01) frequency of diarrhea of pigs from d 0 to 11 PI. No differences were observed in overall growth performance and percentage of fecal β-hemolytic coliforms on d 8 PI among pigs in AGP and oligosaccharide-based polymer treatments. In conclusion, supplementation of oligosaccharide-based polymer enhanced feed efficiency and reduced diarrhea of weaned pigs infected with a pathogenic E. coli.
Abstract The objective of this experiment was to investigate dietary supplementation of oligosaccharide-based polymer on blood profiles of weaned pigs experimentally infected with a pathogenic F18 Escherichia coli (E. coli). Forty-eight pigs (7.23 ± 1.11 kg BW) were individually housed in disease containment rooms and randomly allotted to one of four treatments with 12 replicate pigs per treatment. The four dietary treatments were a nursery basal diet (control), and 3 additional diets supplemented with 50 mg/kg Mecadox (AGP), 10 or 20 mg/kg of oligosaccharide-based polymer. The experiment lasted 18 d [7 d before and 11 d after the first inoculation (d 0)]. The doses of F18 E. coli inoculum were 1010 cfu/3 mL oral dose daily for 3 days. Blood samples were collected before E. coli inoculation (d 0), and on d 2, 5, 8, and 11 post-inoculation (PI). Total and differential blood cell count were analyzed by CBC test. All data were analyzed by ANOVA using the PROC MIXED of SAS with pig as the experimental unit. Supplementation of oligosaccharide-based polymer linearly (P < 0.05) reduced white blood cell counts, neutrophils, eosinophils, and basophils on d 2 PI, and neutrophils on d 5 PI, compared with the control. No differences were observed in total and differential white blood cell counts among AGP and two oligosaccharide-based polymer treatments except that pigs fed with AGP had greater (P < 0.05) lymphocytes on d 2 PI compared with pigs fed with oligosaccharide-based polymer diets. Supplementation of low dose oligosaccharide-based polymer or AGP reduced (P < 0.05) red blood cell count and packed cell volume on d 2 PI, whereas inclusion of high dose oligosaccharide-based polymer or AGP reduced (P < 0.05) packed cell volume on d 5 PI, compared with the control. In conclusion, supplementation of oligosaccharide-based polymer may alleviate the systemic inflammation caused by F18 E. coli infection.
Retail meat products may serve as reservoirs and conduits for antimicrobial resistance, which is frequently monitored using Escherichia coli as indicator bacteria. In this study, E. coli isolation was conducted on 221 retail meat samples (56 chicken, 54 ground turkey, 55 ground beef, and 56 pork chops) collected over a one-year period from grocery stores in southern California. The overall prevalence of E. coli in retail meat samples was 47.51% (105/221), with E. coli contamination found to be significantly associated with meat type and season of sampling. From antimicrobial susceptibility testing, 51 isolates (48.57%) were susceptible to all antimicrobials tested, 54 (51.34%) were resistant to at least 1 drug, 39 (37.14%) to 2 or more drugs, and 21 (20.00%) to 3 or more drugs. Resistance to ampicillin, gentamicin, streptomycin, and tetracycline were significantly associated with meat type, with poultry counterparts (chicken or ground turkey) exhibiting higher odds for resistance to these drugs compared to non-poultry meats (beef and pork). From the 52 E. coli isolates selected to undergo whole-genome sequencing (WGS), 27 antimicrobial resistance genes (ARGs) were identified and predicted phenotypic AMR profiles with an overall sensitivity and specificity of 93.33% and 99.84%, respectively. Clustering assessment and co-occurrence networks revealed that the genomic AMR determinants of E. coli from retail meat were highly heterogeneous, with a sparsity of shared gene networks.
Background Understanding the effects of herd management practices on the prevalence of multidrug-resistant pathogenic Salmonella and commensals Enterococcus spp. and Escherichia coli in dairy cattle is key in reducing antibacterial resistant infections in humans originating from food animals. Our objective was to explore the herd and cow level features associated with the multi-drug resistant, and resistance phenotypes shared between Salmonella , E. coli and Enterococcus spp. using machine learning algorithms. Methods Randomly collected fecal samples from cull dairy cows from six dairy farms in central California were tested for multi-drug resistance phenotypes of Salmonella, E. coli and Enterococcus spp. Using data on herd management practices collected from a questionnaire, we built three machine learning algorithms (decision tree classifier, random forest, and gradient boosting decision trees) to predict the cows shedding multidrug-resistant Salmonella and commensal bacteria. Results The decision tree classifier identified rolling herd average milk production as an important feature for predicting fecal shedding of multi-drug resistance in Salmonella or commensal bacteria. The number of culled animals, monthly culling frequency and percentage, herd size, and proportion of Holstein cows in the herd were found to be influential herd characteristics predicting fecal shedding of multidrug-resistant phenotypes based on random forest models for Salmonella and commensal bacteria. Gradient boosting models showed that higher culling frequency and monthly culling percentages were associated with fecal shedding of multidrug resistant Salmonella or commensal bacteria. In contrast, an overall increase in the number of culled animals on a culling day showed a negative trend with classifying a cow as shedding multidrug-resistant bacteria. Increasing rolling herd average milk production and spring season were positively associated with fecal shedding of multidrug- resistant Salmonella . Only six individual cows were detected sharing tetracycline resistance phenotypes between Salmonella and either of the commensal bacteria. Discussion Percent culled and culling rate reflect the increase in culling over time adjusting for herd size and were associated with shedding multidrug resistant bacteria. In contrast, number culled was negatively associated with shedding multidrug resistant bacteria which may reflect producer decisions to prioritize the culling of otherwise healthy but low-producing cows based on milk or beef prices (with respect to dairy beef), amongst other factors. Using a data-driven suite of machine learning algorithms we identified generalizable and distant associations between antimicrobial resistance in Salmonella and fecal commensal bacteria, that can help develop a producer-friendly and data-informed risk assessment tool to reduce shedding of multidrug-resistant bacteria in cull dairy cows.
Surveys of microbiological groundwater quality were conducted in a region with intensive animal agriculture in California, USA. The survey included monitoring and domestic wells in eight concentrated animal feeding operations (CAFOs) and 200 small (domestic and community supply district) supply wells across the region. Campylobacter was not detected in groundwater, whereas Escherichia coli O157:H7 and Salmonella were each detected in 2 of 190 CAFO monitoring well samples. Nonpathogenic generic E. coli and Enterococcus spp. were detected in 24.2% (46/190) and 97.4% (185/190) groundwater samples from CAFO monitoring wells and in 4.2% (1/24) and 87.5% (21/24) of CAFO domestic wells, respectively. Concentrations of both generic E. coli and Enterococcus spp. were significantly associated with well depth, season, and the type of adjacent land use in the CAFO. No pathogenic bacteria were detected in groundwater from 200 small supply wells in the extended survey. However, 4.5 to 10.3% groundwater samples were positive for generic E. coli and Enterococcus. Concentrations of generic E. coli were not significantly associated with any factors, but concentrations of Enterococcus were significantly associated with proximity to CAFOs, seasons, and concentrations of potassium in water. Among a subset of E. coli and Enterococcus isolates from both surveys, the majority of E. coli (63.6%) and Enterococcus (86.1%) isolates exhibited resistance to multiple (≥3) antibiotics. Findings confirm significant microbial and antibiotic resistance loading to CAFO groundwater. Results also demonstrate significant attenuative capacity of the unconfined alluvial aquifer system with respect to microbial transport. Core Ideas Systemic surveys of groundwater microbiological quality are performed at site and regional scales. Confined animal systems are chronic sources of pathogens and high enteric microbial loads. Pathogen loading to groundwater is effectively mitigated by alluvial aquifer system. Some microbial indicators are too ubiquitous to be useful as indicators. Antibiotic resistance from CAFOs and human sources affects the alluvial aquifer system.
Climate change produces extremes in both temperature and precipitation causing increased drought severity and increased reliance on groundwater resources. Agricultural practices, which rely on groundwater, are sensitive to but also sources of contaminants, including nitrate. How agricultural contamination drives groundwater geochemistry through microbial metabolism is poorly understood.On an active cow dairy in the Central Valley of California, we sampled groundwater from three wells at depths of 4.3 m (two wells) and 100 m (one well) below ground surface (bgs) as well as an effluent surface water lagoon that fertilizes surrounding corn fields. We analyzed the samples for concentrations of solutes, heavy metals, and USDA pathogenic bacteria of the Escherichia coli and Enterococcus groups as part of a long term groundwater monitoring study. Whole metagenome shotgun sequencing and assembly revealed taxonomic composition and metabolic potential of the community.Elevated nitrate and dissolved organic carbon occurred at 4.3m but not at 100m bgs. Metagenomics confirmed chemical observations and revealed several Planctomycete genomes, including a new Brocadiaceae lineage and a likely Planctomycetes OM190, as well novel diversity and high abundance of nano-prokaryotes from the Candidate Phyla Radiation (CPR), the Diapherotrites, Parvarchaeota, Aenigmarchaeota, Nanoarchaeota, Nanohaloarchaea (DPANN) and the Thaumarchaeota, Aigarchaeota, Crenarchaeota, Korarchaeota (TACK) superphyla. Pathway analysis suggests community interactions based on complimentary primary metabolic pathways and abundant secondary metabolite operons encoding antimicrobials and quorum sensing systems.The metagenomes show strong resemblance to activated sludge communities from a nitrogen removal reactor at a wastewater treatment plant, suggesting that natural bioremediation occurs through microbial metabolism. Elevated nitrate and rich secondary metabolite biosynthetic capacity suggest incomplete remediation and the potential for novel pharmacologically active compounds.
The use of antibiotics in animal production are widely used for disease treatment, health protection, and as growth promoters. Common antibiotics used in veterinary medicine are excreted and eliminated through the sewage system, contaminating water and soil with negative effects on agricultural activities. This systematic review focuses on the trend of research works on antibiotic residues, evaluating antibiotics used in livestock production and their excretion in animal products and in environmental matrices such as water and soil. Our database was composed of 165 articles, reporting the concentration of antibiotic residues found in the environment, livestock (cow, sheep, pig, horse, chicken, rabbit, goat), aquatic and terrestrial animal tissues, animal products (milk and eggs), wastewater, and soil. The documents were obtained from Asia, Africa, North America, South America, Europe, and Oceania. A descriptive analysis of antibiotic residues found worldwide was analyzed according to each of the variables used such as antibiotic family, name, concentration (% and mg/kg or ppm), and country and continent where the residue was found. The descriptive analysis was carried out using the "describe" function of psych package and pirate plots were drawn. According to our study, the main antibiotics used worldwide in animal production are sulfonamides, tetracyclines, quinolones, penicillin, and cephalosporins. At present, despite the trends of increased regulations on the use of antibiotics worldwide, antibiotics are still utilized in food animal production, and are present in water and soil, then, there is still the misuse of antibiotics in many countries. We need to become aware that antibiotic contamination is a global problem, and we are challenged to reduce and improve their use.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)
