clay and Escherichia-coli-Infections

Two experiments were conducted to determine whether 3 different clays in the nursery diet reduce diarrhea of weaned pigs experimentally infected with a pathogenic Escherichia coli. Weaned pigs (21 d old) were housed in individual pens of disease containment chambers for 16 d [4 d before and 12 d after the first challenge (d 0)]. The treatments were in a factorial arrangement: 1) with or without an E. coli challenge (F-18 E. coli strain; heat-labile, heat-stable, and Shiga-like toxins; 10(10) cfu/3 mL oral dose daily for 3 d from d 0) and 2) dietary treatments. The ADG, ADFI, and G:F were measured for each interval (d 0 to 6, 6 to 12, and 0 to 12). Diarrhea score (DS; 1 = normal; 5 = watery diarrhea) was recorded for each pig daily. Feces were collected on d 0, 3, 6, 9, and 12 and plated on blood agar to differentiate β-hemolytic coliforms (HC) from total coliforms (TC) and on MacConkey agar to verify E. coli. Their populations on blood agar were assessed visually using a score (0 = no growth; 8 = very heavy bacterial growth) and expressed as a ratio of HC to TC scores (RHT). Blood was collected on d 0, 6, and 12 to measure total and differential white blood cell (WBC) counts, packed cell volume (PCV), and total protein (TP). In Exp. 1 (8 treatments; 6 replicates), 48 pigs (6.9 ± 1.0 kg of BW) and 4 diets [a nursery control diet (CON), CON + 0.3% smectite (SM), CON + 0.6% SM, and CON until d 0 and then CON + 0.3% SM] were used. The SM treatments did not affect growth rate of the pigs for the overall period. In the E. coli challenged group, the SM treatments reduced DS for the overall period (1.77 vs. 2.01; P < 0.05) and RHT on d 6 (0.60 vs. 0.87; P < 0.05) and d 9 (0.14 vs. 0.28; P = 0.083), and altered differential WBC on d 6 (neutrophils, 48 vs. 39%, P = 0.092; lymphocytes, 49 vs. 58%, P = 0.082) compared with the CON treatment. In Exp. 2 (16 treatments; 8 replicates), 128 pigs (6.7 ± 0.8 kg of BW) and 8 diets [CON and 7 clay treatments (CON + 0.3% SM, kaolinite, and zeolite individually and all possible combinations to total 0.3% of the diet)] were used. The clay treatments did not affect growth rate of the pigs. In the E. coli challenged group, the clay treatments reduced DS for the overall period (1.63 vs. 3.00; P < 0.05), RHT on d 9 (0.32 vs. 0.76; P < 0.05) and d 12 (0.13 vs. 0.39; P = 0.094), and total WBC on d 6 (15.2 vs. 17.7 × 10(3)/μL; P = 0.069) compared with the control treatment. In conclusion, dietary clays alleviated diarrhea of weaned pig

Topics: Aluminum Silicates; Animal Feed; Animal Husbandry; Animals; Clay; Diarrhea; Diet; Escherichia coli; Escherichia coli Infections; Feces; Female; Male; Swine; Swine Diseases; Weaning

Currently, there are few strategies for controlling pathogenic bacteria, especially the pathotypes of Escherichia coli which are an emerging threat to public health worldwide. Here, multivalent vaccine formulations are reported for control of pathogenic E. coli. The formulations utilised clay nanoparticles, either layered double hydroxides (LDH) or hectorite (HEC), to complex with a cocktail of three recombinant antigens, intimin β (IB), proprietary antigen 1 (PAg1) and proprietary antigen 2 (PAg2). Acting as nano-adjuvants, LDH and HEC were able to stimulate strong, durable and balanced immune responses in mice. Moreover, LDH-IB-PAg1-PAg2 and HEC-IB-PAg1-PAg2 immunised mice developed potent mucosal immune responses and efficiently prevented adherence of enterohemorrhagic E. coli serotype O26 to mammalian cells. Notably, the multi-faceted immune responses elicited by the clay nanoparticle formulations were significantly higher than those induced by a QuilA formulation, without antigenic competition observed for the first time. The results of this study suggest that LDH and HEC offer considerable promise as effective multivalent vaccine carriers against important pathogens such as enteropathogenic E. coli.

Topics: Adhesins, Bacterial; Adsorption; Animals; Antibodies, Bacterial; Antigens, Bacterial; Clay; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Escherichia coli Vaccines; Female; Hydroxides; Immunoglobulin G; Mice, Inbred C57BL; Nanoparticles; Silicates

Development of new functional coatings in the field of health care, as antibacterial applications, deals with a straight control of the diffusive properties that rules the releasing of the active component. In this work, the development of a silver-rich nanocomposite thin coating, loaded with organically modified clay nanoparticles, is presented. The synthesis process included an environment-friendly silanization process of clay nanoparticles (Laponite® S482) with (3-glycidoxypropyl)trimethoxysilane (GPTMS) and the further hydrolytic condensation with tetraethoxysilane (TEOS). Silanization process and the obtained coatings were analysed by Fourier transformed infrared spectroscopy, UV-visible spectroscopy, X-ray diffraction, thermogravimetric curves and scanning electron microscopy. The silanization process of clay nanoparticles with the organically reactive alkyl alkoxysilane, allowed to stabilize and exfoliate the clay nanosheets within a hybrid organic-inorganic sol-gel material. Ring opening of grafted epoxy groups carried to an increasing of the basal spacing, of intercalated clay nanosheets, from 1.3 to 1.8nm. Moreover, incorporation of organically modified clay nanosheets introduced a significant stabilization on the development of silver nanoparticles inside the structure of the nanocomposite coating, retaining the silver inside the coating material and restricting the growing of silver nanoparticles on the surface of the coating. Antibacterial behaviour, against E. coli cultures, performed through agar diffusion tests, provided promising results that allow assuming that the studied nanocomposite coating serves as a reservoir of ionic silver, permitting the antibacterial effect.

Topics: Aluminum Silicates; Anti-Bacterial Agents; Clay; Coated Materials, Biocompatible; Epoxy Compounds; Escherichia coli; Escherichia coli Infections; Humans; Metal Nanoparticles; Nanocomposites; Silicon Dioxide; Silver

In recent decades, diseases caused by pathogenic Escherichia coli (E. coli), enterohaemorrhagic E. coli (EHEC) O26 have been increasingly reported worldwide, which are as severe as those caused by EHEC strain O157:H7 and require effective intervention strategies. Herein, we report the application of clay nanoparticles, i.e. hectorites as effective nano-adjuvants for vaccination against EHEC O26 colonization. We show that medium size HEC (hectorite, around 73~77 nm diameter) is able to induce efficient humoral and cellular immune responses against EHEC antigen - intimin β (IB), which are significantly higher than those triggered by commercially used adjuvants - QuilA and Alum. We also demonstrate that mice immunized with IB adjuvanted with HEC nanoparticles elicit sufficient secretion of mucosal IgA, capable of providing effective protection against EHEC O26 binding to ruminant and human cells. In addition, we demonstrate for the first time that hectorites are able to initiate maturation of RAW 264.7 macrophages, inducing expression of co-stimulatory cytokines at a low nanoparticle concentration (10 μg/mL). Together these data strongly suggest that hectorite with optimized size is a highly efficient vaccine nano-adjuvant.

Topics: Adjuvants, Immunologic; Adsorption; Animals; Chemical Phenomena; Clay; Escherichia coli Infections; Escherichia coli O157; Escherichia coli Proteins; Humans; Immunity, Cellular; Immunization; Intestinal Mucosa; Macrophages; Mice; Nanoparticles

To investigate the mechanisms leading to an increase in the prevalence of blaCMY -2 conferring resistance to ceftiofur in pigs receiving a feed medicated with chlortetracycline and penicillin, and to examine the effect of supplementation with a clay mineral on this phenomenon.. In 138 blaCMY -2 -positive Escherichia coli isolates from faeces of pigs receiving feed supplemented or not with 2% clinoptilolite, from day 2 to day 28 after weaning, isolates from the two groups differed significantly with respect to their phylogenetic group: phylotype A predominated in the supplemented group, whereas phylotypes B1 and D predominated in the control group, as determined by PCR. In 36 representative isolates, pulsed-field gel electrophoresis and antimicrobial susceptibility testing revealed that the blaCMY -2 -positive E. coli isolates were polyclonal with diverse antimicrobial resistance patterns and blaCMY -2 -carrying plasmids of incompatibility (Inc) groups, A/C, I1 and ColE were observed in transformants as detected by PCR. Enterobacter cloacae possessing blaCMY -2 -carrying IncA/C plasmids were found in the pens before introduction of this batch of pigs. The blaCMY -2 -positive E. coli isolates were more clonally diverse in the control group than the supplemented group.. The blaCMY -2 gene appears to have spread both horizontally and clonally in this batch of pigs and may have spread from previous batches of pigs via plasmids carried by Ent. cloacae and expanded in animals of the present batch in the presence of the selection pressure due to administration of chlortetracycline and penicillin in the feed. Feed supplementation may have an effect on clonal diversity of blaCMY -2 -positive isolates.. Implementation of improved hygiene measures, decreased administration of certain antimicrobials on farm and feed supplementation with certain ingredients may limit antimicrobial resistance spread between and within batches of animals.

Topics: Aluminum Silicates; Animal Feed; Animals; Anti-Bacterial Agents; beta-Lactamases; Cephalosporins; Chlortetracycline; Clay; Dietary Supplements; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Escherichia coli; Escherichia coli Infections; Escherichia coli Proteins; Farms; Feces; Phylogeny; Plasmids; Swine; Swine Diseases; Weaning

The survival of Escherichia coli O157:H7 in replicate soil microcosms was quantified in 2 types of silty clay loam soil (high carbon and low carbon) under either sterile or nonsterile conditions. Microcosms were held at -21, 4, and 22 degrees C under constant soil moisture content. Differences existed (P < 0.05) in survival of E. coli O157:H7 in low- and high-carbon soil at all temperatures, indicating an important role of soil composition on the survival of this pathogen. The highest death rate of E. coli O157:H7 in sterile soil occurred in the low-carbon soil at 4 degrees C, whereas in nonsterile soil the highest death rate was observed in the low-carbon soil at 22 degrees C. These results suggest that the most lethal effects on E. coli O157:H7 in the sterile system occurred via the synergy of nutrient limitation and cold stress, whereas in the nonsterile system lethality was owing to inhibition by indigenous soil microorganisms and starvation. Results obtained from an in situ field survival experiment demonstrated the apparent sensitivity of E. coli O157:H7 cells to dehydration, information that may be used to reduce environmental spread of this pathogen as well as formulate appropriate waste management strategies.

Topics: Aluminum Silicates; Animals; Cattle; Cattle Diseases; Clay; Environment; Escherichia coli Infections; Escherichia coli O157; Manure; Soil; Soil Microbiology; Temperature

A pilot study was carried out on a Danish swine farm infected with multi-resistant Salmonella Typhimurium DT104 (MRDT104). We aimed to (1) investigate to which degree the decline of Escherichia coli and Salmonella in swine slurry applied to farmland depended on the application method; (2) estimate the survival times of E. coli and Salmonella in the soil surface following deposition of naturally contaminated pig slurry; and (3) simulate survival of Salmonella in different infection levels using E. coli data as input estimates. Slurry was deposited by four different methods: (1) hose applicator on black soil followed by ploughing and harrowing; (2) hose applicator on black soil followed only by harrowing; (3) hose applicator on a field with winter-wheat seedlings without further soil treatment; (4) slurry injector on a field with winter-wheat seedlings without further soil treatment. E. coli and Salmonella could not be detected at all in soil following treatment 1. Following the other treatments, E. coli was not detected in soil samples after day 21 and Salmonella was no longer detected after day 7. Simulation results showed that clinical (4 log CFU g(-1)) and sub-clinical Salmonella levels (2500 CFU g(-1)) would fall below the detection limit within 10 or 5 days, respectively. Analysis of samples from 62 Danish MRDT104-infected swineherds showed that nearly 75% of these herds had low levels of MRDT104 (< 10 CFU g(-1)) in their slurry. Our results show that ploughing and harrowing of soil amended with contaminated pig slurry was an effective means to reduce environmental exposure to E. coli and Salmonella on this clay-soil farm.

Topics: Aluminum Silicates; Animals; Clay; Computer Simulation; Denmark; Escherichia coli; Escherichia coli Infections; Manure; Models, Biological; Pilot Projects; Salmonella Infections, Animal; Salmonella typhimurium; Soil Microbiology; Swine