Synthesis and Characterization of a Sustained Nitric Oxide-Releasing Orthodontic Elastomeric Chain for Antimicrobial Action.

The acidic byproducts of bacteria in plaque around orthodontic brackets contribute to white spot lesion (WSL) formation. Nitric oxide (NO) has antibacterial properties, hindering biofilm formation and inhibiting the growth of oral microbes. Materials that mimic NO release could prevent oral bacteria-related pathologies. This study aims to integrate S-nitroso-acetylpenicillamine (SNAP), a promising NO donor, into orthodontic elastomeric ligatures, apply an additional polymer coating, and evaluate the NO-release kinetics and antimicrobial activity against Streptococus mutans. SNAP was added to clear elastomeric chains (8 loops, 23 mm long) at three concentrations (50, 75, 100 mg/mL, and a control). Chains were then coated, via electrospinning, with additional polymer (Elastollan®) to aid in extending the NO release. NO flux was measured daily for 30 days. Samples with 75 mg/mL SNAP + Elastollan® were tested against S. mutans for inhibition of biofilm formation on and around the chain. SNAP was successfully integrated into ligatures at each concentration. Only the 75 mg/mL SNAP chains maintained their elasticity. After polymer coating, samples exhibited a significant burst of NO on the first day, exceeding the machine's reading capacity, which gradually decreased over 29 days. Ligatures also inhibited S. mutans growth and biofilm formation. Future research will assess their mechanical properties and cytotoxicity. This study presents a novel strategy to address white spot lesion (WSL) formation and bacterial-related pathologies by utilizing nitric oxide-releasing materials. Manufactured chains with antimicrobial properties provide a promising solution for orthodontic challenges, showing significant potential for academic-industrial collaboration and commercial viability.

Conjugated Linoleic Acid-Mediated Connexin-43 Remodeling and Sudden Arrhythmic Death in Myocardial Infarction.

Connexin 43 (Cx43) is expressed in the left and right ventricles and is primarily responsible for conducting physiological responses in microvasculature. Studies have demonstrated that NADPH oxidase (NOX) enzymes are essential in cardiac redox biology and are responsible for the generation of reactive oxygen species (ROS). NOX2 is linked to left ventricular remodeling following myocardial infarction (MI). It was hypothesized that conjugated linoleic acid (cLA) treatment increases NOX-2 levels in heart tissue and disrupts connexins between the myocytes in the ventricle. Data herein demonstrate that cLA treatment significantly decreases survival in a murine model of MI. The observance of cLA-induced ventricular tachyarrhythmia's (VT) led to the subsequent investigation of the underlying mechanism in this MI model. Mice were treated with cLA for 12 h, 24 h, 48 h, or 72 h to determine possible time-dependent changes in NOX and Cx43 signaling pathways in isolated left ventricles (LV) extracted from cardiac tissue. The results suggest that ROS generation, through the stimulation of NOX2 in the LV, triggers a decrease in Cx43 levels, causing dysfunction of the gap junctions following treatment with cLA. This cascade of events may initiate VT and subsequent death during MI. Taken together, individuals at risk of MI should use caution regarding cLA consumption.

Comparison of SIREN social needs screening tools and Simplified Omaha System Terms: informing an informatics approach to social determinants of health assessments.

OBJECTIVE: Numerous studies indicate that the social determinants of health (SDOH), conditions in which people work, play, and learn, account for 30%-55% of health outcomes. Many healthcare and social service organizations seek ways to collect, integrate, and address the SDOH. Informatics solutions such as standardized nursing terminologies may facilitate such goals. In this study, we compared one standardized nursing terminology, the Omaha System, in its consumer-facing form, Simplified Omaha System Terms (SOST), to social needs screening tools identified by the Social Interventions Research and Evaluation Network (SIREN). MATERIALS AND METHODS: Using standard mapping techniques, we mapped 286 items from 15 SDOH screening tools to 335 SOST challenges. The SOST assessment includes 42 concepts across 4 domains. We analyzed the mapping using descriptive statistics and data visualization techniques. RESULTS: Of the 286 social needs screening tools items, 282 (98.7%) mapped 429 times to 102 (30.7%) of the 335 SOST challenges from 26 concepts in all domains, most frequently from Income, Home, and Abuse. No single SIREN tool assessed all SDOH items. The 4 items not mapped were related to financial abuse and perceived quality of life. DISCUSSION: SOST taxonomically and comprehensively collects SDOH data compared to SIREN tools. This demonstrates the importance of implementing standardized terminologies to reduce ambiguity and ensure the shared meaning of data. CONCLUSIONS: SOST could be used in clinical informatics solutions for interoperability and health information exchange, including SDOH. Further research is needed to examine consumer perspectives regarding SOST assessment compared to other social needs screening tools.

Green Processing, Germinating and Wet Milling Brown Rice (Oryza sativa) for Beverages: Physicochemical Effects.

Plant-based beverage consumption is increasing markedly. Value-added dehulled rice (Oryza sativa) germination was investigated to improve beverage qualities. Germinating brown rice has been shown to increase health-promoting compounds. Utilizing green processing, wholesome constituents, including bran, vitamins, minerals, oils, fiber and proteins should should convey forward into germinated brown rice beverages. Rapid visco-analyzer (RVA) data and trends established that brown rice, preheated brown rice and germinated brown rice had higher pasting temperatures than white rice. As pasting temperature in similar samples may be related to gelatinization, RVA helped guide the free-flowing processing protocol using temperatures slightly above those previously reported for Rondo gelatinization. Particle size analysis and viscometric evaluations indicate that the developed sprouted brown rice beverage is on track to have properties close to commercial samples, even though the sprouted brown rice beverage developed has no additives, fortifications, added oils or salts. Phenolics and γ-aminobutyric acid increased slightly in germinated brown rice, however, increases were not maintained throughout most stages of processing. Significantly lower inorganic arsenic levels (113 ng/g) were found in germinated (sprouted) brown rice, compared to Rondo white and brown rice, which is far below the USA threshold level of 200 ng/g.

Understanding the causes of calcium carbonate crystal growth and inhibition during the carbonatation refining of raw sugars.

The inhibitory activity of soluble and insoluble starch (0-550 ppm/Brix) in factory raw sugars were investigated using simulated refinery carbonatation clarification reactions to underpin what causes the undesirable formation of CaCO3 crystal fines (≤5 µm). It was found that CaCO3 crystal growth was inhibited mostly by soluble starch by forming starch-Ca2+ metal complexes. Insoluble (granular) starch, however, had a greater affinity for inhibiting CaCO3 crystallization because it retained the carbonatation clarification reactants, i.e., Ca2+and OH-, in the granule interior which caused granule gelatinization and increased viscosity of the melt liquor. Causes for poor press filterability and CaCO3 fines using raw sugar melts were found to be complex and attributed to the combinatorial roles that both soluble and insoluble starch have, among other impurities. More studies are now warranted at the carbonatation refinery to correlate processing characteristics with raw sugars quality attributes to underpin how each impurity impedes carbonatation.

Comparison of international methods for the determination of total starch in raw sugars: Part II.

Industrial starch methods in the sugar industry are affected by sugarcane- and processing-derived colourants, and it was presumed that these methods are mathematically equatable. Using the USDA Starch Research method as a reference and factory raw sugars, the impact of colourants on the accuracy, precision, limits of detection/quantification, and mathematical equatability of the starch methods were investigated. Approximately 26-55% of raw sugar colour contributed to starch-I3- absorbance. The exclusion of a colour blank negatively affected method accuracy and the addition of a colour blank confirmed that these methods measured mostly colour instead of starch. Inefficient starch solubilization and the inability to standardize sugar colourants explained why starch results from these methods could not be mathematically equated to the USDA Starch Research method, or among different methods. An industrial starch method that efficiently solubilizes starch and includes a colour blank is urgently needed.

MicroRNAs as predictive biomarkers for myocardial injury in aged mice following myocardial infarction.

The occurrence of myocardial infarction (MI) increases appreciably with age. In the Framingham Heart Study, the incidence of MI more than doubles for men and increases more than five-fold in women (ages 55-64 years compared to 85-94 years). MicroRNAs (miRNAs) quantitatively regulate their target's expression post-transcriptionally by either silencing action through binding at the 3'UTR domains or degrading the messages at their coding regions. In either case, these regulations affect the cardiac transcriptional output and cardiac function. Among the known cardiac associated miRNA, miRNA-1, miRNA-133a, and miRNA-34a have been shown to induce adverse structural remodeling to impair cardiac contractile function. In the present study, an in vivo model of MI in young (3 month) and old (22 month) mice is used to investigate the possible role whereby these three miRNAs exert negative effects on heart function following MI. Herein we demonstrate that in older mouse heart, all three microRNAs show increased levels of expression, while miRNA-1 shows a further increase in old mouse heart following MI, which corresponds to left ventricular (LV) wall thinning. These structural changes in cardiac tissue may causes downstream LV dilation and subsequent LV dysfunction. Results presented here suggest that significantly elevated levels of miRNA-1 in post-MI old heart could be predictive of cardiac injury in older mice as the high risk biomarker for MI in older individuals.

Analytical evaluation of current starch methods used in the international sugar industry: Part I.

Several analytical starch methods exist in the international sugar industry to mitigate starch-related processing challenges and assess the quality of traded end-products. These methods use iodometric chemistry, mostly potato starch standards, and utilize similar solubilization strategies, but had not been comprehensively compared. In this study, industrial starch methods were compared to the USDA Starch Research method using simulated raw sugars. Type of starch standard, solubilization approach, iodometric reagents, and wavelength detection affected total starch determination in simulated raw sugars. Simulated sugars containing potato starch were more accurately detected by the industrial methods, whereas those containing corn starch, a better model for sugarcane starch, were only accurately measured by the USDA Starch Research method. Use of a potato starch standard curve over-estimated starch concentrations. Among the variables studied, starch standard, solubilization approach, and wavelength detection affected the sensitivity, accuracy/precision, and limited the detection/quantification of the current industry starch methods the most.

Nuclear respiratory factor-1 and bioenergetics in tamoxifen-resistant breast cancer cells.

Acquired tamoxifen (TAM) resistance is a significant clinical problem in treating patients with estrogen receptor α (ERα)+ breast cancer. We reported that ERα increases nuclear respiratory factor-1 (NRF-1), which regulates nuclear-encoded mitochondrial gene transcription, in MCF-7 breast cancer cells and NRF-1 knockdown stimulates apoptosis. Whether NRF-1 and target gene expression is altered in endocrine resistant breast cancer cells is unknown. We measured NRF-1and metabolic features in a cell model of progressive TAM-resistance. NRF-1 and its target mitochondrial transcription factor A (TFAM) were higher in TAM-resistant LCC2 and LCC9 cells than TAM-sensitive MCF-7 cells. Using extracellular flux assays we observed that LCC1, LCC2, and LCC9 cells showed similar oxygen consumption rate (OCR), but lower mitochondrial reserve capacity which was correlated with lower Succinate Dehydrogenase Complex, Subunit B in LCC1 and LCC2 cells. Complex III activity was lower in LCC9 than MCF-7 cells. LCC1, LCC2, and LCC9 cells had higher basal extracellular acidification (ECAR), indicating higher aerobic glycolysis, relative to MCF-7 cells. Mitochondrial bioenergetic responses to estradiol and 4-hydroxytamoxifen were reduced in the endocrine-resistant cells compared to MCF-7 cells. These results suggest the acquisition of altered metabolic phenotypes in response to long term antiestrogen treatment may increase vulnerability to metabolic stress.

Conjugated linoleic acid and nitrite attenuate mitochondrial dysfunction during myocardial ischemia.

Cardiovascular health is influenced by dietary composition and the western diet is composed of varying types/amounts of fat. Conjugated linoleic acid (cLA) is an abundant dietary unsaturated fatty acid associated with health benefits but its biological signaling is not well understood. Nitrite is enriched in vegetables within the diet and can impact signaling of unsaturated fatty acids; however, its role on cLA signaling is not well understood. Elucidating how nitrite may impact the biological signaling of cLA is important due to the dietary consumption of both cLA and nitrite in the western diet. Since co-administration of cLA and nitrite results in cardioprotection during myocardial infarction (MI), it was hypothesized that cLA and nitrite may affect cardiac mitochondrial respiratory function and complex activity in MI. C57BL/6J mice were treated with cLA and nitrite for either 10 or 13days, where MI was induced on day 3. Following treatment, respiration and complex activity were measured. Among the major findings of this study, cLA treatment (10days) decreases state 3 respiration in vivo. Following MI, nitrite alone and in combination with cLA attenuates increased state 3 respiration and decreases hydrogen peroxide levels. Further, nitrite and cLA co-treatment attenuates increased complex III activity after MI. These results suggest that cLA, nitrite and the combination significantly alter cardiac mitochondrial respiratory and electron transport chain activity in vivo and following MI. Overall, the daily consumption of cLA and nitrite in the diet can have diverse cardiovascular implications, some of which occur at the mitochondrial level.

Development of an analytical method to measure insoluble and soluble starch in sugarcane and sweet sorghum products.

A rapid research method using microwave-assisted probe ultrasonication was developed to quantify total, insoluble, and soluble starch in various sugar crop products. Several variables affecting starch solubilisation were evaluated, (1) heating method, (2) boiling time, (3) probe ultrasonication time, (4) water loss, (5) concentration, (6) sample colour, and (7) sample. The optimised method solubilises < 40,000 ppm insoluble starch with microwave-assisted sonication in 6 min, has acceptable precision (<6% CV), accuracy (⩾ 95%), uses a corn starch reference, and incorporates a colour blank to remove contribution from natural colourants found in industrial samples. This method was validated using factory samples and found applicable to sugarcane and sweet sorghum bagasse (3% CV), mixed juices (2%), massecuites (4%), molasses (7%), and raw sugars (12%), 100% satisfactory performance z-scores were also obtained. Total starch values obtained with this method were significantly higher than those measured using other methods presently accepted by the sugar industry.

Loss of protein targeting to glycogen sensitizes human hepatocellular carcinoma cells towards glucose deprivation mediated oxidative stress and cell death.

Protein targeting to glycogen (PTG) is a ubiquitously expressed scaffolding protein that critically regulates glycogen levels in many tissues, including the liver, muscle and brain. However, its importance in transformed cells has yet to be explored in detail. Since recent studies have demonstrated an important role for glycogen metabolism in cancer cells, we decided to assess the effect of PTG levels on the ability of human hepatocellular carcinoma (HepG2) cells to respond to metabolic stress. Although PTG expression did not significantly affect the proliferation of HepG2 cells under normal culture conditions, we determined that PTG plays an important role during glucose deprivation. Overexpression of PTG protected cells from cell death in the absence of glucose, whereas knocking down PTG further promoted cytotoxicity, as measured by the release of lactate dehydrogenase (LDH) into the media. Additionally, we demonstrated that PTG attenuates glucose deprivation induced haeme oxygenase-1 (HO-1) expression, suggesting that PTG protects against glucose deprivation-induced oxidative stress. Indeed, treating cells with the antioxidant N-acetyl cysteine (NAC) rescued cells from cytotoxicity caused by glucose deprivation. Finally, we showed that loss of PTG resulted in enhanced autophagy. In control cells, glucose deprivation suppressed autophagy as determined by the increase in the levels of p62, an autophagy substrate. However, in knockdown cells, this suppression was relieved. Blockade of autophagy also attenuated cytotoxicity from glucose deprivation in PTG knockdown cells. Taken together, our findings identify a novel role for PTG in protecting hepatocellular carcinoma cells from metabolic stress, in part by regulating oxidative stress and autophagy.

Oxidative and nitrative stress in neurodegeneration.

Aerobes require oxygen for metabolism and normal free radical formation. As a result, maintaining the redox homeostasis is essential for brain cell survival due to their high metabolic energy requirement to sustain electrochemical gradients, neurotransmitter release, and membrane lipid stability. Further, brain antioxidant levels are limited compared to other organs and less able to compensate for reactive oxygen and nitrogen species (ROS/RNS) generation which contribute oxidative/nitrative stress (OS/NS). Antioxidant treatments such as vitamin E, minocycline, and resveratrol mediate neuroprotection by prolonging the incidence of or reversing OS and NS conditions. Redox imbalance occurs when the antioxidant capacity is overwhelmed, consequently leading to activation of alternate pathways that remain quiescent under normal conditions. If OS/NS fails to lead to adaptation, tissue damage and injury ensue, resulting in cell death and/or disease. The progression of OS/NS-mediated neurodegeneration along with contributions from microglial activation, dopamine metabolism, and diabetes comprise a detailed interconnected pathway. This review proposes a significant role for OS/NS and more specifically, lipid peroxidation (LPO) and other lipid modifications, by triggering microglial activation to elicit a neuroinflammatory state potentiated by diabetes or abnormal dopamine metabolism. Subsequently, sustained stress in the neuroinflammatory state overwhelms cellular defenses and prompts neurotoxicity resulting in the onset or amplification of brain damage.

NRMT1 knockout mice exhibit phenotypes associated with impaired DNA repair and premature aging.

Though defective genome maintenance and DNA repair have long been known to promote phenotypes of premature aging, the role protein methylation plays in these processes is only now emerging. We have recently identified the first N-terminal methyltransferase, NRMT1, which regulates protein-DNA interactions and is necessary for both accurate mitotic division and nucleotide excision repair. To demonstrate if complete loss of NRMT1 subsequently resulted in developmental or aging phenotypes, we constructed the first NRMT1 knockout (Nrmt1(-/-)) mouse. The majority of these mice die shortly after birth. However, the ones that survive, exhibit decreased body size, female-specific infertility, kyphosis, decreased mitochondrial function, and early-onset liver degeneration; phenotypes characteristic of other mouse models deficient in DNA repair. The livers from Nrmt1(-/-) mice produce less reactive oxygen species (ROS) than wild type controls, and Nrmt1(-/-) mouse embryonic fibroblasts show a decreased capacity for handling oxidative damage. This indicates that decreased mitochondrial function may benefit Nrmt1(-/-) mice and protect them from excess internal ROS and subsequent DNA damage. These studies position the NRMT1 knockout mouse as a useful new system for studying the effects of genomic instability and defective DNA damage repair on organismal and tissue-specific aging.

Recycling antibiotics into GUMBOS: a new combination strategy to combat multi-drug-resistant bacteria.

The emergence of multi-drug-resistant bacteria, coupled with the lack of new antibiotics in development, is fast evolving into a global crisis. New strategies utilizing existing antibacterial agents are urgently needed. We propose one such strategy in which four outmoded ß-lactam antibiotics (ampicillin, carbenicillin, cephalothin and oxacillin) and a well-known antiseptic (chlorhexidine di-acetate) were fashioned into a group of uniform materials based on organic salts (GUMBOS) as an alternative to conventional combination drug dosing strategies. The antibacterial activity of precursor ions (e.g., chlorhexidine diacetate and ß-lactam antibiotics), GUMBOS and their unreacted mixtures were studied with 25 clinical isolates with varying antibiotic resistance using a micro-broth dilution method. Acute cytotoxicity and therapeutic indices were determined using fibroblasts, endothelial and cervical cell lines. Intestinal permeability was predicted using a parallel artificial membrane permeability assay. GUMBOS formed from ineffective ß-lactam antibiotics and cytotoxic chlorhexidine diacetate exhibited unique pharmacological properties and profound antibacterial activity at lower concentrations than the unreacted mixture of precursor ions at equivalent stoichiometry. Reduced cytotoxicity to invasive cell types commonly found in superficial and chronic wounds was also observed using GUMBOS. GUMBOS show promise as an alternative combination drug strategy for treating wound infections caused by drug-resistant bacteria.

A structured approach to target starch solubilisation and hydrolysis for the sugarcane industry.

In sugarcane processing, starch is considered an impurity that negatively affects processing and reduces the quality of the sugar end-product. In the last decade, there has been a general world-wide increase in starch concentrations in sugarcane. Industrial α-amylases have been used for many years to mitigate issues arising from starch in the sugarcane industry. Mixed results have prompted further studies of the behaviour of different physical forms of starch and their interactions with α-amylases during processing. By using corn starch as a reference in model juices and syrups, processing parameters, activities, and hydrolysis of insoluble, swollen, and soluble starch forms were evaluated for two commercial α-amylases with high (HT) and intermediate (IT) temperature stability, respectively. The ability of starch to solubilise across a sugarcane factory is largely limited by increased Brix values. Optimum target locations and conditions for the application of α-amylases in sugarcane processing are discussed in detail.

Nitrite treatment rescues cardiac dysfunction in aged mice treated with conjugated linoleic acid.

Conjugated linoleic acid (cLA) is a commercially available weight-loss supplement that is not currently regulated by the U.S. FDA. Numerous studies suggest that cLA mediates protection against diseases including cancer, diabetes, atherosclerosis, immune function, and obesity. Based upon these reports, it was hypothesized that supplementation with cLA would improve heart function in aged wild-type (WT) mice. At 10 months of age, mice were treated with cLA, nitrite, or the combination of the two. Echocardiograms revealed that cardiac function was decreased in aged compared to young WT mice, as determined by percentage of fractional shortening. Also, contrary to the hypothesis, mice that received cLA (6-week treatment) had significantly worse cardiac function compared to controls. This effect was attenuated when mice were cotreated with cLA and nitrite. Taken together, these results suggest that cLA-mediated cardiac injury can be circumvented by nitrite supplementation in a murine model of aging.

Nuclear interaction between ADR-induced p65 and p53 mediates cardiac injury in iNOS (-/-) mice.

Adriamycin (ADR) treatment causes an imbalance in the levels of nitric oxide ((•)NO) and superoxide (O2(•-)) production leading to cardiac injury. Previously we demonstrated that mice lacking inducible nitric oxide synthase (iNOS) have increased oxidative stress and mitochondrial injury. The molecular events leading to increased mitochondrial injury in iNOS deficient mice is unknown. ADR in the absence of iNOS preferentially activates a proapoptotic pathway without a concurrent increase in prosurvival pathways. Treatment with ADR leads to an increase in DNA binding activity of nuclear factor kappa B (NFκB) and p53 in wildtype mice. Following ADR treatment, p53, but not NFκB DNA binding activity, as well as the level of Bax, a p53 target gene, was increased in iNOS (-/-) mice. This apoptotic signaling effect in iNOS (-/-) is alleviated by overexpression of manganese superoxide dismutase (MnSOD). Increases in NFκB and p53 in ADR-treated wildtype mice did not lead to increases in target genes such as MnSOD, bcl-xL, or Bax. Moreover, co-immunoprecipitation analysis revealed that p65, a prominent member of the NFκB family, interacts with p53 in the nucleus. These results suggest that NFκB and p53 may counter act one another's actions in ADR-treated wildtype (WT) mice. Further, these results identify a novel mechanism by which oxidative stress may regulate transcription of proapoptotic genes.

Co-treatment with conjugated linoleic acid and nitrite protects against myocardial infarction.

According to the CDC, the most common type of heart disease is coronary artery disease, which commonly leads to myocardial infarction (MI). Therapeutic approaches to lessen the resulting cardiovascular injury associated with MI are limited. Recently, MicroRNAs (miRNAs) have been shown to act as negative regulators of gene expression by inhibiting mRNA translation and/or stimulating mRNA degradation. A single miRNA can modulate physiological or disease phenotypes by regulating whole functional systems. Importantly, miRNAs can regulate cardiac function, thereby modulating heart muscle contraction, heart growth and morphogenesis. MicroRNA-499 (miRNA-499) is a cardiac-specific miRNA that when elevated causes cardiomyocyte hypertrophy, in turn preventing cardiac dysfunction during MI. Previous studies revealed that combination treatment with conjugated linoleic acid (cLA) and nitrite preserved cardiovascular function in mice. Therefore, it was hypothesized that cLA and nitrite may regulate miRNA-499, thus providing cardiac protection during MI. To test this hypothesis, 12-week old mice were treated with cLA (10 mg/kg/d-via osmotic mini-pump) or cLA and nitrite (50 ppm-drinking water) 3 days prior to MI (ligation of the left anterior descending artery). Echocardiography and pressure-volume (PV)-loop analysis revealed that cLA and nitrite-treated MI mice had improved heart function (10 days following MI) compared to untreated MI mice. Treatment with cLA and nitrite significantly induced levels of miRNA-499 compared to untreated MI mice. In addition, treatment with cLA and nitrite abolished MI-induced protein expression of p53 and dynamin-related protein-1 (DRP-1). Moreover, the antioxidant enzyme expression of heme oxygenase-1 (HO-1) was elevated in MI mice treated with cLA and nitrite compared to untreated MI mice. Confocal imaging on heart tissue confirmed expression the levels of HO-1 and p53. Taken together, these results suggest that therapeutic treatment with cLA and nitrite may provide significant protection during MI through regulation of both cardiac specific miRNA-499 and upregulation of phase 2 antioxidant enzyme expression.

Minimizing human infection from Escherichia coli O157:H7 using GUMBOS.

OBJECTIVES: Reduction in faecal shedding of Shiga toxin-producing enterohaemorrhagic Escherichia coli (EHEC) in food-producing animals is a viable strategy to minimize human disease initiated by exposure to these microorganisms. To this end, an intervention strategy involving the electrostatic hybridization of two commonly used anti-infective agents for veterinary practice (i.e. chlorhexidine and ampicillin) was evaluated to curtail EHEC-transmitted disease from ruminant sources. Chlorhexidine di-ampicillin is a novel group of uniform material based on organic salts (GUMBOS) with inherent in vitro antibacterial activity that comes from its parent antimicrobial ions, chlorhexidine and ampicillin. METHODS: Antibacterial activities for chlorhexidine diacetate, sodium ampicillin, chlorhexidine di-ampicillin and stoichiometrically equivalent 1 : 2 chlorhexidine diacetate : sodium ampicillin were assessed using the serial 2-fold dilution method and time-kill studies against seven isolates of E. coli O157:H7 and one non-pathogenic E. coli 25922. Further studies to investigate synergistic interactions of reacted and stoichiometrically equivalent unreacted antimicrobial agents at MICs and possible mechanisms were also investigated. RESULTS: Synergism and in vitro antibacterial activities against EHEC were observed in this study, which suggests chlorhexidine di-ampicillin could be a useful reagent in reducing EHEC transmission and minimizing EHEC-associated infections. Likewise, chlorhexidine di-ampicillin reduced HeLa cell toxicity as compared with chlorhexidine diacetate or the stoichiometric combination of antimicrobial agents. Further results suggest that the mechanisms of action of chlorhexidine di-ampicillin and chlorhexidine diacetate against E. coli O157:H7 are similar. CONCLUSIONS: Reacting antimicrobial GUMBOS as indicated in this study may enhance the approach to current combination drug therapeutic strategies for EHEC disease control and prevention.