Health Management with Reduced Antibiotic Use—The U.S. Experience

Since World War II the use of antimicrobial products associated with food animal production has increased. Antimicrobials along with evolving production practices have significantly increased throughput, animal welfare, and improved health. Concerns surrounding the growing significance of emerging and in some cases rapidly disseminating antibiotic (antimicrobial) resistant bacterial pathogens among human and livestock populations has stimulated a reassessment of this application. The negative publicity has led many consumers and activist groups to believe that protein derived from food animals grown in the absence of those drugs is safer than products derived from the conventionally reared. There is a general fear that antimicrobial usage in agriculture threatens the sustainability of human therapeutic agents and the public wellbeing. The issue has gradually emerged from “fringe group paranoia” to mainstream—finally impacting consumer choices.

Antimicrobial resistance concerns have stimulated a significant reaction by the US animal agriculture industry. Numerous pig production entities, large and small, have attempted to create additional pork product value by developing niche marketing opportunities. Thus far most of the subtherapeutic in-feed antimicrobial reduction has been voluntary in the US. Two production areas have developed where reduced usage occurs. First is the growth of antibiotic free production (ABF) and second is an increased use of treatment levels which avoids subtherapeutic criticism. The bulk of this article is directed at new production practices, pig health management, disease elimination, and biosecurity efforts that result from early industry attempts at reduced or excluded antimicrobial pig production. Raising antimicrobial (antibiotic) free (ABF) pork from birth is challenging for a variety of reasons. Some of these challenges can be cost effectively dealt with while others are difficult if not impossible to control in modern production environments. Healthy pig production is essential for sustainable ABF operations.     

Mycobacterium Ulcerans Treatment – Can Antibiotic Duration Be Reduced in Selected Patients?

Introduction

Mycobacterium ulcerans (M. ulcerans) is a necrotizing skin infection endemic to the Bellarine Peninsula, Australia. Current treatment recommendations include 8 weeks of combination antibiotics, with adjuvant surgery if necessary. However, antibiotic toxicity often results in early treatment cessation and local experience suggests that shorter antibiotic courses may be effective with concurrent surgery. We report the outcomes of patients in the Barwon Health M. ulcerans cohort who received shorter courses of antibiotic therapy than 8 weeks.

Methodology / Principal findings

A retrospective analysis was performed of all M. ulcerans infections treated at Barwon Health from March 1, 1998 to July 31, 2013. Sixty-two patients, with a median age of 65 years, received < 56 days of antibiotics and 51 (82%) of these patients underwent concurrent surgical excision. Most received a two-drug regimen of rifampicin combined with either ciprofloxacin or clarithromycin for a median 29 days (IQR 21–41days). Cessation rates were 55% for adverse events and 36% based on clinician decision. The overall success rate was 95% (98% with concurrent surgery; 82% with antibiotics alone) with a 50% success rate for those who received < 14 days of antibiotics increasing to 94% if they received 14–27 days and 100% for 28–55 days (p<0.01). A 100% success rate was seen for concurrent surgery and 14–27 days of antibiotics versus 67% for concurrent surgery and < 14 days of antibiotics (p = 0.12). No previously identified risk factors for treatment failure with surgery alone were associated with reduced treatment success rates with < 56 days of antibiotics.

Conclusion

In selected patients, antibiotic treatment durations for M. ulcerans shorter than the current WHO recommended 8 weeks duration may be associated with successful outcomes.     

Peptide Bond Formation via Nα-Protected Diacyldiselenides

International Journal of Peptide Research and Therapeutics - A simple, straightforward, for the peptide bond formation employing corresponding carboxylic acids and amines derived from amino acids...     

Reduced folate carrier-1 G80a gene polymorphism is associated with neuroblastoma’s development

Neuroblastoma is a malignant embryonal tumor of neural crest cells that give rise to the sympathetic nervous system, responsible for 10–70 % of all cases of childhood cancer. Because of its early appearance, it has been suggested that risk factors active in the prenatal can be associated with the pathogenesis of neuroblastoma. The aim of this study was to investigate whether the genetic polymorphisms MTHFR C677T and A1298C, MTR A2756G, TYMS 2R/3R and SLC19A1 G80A, involved in folate metabolism, increase the risk of neuroblastoma in Brazilian children. This study comprised 31 Brazilian children (0–14 years old) diagnosed with neuroblastoma compared with 92 controls. Investigation of polymorphisms MTHFR C677T, MTR A2756G and SLC19A1 A80G was performed using PCR–RFLP, the TYMS 2R/3R using PCR and MTHFR A1298C using AS-PCR. The SLC19A1 A80A genotype was significantly associated with the development of neuroblastoma, compared with the control group (Williams G-Test = 0.0286; OR = 5.1667; 95 % CI = 1.4481–18.4338; p = 0.0175). When analyzed together, the 80AG+AA genotypes showed a trend toward association (OR = 3.3033; 95 % CI = 1.0586–10.3080; p = 0.0563). Our results suggest that individuals carriers of genotype AA for the SLC19A1 gene present risk for the development of neuroblastoma and possibly have difficulty in absorption of folic acid by the cells, and this may adversely affect the metabolism of folate causing genomic instability and promoting the development of cancer. This is the first retrospective/prospective study to examine the relationship between polymorphisms of folate pathway genes and risk of neuroblastoma.     

Addicted? Reduced host resistance in populations with defensive symbionts

Heritable symbionts that protect their hosts from pathogens have been described in a wide range of insect species. By reducing the incidence or severity of infection, these symbionts have the potential to reduce the strength of selection on genes in the insect genome that increase resistance. Therefore, the presence of such symbionts may slow down the evolution of resistance. Here we investigated this idea by exposing Drosophila melanogaster populations to infection with the pathogenic Drosophila C virus (DCV) in the presence or absence of Wolbachia, a heritable symbiont of arthropods that confers protection against viruses. After nine generations of selection, we found that resistance to DCV had increased in all populations. However, in the presence of Wolbachia the resistant allele of pastrel—a gene that has a major effect on resistance to DCV—was at a lower frequency than in the symbiont-free populations. This finding suggests that defensive symbionts have the potential to hamper the evolution of insect resistance genes, potentially leading to a state of evolutionary addiction where the genetically susceptible insect host mostly relies on its symbiont to fight pathogens.     

Antimicrobial efficiency of some N,N′-bis(alkymethyl)-1,2-ethanediamine dioxides and N,N′-bis(alkylmethyl)-1,2-propanediamine dioxides

Ten dioxide species derived from N,N′-bis(alkylmethyl)-1,2-ethanediamine and N,N′-bis(alkylmethyl)-1,2-propanediamine were tested for their activity withStaphylococcus aureus, Escherichia coli andCandida albicans. A relation between the length of the alkylchain, and/or the molecule asymmetry, and the antimicrobial activity was found. Part V of the series Amine Oxides; part IV: Mlynarciket al.: Folia Microbiol. 24, 188 (1979).     

Human Trefoil Factor 2 Is a Lectin That Binds α-GlcNAc-capped Mucin Glycans with Antibiotic Activity against Helicobacter pylori

Helicobacter pylori infection is the major cause of gastric cancer and remains an important health care challenge. The trefoil factor peptides are a family of small highly conserved proteins that are claimed to play essential roles in cytoprotection and epithelial repair within the gastrointestinal tract. H. pylori colocalizes with MUC5AC at the gastric surface epithelium, but not with MUC6 secreted in concert with TFF2 by deep gastric glands. Both components of the gastric gland secretome associate non-covalently and show increased expression upon H. pylori infection. Although blood group active O-glycans of the Lewis-type form the basis of H. pylori adhesion to the surface mucin layer and to epithelial cells, α1,4-GlcNAc-capped O-glycans on gastric mucins were proposed to inhibit H. pylori growth as a natural antibiotic. We show here that the gastric glycoform of TFF2 is a calcium-independent lectin, which binds with high specificity to O-linked α1,4-GlcNAc-capped hexasaccharides on human and porcine stomach mucin. The structural assignments of two hexasaccharide isomers and the binding active glycotope were based on mass spectrometry, linkage analysis, ¹H nuclear magnetic resonance spectroscopy, glycan inhibition, and lectin competition of TFF2-mucin binding. Neoglycolipids derived from the C3/C6-linked branches of the two isomers revealed highly specific TFF2 binding to the 6-linked trisaccharide in GlcNAcα1-4Galβ1-4GlcNAcβ1-6(Fucα1-2Galβ1-3)GalNAc-ol(Structure 1). Supposedly, lectin TFF2 is involved in protection of gastric epithelia via a functional relationship to defense against H. pylori launched by antibiotic α1,4-GlcNAc-capped mucin glycans. Lectin-carbohydrate interaction may have also an impact on more general functional aspects of TFF members by mediating their binding to cell signaling receptors.     

Reduced protein oxidation in Wistar rats supplemented with marine ω3 PUFAs

The potential effects of various dietary eicosapentaenoic acid (EPA; 20:5) and docosahexaenoic acid (DHA; 22:6) ratios (1:1, 2:1, and 1:2, respectively) on protein redox states from plasma, kidney, skeletal muscle, and liver were investigated in Wistar rats. Dietary fish oil groups were compared with animals fed soybean and linseed oils, vegetable oils enriched in ω6 linoleic acid (LA; 18:2) and ω3 α-linolenic acid (ALA; 18:3), respectively. Fish oil treatments were effective at reducing the level of total fatty acids in plasma and enriching the plasmatic free fatty acid fraction and erythrocyte membranes in EPA and DHA. A proteomic approach consisting of fluorescein 5-thiosemicarbazide (FTSC) labeling of protein carbonyls, FTSC intensity visualization on 1-DE or 2-DE gels, and protein identification by MS/MS was used for the protein oxidation assessment. Albumin was found to be the most carbonylated protein in plasma for all dietary groups, and its oxidation level was significantly modulated by dietary interventions. Supplementation with an equal EPA:DHA ratio (1:1) showed the lowest oxidation score for plasma albumin, followed in increasing order of carbonylation by 1:2 <2:1 ≈ linseed < soybean. Oxidation patterns of myofibrillar skeletal muscle proteins and cytosolic proteins from kidney and liver also indicated a protective effect on proteins for the fish oil treatments, the 1:1 ratio exhibiting the lowest protein oxidation scores. The effect of fish oil treatments at reducing carbonylation on specific proteins from plasma (albumin), skeletal muscle (actin), and liver (albumin, argininosuccinate synthetase, 3-α-hydroxysteroid dehydrogenase) was remarkable. This investigation highlights the efficiency of dietary fish oil at reducing in vivo oxidative damage of proteins compared to oils enriched in the 18-carbon polyunsaturated fatty acids ω3 ALA and ω6 LA, and such antioxidant activity may differ among different fish oil sources because of variations in EPA/DHA content.     

Frequency of Antibiotic Resistance in a Swine Facility 2.5 Years After a Ban on Antibiotics

The addition of antibiotics to livestock feed has contributed to the selection of antibiotic-resistant bacteria in concentrated animal feeding operations and agricultural ecosystems. The objective of this study was to assess the occurrence of resistance to chlortetracycline and tylosin among bacterial populations at the Swine Complex of McGill University (Province of Quebec, Canada) in the absence of antibiotic administration to pigs for 2.5 years prior to the beginning of this study. Feces from ten pigs born from the same sow and provided feed without antibiotic were sampled during suckling (n = 6 for enumerations, n = 10 for PCR), weanling (n = 10 both for PCR and enumerations), growing (n = 10 both for PCR and enumerations), and finishing (n = 10 both for PCR and enumerations). The percentage of chlortetracycline-resistant anaerobic bacterial populations (Tet^R) was higher than that of tylosin-resistant anaerobic bacterial populations (Tyl^R) at weanling, growing, and finishing. Prior to the transportation of animals to the slaughterhouse, resistant populations varied between 6.5 and 9.4 Log colony-forming units g humid feces⁻¹. In all pigs, tet(L), tet(O), and erm(B) were detected at suckling and weanling, whereas only tet(O) was detected at growing and finishing. The abundance of tet(O) was similar between males and females at weanling and growing and reached 5.1 × 10⁵ and 5.6 × 10⁵ copies of tet(O)/ng of total DNA in males and females, respectively, at finishing. Results showed high abundances and proportions of Tet^R and Tyl^R anaerobic bacterial populations, as well as the occurrence of tet and erm resistance genes within these populations despite the absence of antibiotic administration to pigs at this swine production facility since January 2007, i.e., 2.5 years prior to the beginning of this study. This work showed that the occurrence of bacterial resistance to chlortetracycline and tylosin is high at the Swine Complex of McGill University.     

Allosteric Control of βII-Tryptase by a Redox Active Disulfide Bond

The S1A serine proteases function in many key biological processes such as development, immunity, and blood coagulation. S1A proteases contain a highly conserved disulfide bond (Cys¹⁹¹–Cys²²⁰ in chymotrypsin numbering) that links two β-loop structures that define the rim of the active site pocket. Mast cell βII-tryptase is a S1A protease that is associated with pathological inflammation. In this study, we have found that the conserved disulfide bond (Cys²²⁰–Cys²⁴⁸ in βII-tryptase) exists in oxidized and reduced states in the enzyme stored and secreted by mast cells. The disulfide bond has a standard redox potential of −301 mV and is stoichiometrically reduced by the inflammatory mediator, thioredoxin, with a rate constant of 350 m⁻¹ s⁻¹. The oxidized and reduced enzymes have different substrate specificity and catalytic efficiency for hydrolysis of both small and macromolecular substrates. These observations indicate that βII-tryptase activity is post-translationally regulated by an allosteric disulfide bond. It is likely that other S1A serine proteases are similarly regulated.     

Reduced Physiological Complexity in Robust Elderly Adults with the APOE ε4 Allele

Background

It is unclear whether the loss of physiological complexity during the aging process is due to genetic variations. The APOE gene has been studied extensively in regard to its relationship with aging-associated medical illness. We hypothesize that diminished physiological complexity, as measured by heart rate variability, is influenced by polymorphisms in the APOE allele among elderly individuals.

Methodology/Principal Findings

A total of 102 robust, non-demented, elderly subjects with normal functions of daily activities participated in this study (97 males and 5 females, aged 79.2±4.4 years, range 72–92 years). Among these individuals, the following two APOE genotypes were represented: ε4 non-carriers (n = 87, 85.3%) and ε4 carriers (n = 15, 14.7%). Multi-scale entropy (MSE), an analysis used in quantifying complexity for nonlinear time series, was employed to analyze heart-rate dynamics. Reduced physiological complexity, as measured by MSE, was significantly associated with the presence of the APOE ε4 allele in healthy elderly subjects, as compared to APOE ε4 allele non-carriers (24.6±5.5 versus 28.9±5.2, F = 9.429, p = 0.003, respectively).

Conclusions/Significance

This finding suggests a role for the APOE gene in the diminished physiological complexity seen in elderly populations.     

Thiobenzothiazole-modified Hydrocortisones Display Anti-inflammatory Activity with Reduced Impact on Islet β-Cell Function

Glucocorticoids signal through the glucocorticoid receptor (GR) and are administered clinically for a variety of situations, including inflammatory disorders, specific cancers, rheumatoid arthritis, and organ/tissue transplantation. However, glucocorticoid therapy is also associated with additional complications, including steroid-induced diabetes. We hypothesized that modification of the steroid backbone is one strategy to enhance the therapeutic potential of GR activation. Toward this goal, two commercially unavailable, thiobenzothiazole-containing derivatives of hydrocortisone (termed MS4 and MS6) were examined using 832/13 rat insulinoma cells as well as rodent and human islets. We found that MS4 had transrepression properties but lacked transactivation ability, whereas MS6 retained both transactivation and transrepression activities. In addition, MS4 and MS6 both displayed anti-inflammatory activity. Furthermore, MS4 displayed reduced impact on islet β-cell function in both rodent and human islets. Similar to dexamethasone, MS6 promoted adipocyte development in vitro, whereas MS4 did not. Moreover, neither MS4 nor MS6 activated the Pck1 (Pepck) gene in primary rat hepatocytes. We conclude that modification of the functional groups attached to the D-ring of the hydrocortisone steroid molecule produces compounds with altered structure-function GR agonist activity with decreased impact on insulin secretion and reduced adipogenic potential but with preservation of anti-inflammatory activity.