Potential of lactoferrin to prevent antibiotic-induced Clostridium difficile infection

Objectives: C. difficile infection (CDI) is a global healthcare problem. Recent evidence suggests that the availability of iron may be important for C. difficile growth. This study evaluated the comparative effects of iron-depleted (1% Fe3+ saturated) bovine apo-lactoferrin (apo-bLf) and iron-saturated (85% Fe3+ saturated) bovine holo-lactoferrin (holo-bLf) in a human in vitro gut model that simulates CDI. Methods: Two parallel triple-stage chemostat gut models were inoculated with pooled human faeces and spiked with C. difficile spores (strain 027 210, PCR ribotype 027). Holo- or apo-bLf was instilled (5mg/mL, once daily) for 35 days. After 7 days, clindamycin was instilled (33.9mg/L, four times daily) to induce simulated CDI. Indigenous microflora populations, C. difficile total counts and spores , cytotoxin titres, short-chain fatty acids, biometals, lactoferrin, and iron content of lactoferrin were monitored daily. Results: In the apo-bLf model, germination of C. difficile spores occurred 6 days post-clindamycin, followed by rapid vegetative cell proliferation and detectable toxin. By contrast, in the holo-bLf model, only a modest vegetative cell population was observed until 16 days post-antibiotic. Notably, no toxin was detected in this model. In separate batch culture experiments, holo-bLf prevented C. difficile vegetative cell growth and toxin production, whereas apo-bLf and iron alone did not. Conclusions: Holo-bLf but not apo-bLf delayed C. difficile growth and prevented toxin production in a human gut model of CDI. This inhibitory effect may be iron-independent. These observations suggest that bLf in its iron-saturated state could be used as a novel preventative or treatment strategy for CDI

Glucose Availability and AMP-Activated Protein Kinase Link Energy Metabolism and Innate Immunity in the Bovine Endometrium

Defences against the bacteria that usually infect the endometrium of postpartum cattle are impaired when there is metabolic energy stress, leading to endometritis and infertility. The endometrial response to bacteria depends on innate immunity, with recognition of pathogen-associated molecular patterns stimulating inflammation, characterised by secretion of interleukin (IL)-1β, IL-6 and IL-8. How metabolic stress impacts tissue responses to pathogens is unclear, but integration of energy metabolism and innate immunity means that stressing one system might affect the other. Here we tested the hypothesis that homeostatic pathways integrate energy metabolism and innate immunity in bovine endometrial tissue. Glucose deprivation reduced the secretion of IL-1β, IL-6 and IL-8 from ex vivo organ cultures of bovine endometrium challenged with the pathogen-associated molecular patterns lipopolysaccharide and bacterial lipopeptide. Endometrial inflammatory responses to lipopolysaccharide were also reduced by small molecules that activate or inhibit the intracellular sensor of energy, AMP-activated protein kinase (AMPK). However, inhibition of mammalian target of rapamycin, which is a more global metabolic sensor than AMPK, had little effect on inflammation. Similarly, endometrial inflammatory responses to lipopolysaccharide were not affected by insulin-like growth factor-1, which is an endocrine regulator of metabolism. Interestingly, the inflammatory responses to lipopolysaccharide increased endometrial glucose consumption and induced the Warburg effect, which could exacerbate deficits in glucose availability in the tissue. In conclusion, metabolic energy stress perturbed inflammatory responses to pathogen-associated molecular patterns in bovine endometrial tissue, and the most fundamental regulators of cellular energy, glucose availability and AMPK, had the greatest impact on innate immunity

Surviving in isolation: genetic variation, bottlenecks and reproductive strategies in the Canarian endemic Limonium macrophyllum (Plumbaginaceae)

Oceanic archipelagos are typically rich in endemic taxa, because they offer ideal conditions for diversification and speciation in isolation. One of the most remarkable evolutionary radiations on the Canary Islands comprises the 16 species included in Limonium subsection Nobiles, all of which are subject to diverse threats, and legally protected. Since many of them are single-island endemics limited to one or a few populations, there exists a risk that a loss of genetic variation might limit their longterm survival. In this study, we used eight newly developed microsatellite markers to characterize the levels of genetic variation and inbreeding in L. macrophyllum, a species endemic to the North-east of Tenerife that belongs to Limonium subsection Nobiles. We detected generally low levels of genetic variation over all populations (HT = 0.363), and substantial differentiation among populations (FST = 0.188;RST = 0.186) coupled with a negligible degree of inbreeding (F = 0.042). Obligate outcrossing may have maintained L. macrophyllum relatively unaffected by inbreeding despite the species’ limited dispersal ability and the genetic bottlenecks likely caused by a prolonged history of grazing. Although several factors still constitute a risk for the conservation of L. macrophyllum, the lack of inbreeding and the recent positive demographic trends observed in the populations of this species are factors that favour its future persistence

Single Cigarette Sales: State Differences in FDA Advertising and Labeling Violations, 2014, United States

IMPORTANCE: Single cigarettes, which are sold without warning labels and often evade taxes, can serve as a gateway for youth smoking. The Family Smoking Prevention and Tobacco Control Act of 2009 gives the US Food and Drug Administration (FDA) authority to regulate the manufacture, distribution, and marketing of tobacco products, including prohibiting the sale of single cigarettes. To enforce these regulations, the FDA conducted over 335 661 inspections between 2010 and September 30, 2014, and allocated over $115 million toward state inspections contracts. OBJECTIVE: To examine differences in single cigarette violations across states and determine if likely correlates of single cigarette sales predict single cigarette violations at the state level. DESIGN: Cross-sectional study of publicly available FDA warning letters from January 1 to July 31, 2014. SETTING: All 50 states and the District of Columbia. PARTICIPANTS: Tobacco retailer inspections conducted by FDA (n = 33 543). EXPOSURE(S) FOR OBSERVATIONAL STUDIES: State cigarette tax, youth smoking prevalence, poverty, and tobacco production. MAIN OUTCOME(S) AND MEASURE(S): State proportion of FDA warning letters issued for single cigarette violations. RESULTS: There are striking differences in the number of single cigarette violations found by state, with 38 states producing no warning letters for selling single cigarettes even as state policymakers developed legislation to address retailer sales of single cigarettes. The state proportion of warning letters issued for single cigarettes is not predicted by state cigarette tax, youth smoking, poverty, or tobacco production, P = .12. CONCLUSIONS AND RELEVANCE: Substantial, unexplained variation exists in violations of single cigarette sales among states. These data suggest the possibility of differences in implementation of FDA inspections and the need for stronger quality monitoring processes across states implementing FDA inspections