Vitamin D and methicillin-resistant Staphylococcus aureus nasal carriage

3D printed scaffolds with quercetin and vitamin D3 nanocarriers: In vitro cellular evaluation

Increasing bone diseases and anomalies significantly challenge bone regeneration, necessitating the development of innovative implantable devices for effective healing. This study explores the potential of 3D-printed calcium phosphate (CaP) scaffolds functionalized with natural medicine to address this issue. Specifically, quercetin and vitamin D3 (QVD) encapsulated solid lipid nanoparticles (QVD-SLNs) are incorporated into the scaffold to enhance bone regeneration. The melt emulsification method is utilized to achieve high drug encapsulation efficiency (~98%) and controlled biphasic release kinetics. The process-structure-property performance of these systems allows more controlled release while maintaining healthy cell-material interactions. The functionalized scaffolds show ~1.3- and ~-1.6-fold increase in osteoblast cell proliferation and differentiation, respectively, as compared with the control. The treated scaffold demonstrates a reduction in osteoclastic activity as compared with the control. The QVD-SLN-loaded scaffolds show ~4.2-fold in vitro chemopreventive potential against osteosarcoma cells. Bacterial assessment with both Staphylococcus aureus and Pseudomonas aeruginosa shows a significant reduction in bacterial colony growth over the treated scaffold. These findings summarize that the release of QVD-SLNs through a 3D-printed CaP scaffold can treat various bone-related disorders for low or non-load-bearing applications.

Skin microbiome considerations for long haul space flights

Dysbiosis of the human skin microbiome has long been associated with changes to the pH of the skin, dermal immune function and chronic skin conditions. Dermatological issues have been noted as the most prevalent medical presentation in the microgravity environment of space. The change in gravitational forces has been implicated in human immuno-suppression, also impacted by changes in the gastrointestinal-skin axis and its impact on Vitamin D metabolism, altered microbial gene expression in resident flora (leading changes in biofilm formation) and increased virulence factors in potential pathogens. There are also other stressors to the skin microbiome unique to space travel, including increased exposure to radiation, prolonged periods of dry washing technique, air quality and changes in microbe replication and growth parameters. Optimal microbiome health leads to enhanced skin barrier manufacture and maintenance, along with improved skin immune function and healing. In a microgravity environment expected to be experienced during long space flights, disruptions to the skin microbiome, coupled with increased virulence of pathological viruses and bacteria has implications for holistic skin health, astronaut cognitive function and mental health, and is coupled with slowed rates of wound healing. Scenario management for holistic skin health and restoration of microbiome homeostasis on long space flights require consideration.

Risk Factors Associated with Vitamin D Status among Older Puerto Rican Adults

BACKGROUND

Vitamin D deficiency has been associated with health problems globally, but there is limited information on vitamin D status and associated risk factors among adults in underserved populations.

OBJECTIVE

This study aimed to identify risk factors for vitamin D deficiency/insufficiency among Puerto Rican adults from the Boston Puerto Rican Health Study (BPRHS).

METHODS

A total of 822 adults (45-75 y, at baseline) were included in these analyses. Deficiency was defined as serum 25-hydroxyvitamin D [25(OH)D] <30 and insufficiency as 30 to <50 nmol/L. Dietary intake was assessed with a validated FFQ. Associations between risk factors, including dietary vitamin D, supplement use, ancestry, skin pigmentation, months in the past year spent in a southern climate, and serum 25(OH)D were assessed with multivariable general linear models.

RESULTS

Approximately 13% of participants were deficient in 25(OH)D and another 43% insufficient. Skin pigment was associated with 25(OH)D using 3 measures, greater African ancestry (β ± SE) (-7.74 ± 2.91, P = 0.01); interviewer assessed dark or medium, compared with white, skin tone, (-5.09 ± 2.19, P = 0.02 and -5.89 ± 1.58, P < 0.001, respectively); and melanin index of the upper inner right arm, assessed using a spectrophotometer (-2.04 ± 0.84, P = 0.02). After adjusting for ancestry, factors associated with lower serum 25(OH)D included smoking (-4.49 ± 1.58, P = 0.01); BMI (-0.21 ± 0.10, P = 0.04); and spring compared with autumn blood draw (-4.66 ± 1.68, P = 0.004). Factors associated with higher serum 25(OH)D included female sex compared with male (4.03 ± 1.58, P = 0.01); dietary vitamin D intake μg/d (0.71 ± 0.25, P < 0.004); vitamin D supplement use (4.50 ± 1.87, P = 0.02); income to poverty ratio (0.01 ± 0.01, P = 0.06), and months in a southern climate during the past year (0.96 ± 0.56, P = 0.09).

CONCLUSIONS

Vitamin D deficiency/insufficiency was prevalent in this Puerto Rican population living in the northeastern USA. Several factors were associated with this, which may assist in identifying those at risk. Interventions are needed to improve serum 25(OH)D concentration, particularly among those with limited exposure to sunlight.

Immune-Based Anti-Staphylococcal Therapeutic Approaches

Widespread methicillin-resistant Staphylococcus aureus (S. aureus) infections within community and healthcare settings are responsible for accelerated development of antibiotic resistance. As the antibiotic pipeline began drying up, alternative strategies were sought for future treatment of S. aureus infections. Here, we review immune-based anti-staphylococcal strategies that, unlike conventional antibiotics, target non-essential gene products elaborated by the pathogen. These strategies stimulate narrow or broad host immune mechanisms that are critical for anti-staphylococcal defenses. Alternative approaches aim to disrupt bacterial virulence mechanisms that enhance pathogen survival or induce immunopathology. Although immune-based therapeutics are unlikely to replace antibiotics in patient treatment in the near term, they have the potential to significantly improve upon the performance of antibiotics for treatment of invasive staphylococcal diseases.

Circulating sex-steroids and Staphylococcus aureus nasal carriage in a general female population

OBJECTIVE

Staphylococcus aureus is a major human pathogen, and nasal carriers have an increased risk for infection and disease. The exploration of host determinants for nasal carriage is relevant to decrease infection burden. Former studies demonstrate lower carriage prevalence in women and among users of progestin-only contraceptives. The aim of this study was to investigate the possible associations between circulating sex-steroid hormones and nasal carriage of Staphylococcus aureus in a general population.

METHODS

In the population-based sixth Tromsø study (2007-2008) nurses collected nasal swab samples from 724 women aged 30-87 not using any exogenous hormones, and 700 of the women had a repeated nasal swab taken (median interval 28 days). We analysed a panel of serum sex-steroids by liquid chromatography tandem mass spectrometry, and collected information about lifestyle, health and anthropometric measures. Multivariable logistic regression was used to study the association between circulating sex-steroids and Staphylococcus aureus carriage (one swab) and persistent carriage (two swabs), while adjusting for potential confounding factors. Women in luteal phase were excluded in the analysis of androgens.

RESULTS

Staphylococcus aureus persistent nasal carriage prevalence was 22%. One standard deviation increase in testosterone and bioavailable testosterone was associated with lower odds of persistent nasal carriage, (OR = 0.57; 95% CI = 0.35-0.92 and OR = 0.52, 95% CI = 0.30-0.92) respectively. Analysis stratified by menopause gave similar findings. Persistent carriers had lower average levels of androstenedione and DHEA, however, not statistically significant.

CONCLUSION

This large population-based study supports that women with lower levels of circulating testosterone may have increased probability of Staphylococcus aureus persistent carriage.

Vitamin D Deficiency and Effects of Vitamin D Supplementation on Disease Severity in Patients with Atopic Dermatitis: A Systematic Review and Meta-Analysis in Adults and Children

Research has investigated 25-hydroxyvitamin D (25(OH)D) levels in the Atopic Dermatitis (AD) population, as well as changes in AD severity after vitamin D (VitD) supplementation. We performed an up-to-date systematic review and meta-analysis of these findings. Electronic searches of MEDLINE, EMBASE and COCHRANE up to February 2018 were performed. Observational studies comparing 25(OH)D between AD patients and controls, as well as trials documenting baseline serum 25(OH)D levels and clinical severity by either SCORAD/EASI scores, were included. Of the 1085 articles retrieved, sixteen were included. A meta-analysis of eleven studies of AD patients vs. healthy controls (HC) found a mean difference of −14 nmol/L (95% CI −25 to −2) for all studies and −16 nmol/L (95% CI −31 to −1) for the paediatric studies alone. A meta-analysis of three VitD supplementation trials found lower SCORAD by −11 points (95% CI −13 to −9, p < 0.00001). This surpasses the Minimal Clinical Important Difference for AD of 9.0 points (by 22%). There were greater improvements in trials lasting three months and the mean weighted dose of all trials was 1500–1600 IU/daily. Overall, the AD population, especially the paediatric subset, may be at high-risk for lower serum 25(OH)D. Supplementation with around 1600 IU/daily results in a clinically meaningful AD severity reduction.

Hormonal contraceptive use and Staphylococcus aureus nasal and throat carriage in a Norwegian youth population

BACKGROUND

Use of hormonal contraceptives has been associated with Staphylococcus aureus nasal carriage in adult women. However, the role of hormonal contraceptives in S. aureus colonization among adolescents and associations with progestin only contraceptives are unknown.

METHODS

We obtained nasal and throat swab samples from 439 girls aged 17-21 years in the population-based Tromsø study Fit Futures, 2012-2013, Norway, with information on lifestyle, health and biomarkers. We used multivariable logistic regression to study the association between use of hormonal contraceptives and Staphylococcus aureus carriage while adjusting for potential confounding factors.

RESULTS

Staphylococcus aureus nasal carriage prevalence were 34%, 42%, and 61% among progestin-only users, non-users, and progestin-estrogen combination contraceptive users, respectively (P<0.001). Use of combination contraceptives doubled the odds of nasal carriage (non-users reference; OR = 2.31, 95%CI = 1.43-3.74). The OR of nasal carriage was 0.29 among progestin-only users compared to combination contraceptives users (95% CI = 0.12-0.67).

DISCUSSION

In this study, use of combination hormonal contraceptives was associated with higher risk of Staphylococcus aureus nasal carriage in adolescent girls. Experimental design studies are needed to establish the role of exogenous sex steroids in Staphylococcus aureus colonization in women.

Serum vitamin D and diabetic foot complications

Background: Foot complications such as ulceration and neuropathy are common complications of diabetes mellitus (DM). Previous reports have demonstrated a possible increased risk of these complications in diabetic patients with low levels of serum vitamin D.Objectctive: The purpose of this study is to compare serum vitamin D levels in diabetic patients with and without Charcot neuroarthropathy (CN), peripheral arterial disease (PAD), infection (DFI), ulceration (DFU), and peripheral neuropathy (DPN). Design: A retrospective chart review of all patients undergoing foot and ankle surgery with a history of DM over a 13 month period was performed. From this cohort, fifty subjects with CN were matched with 50 without CN and preoperative lab values were compared. A secondary evaluation was performed on the subjects' other comorbidities including PAD, DFI, DFU, and DPN. Results: Seventy-eight percent of our patients had vitamin D deficiency or insufficiency. Preoperative serum vitamin D levels were not significantly different between diabetic patients with and without CN (p = 0.55). Diabetic patients with PAD (p = 0.03), DFI (p = 0.0006), and DFU (p = 0.04) were all found to have significantly lower serum vitamin D levels than diabetic patients without these complications. Lower levels of serum albumin and higher serum creatinine were also noted with subjects with PAD, DFI, DPN, and DFU. While seasonal serum vitamin D level fluctuation was noted, this difference did not reach statistical significance with the numbers available. Conclusion: We found various lower extremity complications to be associated with low serum vitamin D including PAD, DFI, and DFU. While other studies have questioned the role of vitamin D and CN, we were unable to identify any significant difference between diabetic patients with and without Charcot neuroarthropathy. Level of evidence: Level 2.

Vitamin D supplementation to persistent carriers of MRSA-a randomized and placebo-controlled clinical trial

Methicillin-resistant Staphylococcus aureus (MRSA) is resistant to all beta-lactam antibiotics and can cause severe infections that are difficult to treat. Eradication strategies with conventional antibiotics are not always effective and alternative approaches are warranted. Here, we tested the hypothesis that daily supplementation with vitamin D for 12 months would reduce MRSA carriage rates among a group of persistent carriers. This was a double-blind, placebo-controlled randomized trial with n = 65 persistent MRSA carriers with 25-hydroxy vitamin D₃ (25OHD) < 75 nmol/L, who were followed up with bacterial cultures at baseline and every 3 months for 1 year. The primary endpoint was the decline in MRSA positivity during the study period. The study was conducted in two MRSA outpatient clinics at the Karolinska University Hospital, Stockholm, Sweden. In total, n = 65 persistent MRSA carriers were randomized and n = 3 were lost to follow-up. Only patients deficient in vitamin D (< 75 nmol/L) were included. Vitamin D (4000 IU) or placebo/day was administered for 12 months. The decline in MRSA positivity was equal in the vitamin D and placebo group during the study period (OR, 1.00; 95% CI, 0.97–1.03; p = 0.928) and approximately 40% in both groups were MRSA-negative after 12 months. The vitamin D group produced 103 positive cultures out of 318 cultures (32.4%) from nose, throat, and perineum over the study period, whereas the placebo group produced 135/393 positive cultures (34.0%) (Fisher’s exact test, p = 0.94). Vitamin D supplementation did not influence MRSA carriage. Thus, available data does not support vitamin D supplementation to persistent MRSA carriers.

Trial registration:www.clinicaltrials.gov; NCT02178488.

Current insights into the role of human β-defensins in atopic dermatitis

Anti-microbial peptides or host defence peptides are small molecules that display both anti-microbial activities and complex immunomodulatory functions to protect against various diseases. Among these peptides, the human β-defensins (hBDs) are localized primarily in epithelial surfaces, including those of the skin, where they contribute to protective barriers. In atopic dermatitis skin lesions, altered skin barrier and immune dysregulation are believed to be responsible for reduced hBD synthesis. Impaired hBD expression in the skin is reportedly the leading cause of increased susceptibility to bacterial and viral infection in patients with atopic dermatitis. Although hBDs have considerable beneficial effects as anti-microbial agents and immunomodulators and may ameliorate atopic dermatitis clinically, recent evidence has also suggested the negative effects of hBDs in atopic dermatitis development. In the current review, we provide an overview of the regulation of hBDs and their role in the pathogenesis of atopic dermatitis. The efforts to utilize these molecules in clinical applications are also described.

Prevalence, risk factors and sequelae of Staphylococcus aureus carriage in diabetes: the Fremantle Diabetes Study Phase II

AIMS

To determine the prevalence and associates of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) carriage in community-based diabetes, and their relationship to hospitalization with S. aureus infection.

METHODS

A cross-sectional subset of 660 Fremantle Diabetes Study Phase II patients (mean±SD age 65.1±11.5years, 53.1% males) had nasal/axillary swabs as part of biennial review. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were measured in 358 patients. Those with positive swabs were invited back for a repeat swab. Hospitalizations with S. aureus infections were ascertained from validated data linkage. Multiple logistic regression was used to identify associates of carriage, and Cox proportional hazards modelling was used to determine predictors of subsequent hospitalization.

RESULTS

258 patients (39.1%) were positive for S. aureus and eight (3.1%) carried MRSA. S. aureus carriage was independently associated with being married/in a de facto relationship and inversely with older age and being born overseas (P≤0.043). Repeat swabs in 137 patients (53.1% of those with an initially positive swab) grew S. aureus in 113 (82.5%). Five of eight MRSA-positive patients were re-swabbed, and four were MRSA-positive. Independent predictors of hospitalization with staphylococcal infection after the initial swab were S. aureus carriage (hazard ratio (95% CI) 5.42 (1.49-19.79)), prior hospitalization with S. aureus (4.84 (1.19-19.63)) and Aboriginality (7.20 (1.91-27.17) (P≤0.027). Serum 25(OH)D was not associated with S. aureus carriage or subsequent hospitalization.

CONCLUSIONS

S. aureus and MRSA carriage in our patients was consistent with previous general population studies. There were no diabetes-specific risk factors. Persistent colonization may underlie the increased risk of hospitalization with S. aureus.

Vitamin D sufficiency and Staphylococcus aureus infection in children

Vitamin D promotes epithelial immunity by upregulating antimicrobial peptides, including LL-37, which have bactericidal activity against Staphylococcus aureus. We found that children with vitamin D deficiency or insufficiency [25-hydroxyvitamin D <30 ng/mL] were more likely to present with recurrent, rather than primary, S. aureus skin or soft tissue infection. Vitamin D sufficiency may be one of a myriad of host and environmental factors that can be directly impacted to reduce the frequency of S. aureus skin and soft tissue infection.

An update on the association of vitamin D deficiency with common infectious diseases

Vitamin D plays an important role in modulating the immune response to infections. Deficiency of vitamin D is a common condition, affecting both the general population and patients in health care facilities. Over the last decade, an increasing body of evidence has shown an association between vitamin D deficiency and an increased risk for acquiring several infectious diseases, as well as poorer outcomes in vitamin D deficient patients with infections. This review details recent developments in understanding the role of vitamin D in immunity, the antibacterial actions of vitamin D, the association between vitamin D deficiency and common infections (like sepsis, pneumonia, influenza, methicillin-resistant Staphylococcus aureus, human immunodeficiency virus type-1 (HIV), and hepatitis C virus (HCV)), potential therapeutic implications for vitamin D replacement, and future research directions.

Atopic dermatitis and vitamin D: facts and controversies

Patients with atopic dermatitis have genetically determined risk factors that affect the barrier function of the skin and immune responses that interact with environmental factors. Clinically, this results in an intensely pruriginous and inflamed skin that allows the penetration of irritants and allergens and predisposes patients to colonization and infection by microorganisms. Among the various etiological factors responsible for the increased prevalence of atopic diseases over the past few decades, the role of vitamin D has been emphasized. As the pathogenesis of AD involves a complex interplay of epidermal barrier dysfunction and dysregulated immune response, and vitamin D is involved in both processes, it is reasonable to expect that vitamin D's status could be associated with atopic dermatitis' risk or severity. Such association is suggested by epidemiological and experimental data. In this review, we will discuss the evidence for and against this controversial relationship, emphasizing the possible etiopathogenic mechanisms involved.

Is vitamin D deficiency associated with development of Acinetobacter baumannii infections in critically ill patients?

PURPOSE

A growing number of evidence demonstrates deficiency of vitamin D in critically ill patients. We aimed to evaluate the vitamin D status of our critically ill patients and its relevance to infections in these patients.

MATERIAL AND METHODS

We conducted a prospective observational study in 201 critically ill patients admitted to the medical intensive care unit of Gazi University Hospital between October 2009 through March 2011.

RESULTS

Sixty-nine percent of the patients were found to be vitamin D deficient. Infection rate was higher in the deficient group, though without statistical significance (P=.117). Infections with Acinetobacter baumannii was significantly more frequent in patients with Vitamin D deficiency (25% vs 10%, P=.012). The median level of 25-hydroxyvitamin D levels was 11.8 [6.3-17.2] ng/mL and 15.7 [8.1-28.9] ng/mL in patients with and without A baumannii infections respectively (P=.024). Logistic regression analysis demonstrated that vitamin D deficiency (P=.042) and invasive mechanical ventilation (P=.001) were the 2 independent risk factors in the development of A baumannii infections, in addition.

CONCLUSIONS

Vitamin D deficiency is common in critically ill patients. Even though there was no statistical difference between vitamin D deficient and sufficient patients regarding development of infections in general, A baumannii infections were significantly more frequent in the deficient group. Vitamin D deficiency was found as one of the independent risk factors for A baumannii infections. Further multicenter studies with a larger sample size are required to validate our data.

Staphylococcus aureus Colonization: Modulation of Host Immune Response and Impact on Human Vaccine Design

In apparent contrast to its invasive potential Staphylococcus aureus colonizes the anterior nares of 20–80% of the human population. The relationship between host and microbe appears particularly individualized and colonization status seems somehow predetermined. After decolonization, persistent carriers often become re-colonized with their prior S. aureus strain, whereas non-carriers resist experimental colonization. Efforts to identify factors facilitating colonization have thus far largely focused on the microorganism rather than on the human host. The host responds to S. aureus nasal colonization via local expression of anti-microbial peptides, lipids, and cytokines. Interplay with the co-existing microbiota also influences colonization and immune regulation. Transient or persistent S. aureus colonization induces specific systemic immune responses. Humoral responses are the most studied of these and little is known of cellular responses induced by colonization. Intriguingly, colonized patients who develop bacteremia may have a lower S. aureus-attributable mortality than their non-colonized counterparts. This could imply a staphylococcal-specific immune “priming” or immunomodulation occurring as a consequence of colonization and impacting on the outcome of infection. This has yet to be fully explored. An effective vaccine remains elusive. Anti-S. aureus vaccine strategies may need to drive both humoral and cellular immune responses to confer efficient protection. Understanding the influence of colonization on adaptive response is essential to intelligent vaccine design, and may determine the efficacy of vaccine-mediated immunity. Clinical trials should consider colonization status and the resulting impact of this on individual patient responses. We urgently need an increased appreciation of colonization and its modulation of host immunity.

Effect of vitamin D3 supplementation on Staphylococcus aureus nasal carriage: a randomized, double-blind, placebo-controlled trial in healthy adults

Observational studies have reported an inverse association between serum 25-hydroxyvitamin D (25OHD) concentrations and Staphylococcus aureus nasal carriage; however, clinical trials of vitamin D supplementation are lacking. To assess the effect of vitamin D3 supplementation on persistent S. aureus nasal carriage we conducted a randomized, double-blind, placebo-controlled trial among 322 healthy adults. Participants were given an oral dose of either 200 000 IU vitamin D3 for each of 2 months, followed by 100 000 IU monthly or placebo in an identical dosing regimen, for a total of 18 months. Nasal swabs for S. aureus culture and serum for 25OHD measurement were obtained at baseline, 6, 12 and 18 months of study. The mean baseline concentration of 25OHD was 72 nM (SD 22 nM). Vitamin D3 supplementation increased 25OHD levels which were maintained at >120 nM throughout the study. Nasal colonization by S. aureus was found in 31% of participants at baseline. Persistent carriage, defined as those that had positive S. aureus nasal cultures for all post-baseline swabs, occurred in 20% of the participants but vitamin D3 supplementation was not associated with a reduction in persistent carriage (OR = 1.39, 95% CI 0.63-3.06). Risk factor analysis showed that only gender was significantly associated with carriage, where women were less likely to be carriers than men (relative risk 0.83, 95% CI 0.54-0.99). Serum 25OHD concentrations were not associated with the risk of carriage. In conclusion, monthly administration of 100 000 IU of vitamin D3 did not reduce persistent S. aureus nasal carriage.

[Aspects of interest on vitamin D for the traumatologist and orthopaedic surgeon]

Vitamin D deficiency or insufficiency is a clinical problem particularly prevalent in elderly patients with low-energy fractures, particularly hip fractures, but has also been associated with stress fractures and high energy fractures. There is much evidence that supports the need to maintain adequate levels of vitamin D in the blood in order to; reduce the number of fragility fractures, furthering the consolidation of these, improve neuromuscular function of patients, prevent falls, prevent surgical infections, or improve the length of arthroplasties. However, it is rare for the orthopaedic surgeon to request the values of vitamin D in these patients and give the appropriate treatment It is recommended to maintain levels higher than 30-40ng/ml (75-100nmol/l) and increase vitamin D intake, in almost all cases, from 800 to 1,000IU/day to achieve these levels.

Could vitamin d have a potential anti-inflammatory and anti-infective role in bronchiectasis?

Bronchiectasis is a chronic infective and inflammatory respiratory disease that causes significant morbidity and mortality. Patients with non-cystic-fibrosis bronchiectasis are frequently vitamin D deficient, and vitamin D levels correlate with disease severity. Infection-specific actions of vitamin D include the enhancement of innate immunity and the moderation of inflammation caused by the adaptive immune response. Potentially, vitamin D could influence the processes that lead to bronchiectasis and the frequency and severity of acute exacerbations. Randomized trials of vitamin D supplementation have shown effects that are likely to be protective against the development of bronchiectasis. Several issues need to be clarified before the development of clinical trials to investigate the role of vitamin D in bronchiectasis. These include an optimal vitamin D supplementation dose and appropriate and sensitive outcome measures that include assessment of exacerbation frequency and severity, lung function, and health-related quality of life.

Vitamin D's potential to reduce the risk of hospital-acquired infections

Health care–associated and hospital-acquired infections are two entities associated with increased morbidity and mortality. They are highly costly and constitute a great burden to the health care system. Vitamin D deficiency (< 20 ng/ml) is prevalent and may be a key contributor to both acute and chronic ill health. Vitamin D deficiency is associated with decreased innate immunity and increased risk for infections. Vitamin D can positively influence a wide variety of microbial infections.

Herein we discuss hospital-acquired infections, such as pneumonia, bacteremias, urinary tract and surgical site infections, and the potential role vitamin D may play in ameliorating them. We also discuss how vitamin D might positively influence these infections and help contain health care costs. Pending further studies, we think it is prudent to check vitamin D status at hospital admission and to take immediate steps to address existing insufficient 25-hydroxyvitamin D levels.

Vitamin D and sepsis: An emerging relationship

Vitamin D insufficiency and sepsis are both highly prevalent worldwide problems and this article reviews the emerging science that is defining the intersections of these conditions. The importance of vitamin D’s role in skeletal health has long been understood but recent evidence is beginning to highlight its role in the functioning of other physiologic systems of the body. Basic science data reveal its integral role in local immune responses to pathogens and the systemic inflammatory pathways of sepsis. Furthermore, clinical scientists have found associations with respiratory infections, critical illness and sepsis but the causal relationship and its clinical impact have yet to be clearly defined. The article ends with speculations on the connections between racial disparities and seasonal differences in sepsis and vitamin D insufficiency.

Host- and microbe determinants that may influence the success of S. aureus colonization

Staphylococcus aureus may cause serious skin and soft tissue infections, deep abscesses, endocarditis, osteomyelitis, pneumonia, and sepsis. S. aureus persistently colonizes 25–30% of the adult human population, and S. aureus carriers have an increased risk for infections caused by the bacterium. The major site of colonization is the nose, i.e., the vestibulum nasi, which is covered with ordinary skin and hair follicles. Several host and microbe determinants are assumed to be associated with colonization. These include the presence and expression level of bacterial adhesins, which can adhere to various proteins in the extracellular matrix or on the cellular surface of human skin. The host expresses several antimicrobial peptides and lipids. The level of β-defensin 3, free sphingosine, and cis-6-hexadecenoic acid are found to be associated with nasal carriage of S. aureus. Other host factors are certain polymorphisms in Toll-like receptor 2, mannose-binding lectin, C-reactive protein, glucocorticoid-, and vitamin D receptor. Additional putative determinants for carriage include genetic variation and expression of microbial surface components recognizing adhesive matrix molecules and their interaction partners, as well as variation among humans in the ability of recognizing and responding appropriately to the bacteria. Moreover, the available microflora may influence the success of S. aureus colonization. In conclusion, colonization is a complex interplay between the bacteria and its host. Several bacterial and host factors are involved, and an increased molecular understanding of these are needed.

Antimicrobial implications of vitamin D

Evidence exists that vitamin D has a potential antimicrobial activity and its deficiency has deleterious effects on general well-being and longevity. Vitamin D may reduce the risk of infection through multiple mechanisms. Vitamin D boosts innate immunity by modulating production of anti-microbial peptides (AMPs) and cytokine response. Vitamin D and its analogues via these mechanisms are playing an increasing role in the management of atopic dermatitis, psoriasis, vitiligo, acne and rosacea. Vitamin D may reduce susceptibility to infection in patients with atopic dermatitis and the ability to regulate local immune and inflammatory responses offers exciting potential for understanding and treating chronic inflammatory dermatitides. Moreover, B and T cell activation as well as boosting the activity of monocytes and macrophages also contribute to a potent systemic anti-microbial effect. The direct invasion by pathogenic organisms may be minimized at sites such as the respiratory tract by enhancing clearance of invading organisms. A vitamin D replete state appears to benefit most infections, with the possible noteworthy exception of Leishmaniasis. Antibiotics remain an expensive option and misuse of these agents results in significant antibiotic resistance and contributes to escalating health care costs. Vitamin D constitutes an inexpensive prophylactic option and possibly therapeutic product either by itself or as a synergistic agent to traditional antimicrobial agents. This review outlines the specific antimicrobial properties of vitamin D in combating a wide range of organisms. We discuss the possible mechanisms by which vitamin D may have a therapeutic role in managing a variety of infections.

Staphylococcus aureus nasal carriage is associated with serum 25-hydroxyvitamin D levels, gender and smoking status. The Tromsø Staph and Skin Study

Vitamin D induces the expression of antimicrobial peptides with activity against Staphylococcus aureus. Thus, we studied the association between serum 25-hydroxyvitamin D (25(OH)D) and S. aureus nasal colonization and carriage. Nasal swabs, blood samples and clinical data from 2,115 women and 1,674 men, aged 30-87 years, were collected in the Tromsø Staph and Skin Study 2007-08, as part of the population-based sixth Tromsø Study. Multivariate logistic regression analyses were stratified by recognized risk factors for S. aureus carriage: sex, age and smoking. In non-smoking men, we observed a 6.6% and 6.7% decrease in the probability of S. aureus colonization and carriage, respectively, by each 5 nmol/l increase in serum 25(OH)D concentration (P < 0.001 and P = 0.001), and serum 25(OH)D > 59 nmol/l and ≥75 nmol/l as thresholds for ~30% and ~50% reduction in S. aureus colonization and carriage. In non-smoking men aged 44-60 years, the odds ratio for S. aureus colonization was 0.44 (95% confidence interval, 0.28-0.69) in the top tertile of serum 25(OH)D versus the bottom tertile. In women and smokers there were no such associations. Our study supports that serum vitamin D is a determinant of S. aureus colonization and carriage.

Atopic dermatitis: a disease of altered skin barrier and immune dysregulation

Atopic dermatitis (AD) is an important chronic or relapsing inflammatory skin disease that often precedes asthma and allergic disorders. New insights into the genetics and pathophysiology of AD point to an important role of structural abnormalities in the epidermis as well as immune dysregulation not only for this skin disease but also for the development of asthma and allergies. Patients with AD have a unique predisposition to colonization or infection by microbial organisms, most notably Staphylococcus aureus and herpes simplex virus. Measures directed at healing and protecting the skin barrier and addressing the immune dysregulation are essential in the treatment of patients with AD, and early intervention may improve outcomes for both the skin disease as well as other target organs.

Healthcare costs of methicillin resistant Staphylococcus aureus and Pseudomonas aeruginosa infections in veterans: role of vitamin D deficiency

Methicillin resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (P. aeruginosa) infections are frequently associated with hospitalization and increased healthcare costs. Vitamin D deficiency may contribute to increased costs for patients with these infections and there is evidence that vitamin D may have an antimicrobial role. To evaluate the role of vitamin D deficiency in the costs incurred with these infections, we studied the relationship of serum 25(OH)D levels to healthcare costs in veterans in the southeastern United States. Patients with both infections were vitamin D deficient to a similar extent and so were combined for further analysis. Vitamin D deficient patients had higher costs and service utilization than those who were not vitamin D deficient. Those with vitamin D deficiency had higher inpatient costs compared to the non-deficient group, and this difference was across most categories except for the number of inpatient hospitalizations or total number of days as an inpatient. Vitamin D deficiency was not significantly related to outpatient cost or service utilization parameters. We conclude that vitamin D deficiency is intimately linked to adverse healthcare costs in veterans with MRSA and P. aeruginosa infections. Vitamin D status should be assayed in patients with these infections.