The cutaneous microbiome in hospitalized patients with pressure ulcers

Pressure injuries and biofilms: Microbiome, model systems and therapies

Chronic wounds have emerged as significant clinical problems owing to their increasing incidence and greater recognition of associated morbidity and socio-economic burden. They are defined as wounds that do not progress normally through the stages of healing in a timely and/or orderly manner. Pressure injuries, in particular, represent a serious problem for patients who are elderly or have limited mobility, such as wheelchair users or those who spend most of the day in bed. These injuries often result from prolonged pressure exerted on the skin over the bone. Treatment of pressure injuries is complex and costly. Emerging evidence suggests that the pressure injury microbiome plays a vital role in chronic wound formation and delaying wound healing. Additionally, antibiotics often fail due to the formation of resistant biofilms and the emergence of antimicrobial-resistant bacteria. In this review, we will summarise the current knowledge on: (a) biofilms and microbiomes in pressure injuries; (b) in vitro and in vivo model systems to study pressure injuries, and (c) current therapies and novel treatment approaches. Understanding the complex interactions between microbes and the host immune system in pressure injuries will provide valuable insights to improve patient outcomes.

Modulations of the skin microbiome in skin disorders: A narrative review from a wound care perspective

The cutaneous microbiome represents a highly dynamic community of bacteria, fungi and viruses. Scientific evidence, particularly from the last two decades, has revealed that these organisms are far from being inconsequential microscopic hitchhikers on the human body, nor are they all opportunistic pathogens waiting for the chance to penetrate the skin barrier and cause infection. In this review, we will describe how dermatological diseases have been found to be associated with disruptions and imbalances in the skin microbiome and how this new evidence had shaped the diagnosis and clinical practice relating to these disorders. We will identify the microbial agents which have been found to directly exacerbate skin diseases, as well as those which can ameliorate many of the symptoms associated with dermatological disorders. Furthermore, we will discuss the studies which suggest that bacteriotherapy, either by topical use of probiotics or by bacteria-derived compounds, can rectify skin microbial imbalances, thereby offering a promising alternative to antibiotic treatment and reducing the risks of antibiotic resistance.

Skin dysbiosis and loss of microbiome site specificity in critically ill patients

An increasing amount of evidence has linked critical illness with dysbiotic microbiome signatures in different body sites. The disturbance of the indigenous microbiota structures has been further associated with disease severity and outcome and has been suggested to pose an additional risk for complications in intensive care units (ICUs), including hospital-acquired infections. A better understanding of the microbial dysbiosis in critical illness might thus help to develop strategies for the prevention of such complications. While most of the studies addressing microbiome changes in ICU patients have focused on the gut, the lung, or the oral cavity, little is known about the microbial communities on the skin of ICU patients. Since the skin is the outermost organ and the first immune barrier against pathogens, its microbiome might play an important role in the risk management for critically ill patients. This observational study characterizes the skin microbiome in ICU patients covering five different body sites at the time of admission. Our results show a profound dysbiosis on the skin of critically ill patients, which is characterized by a loss of site specificity and an overrepresentation of gut bacteria on all skin sites when compared to a healthy group. This study opens a new avenue for further investigations on the effect of skin dysbiosis in the ICU setting and points out the need of strategies for the management of dysbiosis in critically ill patients.IMPORTANCEUnbalanced gut microbiota in critically ill patients has been associated with poor outcome and complications during the intensive care unit (ICU) stay. Whether the disturbance of the microbial communities in these patients is extensive for other body sites, such as the skin, is largely unknown. The skin not only is the largest organ of the body but also serves as the first immune barrier against potential pathogens. This study characterized the skin microbiota on five different body sites in ICU patients at the time of admission. The observed disturbance of the bacterial communities might help to develop new strategies in the risk management of critically ill patients.

Evaluation of the antimicrobial effect of the Origanum vulgare L essential oil on strains of Klebsiella pneumoniae

Bacteria may be the initial cause of certain pathologies as well as a secondary agent responsible for the development of complications such as pressure ulcer infections. Pressure ulcers are a persistent health problem, especially in immunocompromised patients, and associated with infection by opportunistic microorganisms with antimicrobial resistance, such as Klebsiella pneumoniae, highlight the need for the development of new antimicrobial approaches. Thus, the aim of this study was to evaluate the antibacterial and anti-adherent activity of Origanum vulgare L. (oregano) essential oil against Klebsiella pneumoniae strains, as well as the effect of its association with synthetic antimicrobials. To this end, the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) analyses were performed on microdilution plates. The assay of the Minimum Inhibitory Adherence Concentration (MIAC), with test tubes. As well as, the association study through the infusion disc method containing ampicillin (AMP), gentamicin (GEN), ciprofloxacin (CIP) and ceftriaxone (CEF). Therefore, it was possible to obtain that the essential oil of oregano presents antimicrobial and bactericidal activity, with MIC ranging between 128μg/mL and 256 μg/mL and MBC between 256 μg/mL and 512 μg/mL, on the tested K. pneumoniae strains. When used in association with ampicillin and gentamicin, oregano essential oil showed synergistic effect for some strains. Therefore, it is observed that the tested essential oil can act as a promising antibacterial in the treatment of diseases caused by K. pneumoniae.

Sodium Danshensu Cream Promotes the Healing of Pressure Ulcers in Mice through the Nrf2/HO-1 and NF-κB Pathways

On the basis of the mice pressure ulcers (PU) model, the protective effect and potential mechanism of sodium Danshensu (SDSS) cream against PU were investigated. The mice were randomly divided into three groups: the negative control group (cream without 0.5 g SDSS), the SDSS group (cream containing 0.5 g SDSS), and the positive group (0.5 g Hirudoid®). After 7 and 14 days of ointment application, the wound-healing rate of the SDSS and positive groups was significantly higher than that of the control group (p < 0.05). The results of hematoxylin−eosin staining also indicated that SDSS has the potential to promote the healing of PU. In addition, the serum IL-6, IL-1β, TNF-α, and MDA levels decreased significantly (p < 0.01) after 14 days of SDSS treatment, while the SOD, CAT, and GSH-Px activities increased significantly (p < 0.01). In addition, SDSS cream was able to significantly increase the expression of Nrf2, HO-1, GCLM, NQO1, NF-κB p65, NF-κB p50, IKKα, and IKKβ while decreasing the expression of Keap1 and IκBαin the Nrf2/HO-1 and NF-κB pathways. Our research will provide a foundation for the future clinical prevention and treatment of PU with SDSS cream.

Towards standardized and reproducible research in skin microbiomes

Skin is a complex organ serving a critical role as a barrier and mediator of interactions between the human body and its environment. Recent studies have uncovered how resident microbial communities play a significant role in maintaining the normal healthy function of the skin and the immune system. In turn, numerous host-associated and environmental factors influence these communities' composition and diversity across the cutaneous surface. In addition, specific compositional changes in skin microbiota have also been connected to the development of several chronic diseases. The current era of microbiome research is characterized by its reliance on large data sets of nucleotide sequences produced with high-throughput sequencing of sample-extracted DNA. These approaches have yielded new insights into many previously uncharacterized microbial communities. Application of standardized practices in the study of skin microbial communities could help us understand their complex structures, functional capacities, and health associations and increase the reproducibility of the research. Here, we overview the current research in human skin microbiomes and outline challenges specific to their study. Furthermore, we provide perspectives on recent advances in methods, analytical tools and applications of skin microbiomes in medicine and forensics.

Recent technological advances in the management of chronic wounds: A literature review

Background

Wound treatment comprises a substantial portion of the healthcare budgets in developed countries. Studies suggest that about 50% of patients admitted to hospitals have wounds, while 1%−2% of the general population in the developed world suffers from chronic wounds. Chronic wounds fail to repair themselves within the expected period of 30 days. Technologies have been developed to address challenges encountered during wound care with the aim of alleviating pain, promoting healing, or controlling wound infections.

Objective

The objective of this study was to explore the technological improvements that have been made in this field over time.

Methods

To gain insight into the future of wound management, a systematic review of literature on the subject was conducted in scientific databases (PubMed, Scopus, Web of Science, Medline, and Clinical Trials).

Results and Discussion

Results indicate that wound dressings have evolved from the traditional cotton gauze to composite materials embedded with appropriate ingredients such as metal‐based nanoparticles. Studies on biodegradable dressing materials are also underway to explore their applicability in dressing large and irregular wounds. On the other hand, conventional drugs and traditional formulations for the management of pain, inflammation, infections, and accelerating healing have been developed. However, more research needs to be carried out to address the issue of microbial resistance to drugs. Drugs for managing other ailments also need to be designed in such a way that they can augment wound healing. In addition, it has been demonstrated that a coordinated integration of conventional and traditional medicine can produce laudable results in chronic wound management.

Conclusion

Accordingly, collaborative efforts and ingenuity of all players in the field can accelerate technological advances in the wound care market to the benefit of the patients.

Wounds affect about 50% of patients admitted to hospitals.

Technologies have been developed including biodegradable dressing materials to address underlying challenges.

Technological advancement, rising incidences of chronic wounds, growing government support, and a rising elderly population will drive wound market growth.

A careful combination of recent research outputs can greatly change wound care technologies.

This review highlights the recent research advances and opportunities in the wound care field.

The future lies in biodegradable dressing materials, probably embedded with selected nanoparticles and which shall be combined in predetermined ratios.

Skin Microbiota Was Altered in Crocodile Lizards (Shinisaurus crocodilurus) With Skin Ulcer

Skin diseases commonly affect reptiles, but their relationships to the closely related skin microbiome are not well-understood. In recent years, both the wild and captive populations of the crocodile lizard, a Class I protected endangered animal in China, have suffered serious skin diseases that hamper the rescue and release projects for their conservation. This study conducted a detailed prevalence investigation of a major dermatosis characterized by foot skin ulcer in crocodile lizards. It should be noticed that skin ulcer has been prevalent in both captive and wild populations. There was positive correlation between skin ulcer and temperature, while no significant relationship between skin ulcer and humidity, sex, and age. We further studied the relationship between skin ulcer and the skin microbiota using meta-taxonomics. Results showed that the skin microbiota of crocodile lizards was significantly different from those of the environmental microbial communities, and that skin microbiota had a significant relationship with skin ulcer despite the impact of environment. Both bacterial and fungal communities on the ulcerated skin were significantly changed, which was characterized by lower community diversity and different dominant microbes. Our findings provide an insight into the relationship between skin microbiota and skin disease in reptile, serving as a reference for dermatological etiology in wildlife conservation.

Gut microbiota and short-chain fatty acid alterations in cachectic cancer patients

BACKGROUND

Cancer cachexia is characterized by a negative energy balance, muscle and adipose tissue wasting, insulin resistance, and systemic inflammation. Because of its strong negative impact on prognosis and its multifactorial nature that is still not fully understood, cachexia remains an important challenge in the field of cancer treatment. Recent animal studies indicate that the gut microbiota is involved in the pathogenesis and manifestation of cancer cachexia, but human data are lacking. The present study investigates gut microbiota composition, short-chain fatty acids (SCFA), and inflammatory parameters in human cancer cachexia.

METHODS

Faecal samples were prospectively collected in patients (N = 107) with pancreatic cancer, lung cancer, breast cancer, or ovarian cancer. Household partners (N = 76) of the patients were included as healthy controls with similar diet and environmental conditions. Patients were classified as cachectic if they lost >5% body weight in the last 6 months. Gut microbiota composition was analysed by sequencing of the 16S rRNA V4 gene region. Faecal SCFA levels were quantified by gas chromatography. Faecal calprotectin was assessed with enzyme-linked immunosorbent assay. Serum C-reactive protein and leucocyte counts were retrieved from medical records.

RESULTS

Cachexia prevalence was highest in pancreatic cancer (66.7%), followed by ovarian cancer (25%), lung cancer (20.8%), and breast cancer (17.3%). Microbial α-diversity was not significantly different between cachectic cancer patients (N = 33), non-cachectic cancer patients (N = 74), or healthy controls (N = 76) (species richness P = 0.31; Shannon effective index P = 0.46). Community structure (β-diversity) tended to differ between these groups (P = 0.053), although overall differences were subtle and no clear clustering of samples was observed. Proteobacteria (P < 0.001), an unknown genus from the Enterobacteriaceae family (P < 0.01), and Veillonella (P < 0.001) were more abundant among cachectic cancer patients. Megamonas (P < 0.05) and Peptococcus (P < 0.001) also showed differential abundance. Faecal levels of all SCFA tended to be lower in cachectic cancer patients, but only acetate concentrations were significantly reduced (P < 0.05). Faecal calprotectin levels were positively correlated with the abundance of Peptococcus, unknown Enterobacteriaceae, and Veillonella. We also identified several correlations and interactions between clinical and microbial parameters.

CONCLUSIONS

This clinical study provided the first insights into the alterations of gut microbiota composition and SCFA levels that occur in cachectic cancer patients and how they are related to inflammatory parameters. These results pave the way for further research examining the role of the gut microbiota in cancer cachexia and its potential use as therapeutic target.

LimpiAD foam and the potential control of the pressure ulcers onset

Pressure ulcers development is an undesirable event that often worsens the clinical condition of patients already affected by severe pathologies. Since the aetiology of this clinical complication is unclear yet, at current the primary approach to treat the problem is the adoption of suitable patients' assistance procedures. At the same time, the research focuses on finding medicaments or treatment strategies that could prevent the lesions and/or accelerate their healing. The international market's wide range of cosmetic/pharmaceuticals products is mainly topical preparations based on emollient agents to preserve or restore skin homeostasis. On the other hand, the skin microbiome's implication in the pressure ulcers occurrence is mainly unknown. Based on these assumptions, here we tested an innovative preparation, the LimpiAD foam, as a potential preventive strategy of pressure ulcers onset. The active component of this product is composed of hyaluronic acid conjugated with a bacterial cell wall fragment of C. acnes DSM 28251. For LimpiAD foam, we hypothesised a combined action of the two components on the skin tissue, an emollient effect due to the hyaluronic acid properties together with a modulatory effect on the skin microbiota carried out by the component of bacterial derivation. Our results supported the hypothesis and suggested a potential role of LimpiAD foam in pressure ulcers prevention.

Immunomodulatory and anti-infective effects of Cratylia mollis lectin (Cramoll) in a model of wound infection induced by Staphylococcus aureus

This work evaluated the immunomodulatory and anti-infective effects of Cratylia mollis lectin (Cramoll) in a model of wound infection induced by S. aureus. Swiss mice were divided into 3 groups (n = 12/group): non-inoculated (Control group); inoculated with S. aureus (Sa group); inoculated with S. aureus and treated with Cramoll (Sa + Cramoll group). In each animal, one lesion (64 mm²) was induced on the back and contaminated with S. aureus (~4.0 × 10⁶ CFU/wound). The treatment with Cramoll (5 μg/animal/day) started 1-day post-infection (dpi) and extended for 10 days. Clinical parameters (wound size, inflammatory aspects, etc.) were daily recorded; while cytokines levels, bacterial load and histological aspects were determined in the cutaneous tissue at 4^th dpi or 11^th dpi. The mice infected with S. aureus exhibited a delay in wound contraction and the highest inflammatory scores. These effects were impaired by the treatment with Cramoll which reduced the release of key inflammatory mediators (TNF-α, NO, VEGF) and the bacterial load at wound tissue. Histological evaluations showed a restauration of skin structures in the animals treated with Cramoll. Taken together, these results provide more insights about the healing and immunomodulatory properties of Cramoll and suggest this lectin as a lead compound for treatment of wound infection.

Association of Skin Microbiome with the Onset and Recurrence of Pressure Injury in Bedridden Elderly People

Pressure injuries have been identified as one of the main health hazards among bedridden elderly people. Bedridden elderly people often stay in the same position for a long time, because they cannot switch positions; thus, the blood flow in the part of the body that is being compressed between the bed and their own weight is continuously blocked. As a result, redness and ulcers occur due to lacking oxygen and nutrients in the skin tissues, and these sites are often infected with microorganisms and, thus, become suppurative wounds, a condition commonly determined as pressure injuries. If left untreated, the pressure injury will recur with microbial infections, often resulting in cellulitis, osteomyelitis, and sepsis. The skin microbiome, in which many types of bacteria coexist, is formed on the skin surface. However, it remains unclear what characteristic of the skin microbiome among the bedridden elderly constitutes the development and severity of pressure injuries and the development of post-pressure injury infections. Thus, in this review article, we outlined the changes in the skin microbiome among the bedridden elderly people and their potential involvement in the onset and recurrence of pressure injuries.

Does the presence of bacterial urinary infection contribute to the development of incontinence-associated dermatitis? A scoping review

OBJECTIVE

Incontinence-associated dermatitis (IAD) is an inflammatory skin condition caused by the repeated exposure to urine and faeces. It is not common for urinary incontinence only to cause IAD, however patients with urinary tract infections (UTIs) are also at increased risk for IAD. This scoping review aimed to provide a summary of the relationship between bacterial urinary infections and IAD.

METHODS

We conducted a scoping review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. PubMed, CINAHL, Medline, and Web of Science were searched for relevant articles from January 2007 through February 2020.

RESULTS

Based on eligibility criteria, 13 research studies and review articles were included. Despite the acknowledged role of bacterial infections can play in IAD and the importance of eradicating infections for the prevention of skin breakdown, there have been limited studies that have investigated how uropathogenic bacteria, in combination with urine, lead to skin damage and IAD. The use of urinary catheters also predisposes to UTIs; however, prevalence/incidence rates of IAD in these patients are not clear, as they were considered as continent of urine in the included studies.

CONCLUSION

Further research is needed to elucidate the mechanisms of how bacteria, in combination with urine, lead to IAD.

Biofilm-Innate Immune Interface: Contribution to Chronic Wound Formation

Delayed wound healing can cause significant issues for immobile and ageing individuals as well as those living with co-morbid conditions such as diabetes, cardiovascular disease, and cancer. These delays increase a patient’s risk for infection and, in severe cases, can result in the formation of chronic, non-healing ulcers (e.g., diabetic foot ulcers, surgical site infections, pressure ulcers and venous leg ulcers). Chronic wounds are very difficult and expensive to treat and there is an urgent need to develop more effective therapeutics that restore healing processes. Sustained innate immune activation and inflammation are common features observed across most chronic wound types. However, the factors driving this activation remain incompletely understood. Emerging evidence suggests that the composition and structure of the wound microbiome may play a central role in driving this dysregulated activation but the cellular and molecular mechanisms underlying these processes require further investigation. In this review, we will discuss the current literature on: 1) how bacterial populations and biofilms contribute to chronic wound formation, 2) the role of bacteria and biofilms in driving dysfunctional innate immune responses in chronic wounds, and 3) therapeutics currently available (or underdevelopment) that target bacteria-innate immune interactions to improve healing. We will also discuss potential issues in studying the complexity of immune-biofilm interactions in chronic wounds and explore future areas of investigation for the field.

Burden of perianal Staphylococcus aureus colonization in nursing home residents increases transmission to healthcare worker gowns and gloves

OBJECTIVE

To evaluate the effect of the burden of Staphylococcus aureus colonization of nursing home residents on the risk of S. aureus transmission to healthcare worker (HCW) gowns and gloves.

DESIGN

Multicenter prospective cohort study.

SETTING AND PARTICIPANTS

Residents and HCWs from 13 community-based nursing homes in Maryland and Michigan.

METHODS

Residents were cultured for S. aureus at the anterior nares and perianal skin. The S. aureus burden was estimated by quantitative polymerase chain reaction detecting the nuc gene. HCWs wore gowns and gloves during usual care activities; gowns and gloves were swabbed and then cultured for the presence of S. aureus.

RESULTS

In total, 403 residents were enrolled; 169 were colonized with methicillin-resistant S. aureus (MRSA) or methicillin-sensitive S. aureus (MSSA) and comprised the study population; 232 were not colonized and thus were excluded from this analysis; and 2 were withdrawn prior to being swabbed. After multivariable analysis, perianal colonization with S. aureus conferred the greatest odds for transmission to HCW gowns and gloves, and the odds increased with increasing burden of colonization: adjusted odds ratio (aOR), 2.1 (95% CI, 1.3-3.5) for low-level colonization and aOR 5.2 (95% CI, 3.1-8.7) for high level colonization.

CONCLUSIONS

Among nursing home patients colonized with S. aureus, the risk of transmission to HCW gowns and gloves was greater from those colonized with greater quantities of S. aureus on the perianal skin. Our findings inform future infection control practices for both MRSA and MSSA in nursing homes.