How Does Time Affect the Antimicrobial Activity of Super-Oxidized Commercial Antiseptic Solutions? An In Vitro Test

This study aimed to identify variation in the minimum biocidal concentration (MBC) over time, comparing three commercial super-oxidized solutions with different chemical compositions. In the bactericidal assay, the following bacteria were tested: Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923), and for each ATCC, one wild-type strain was used. In vitro experiments were performed in triplicate at 0, 60, and 120 days of follow up. A commercial formulation based on sodium and chloride ions (SCSS) was tested using a standard accelerated aging protocol. Data were analyzed with the Friedman and Wilcoxon signed-rank tests. The results showed that super-oxidized solution bases of 20 ppm of sodium (SSS) had a significant change in MBC at 120 days (p < 0.001), whereas SCSS remained stable during the same period (p = 0.18). However, after accelerated aging treatment, the MBC of SCSS increased (p < 0.001). With our proposed approach, the two SSS showed MBC variation at 120 days, whereas SCSS showed stability over time, similar to chlorhexidine, but lost its bactericidal properties after accelerated aging treatment.

Medical Applications of Hydrogels in Skin Infections: A Review

Skin infections are common diseases for which patients seek inpatient and outpatient medical care. Globally, an increasing number of people are affected by skin infections that could lead to physical and psychological damage. Skin infections always have a broad spectrum of clinical presentations that require physicians to make an aggressive and accurate diagnosis for prescribing the proper symptomatic antimicrobials. In most instances, the treatment for skin infections mainly includes oral or topical anti-infective drugs. However, some of the classical anti-infective drugs have limitations, such as poor water solubility, low bioavailability, and poor targeting efficiency, which can lead to poor efficacy, adverse effects, and drug resistance. Therefore, research priorities should focus on the development of more effective drug delivery systems with new materials. Hydrogels are a highly multifunctional class of medical materials with potential applications in dermatology. Several hydrogel dressings with anti-infective functions have been formulated and demonstrated to improve the efficacy and tolerance of oral or topical classical anti-infective drugs to a certain degree. In this study, the medical applications of hydrogels for the treatment of various skin infections are systematically reviewed to provide an important theoretical reference for future research studies on the treatment options for skin infections.

Management of infection prophylaxis in Dutch patients with myelodysplastic syndromes, a web-based case vignette questionnaire: the MINDSET study

Objectives

Infections are a major cause of morbidity and mortality in patients with myelodysplastic syndromes (MDS). The objective of the MINDSET study was to evaluate haematologists' management of infection prevention in MDS patients using a case vignette study and to assess the availability of guidelines.

Methods

We conducted a web‐based, nationwide survey amongst haematologists in the Netherlands between September and December 2021. The survey included a set of case vignettes. In addition, the availability of protocols was evaluated.

Results

Sixty responses were obtained (23.6%). These responses were well distributed across hospital types as well as level of experience. No protocols regarding infection prophylaxis specifically for MDS patients were received. In the case vignette of a 75‐year‐old MDS patient, respondents would primarily prescribe infection prophylaxis in case of recurrent infections (96.7%) and neutropenia (75.0% for absolute neutrophil count [ANC] < 0.2 × 10⁹/L and 53.3% for ANC < 0.5 × 10⁹/L), especially in combination with hypomethylating agents (80.0%), lenalidomide (66.7%) or chemotherapy (51.7%). Respondents would predominantly choose antibacterial agents (85.0%), followed by antifungal agents (71.7%).

Conclusions

This study showed diverse reasons and considerations of haematologists regarding whether to prescribe infection prophylaxis in MDS patients. Given the seriousness of infections in MDS patients, patient‐tailored recommendations might be valuable in clinical decision‐making.

Challenges with Wound Infection Models in Drug Development

Wound research is an evolving science trying to unfold the complex untold mechanisms behind the wound healing cascade. In particular, interest is growing regarding the role of microorganisms in both acute and chronic wound healing. Microbial burden plays an important role in the persistence of chronic wounds, ultimately resulting in delayed wound healing. It is therefore important for clinicians to understand the evolution of infection science and its various etiologies. Therefore, to understand the role of bacterial biofilm in chronic wound pathogenesis, various in vitro and in vivo models are required to investigate biofilms in wound-like settings. Infection models should be refined comprising an important signet of biofilms. These models are eminent for translational research to obtain data for designing an improved wound care formulation. However, all the existing models possess limitations and do not fit properly in the model frame for developing wound care agents. Among various impediments, one of the major drawbacks of such models is that the wound they possess does not mimic the wound a human develops. Therefore, a novel wound infection model is required which can imitate the human wounds. This review article mainly discusses various in vitro and in vivo models showing microbial colonization, their advantages and challenges. Apart from these models, there are also present ex vivo wound infection models, but this review mainly focused on various in vitro and in vivo models available for studying wound infection in controlled conditions. This information might be useful in designing an ideal wound infection model for developing an effective wound healing formulation.

Anacardium excelsum phytochemical analysis and in vitro antimicrobial activity against oral cavity microorganisms

Infections of the oral cavity have a broad microbial etiological profile that varies according to each microenvironment in the mouth. Such infections often require antimicrobial treatment, which can lead to the development of resistance. There is thus a need to find new therapeutic strategies based on natural plant-derived compounds. The aim of this study was to determine the phytochemical nuclei and the antimicrobial effect of Anacardium excelsum leaf and stem extracts, and of fractions derived from the leaf extract, against Streptococcus mutans ATCC 25175, Staphylococcus aureus ATCC 35548, Escherichia coli ATCC 25922, Enterococcus faecalis ATCC 19433 and Candida albicans ATCC 10231. The plant material was collected from the Quindío Botanical Garden (Calarcá, Quindío-Colombia), located at an altitude of 1500 meters above sea level. Hydroalcoholic extracts of A. excelsum leaves and stems, and fractions of the hydroalcoholic leaf extract, were obtained by percolation extraction. Phytochemical nuclei were identified by thin layer chromatography. The antimicrobial activity of the extracts and fractions (at concentrations of 2, 5, 10, 20 and 40 mg / ml) against the five ATCC reference strains was evaluated using the well diffusion technique on Mueller-Hinton agar. The leaf extract showed no antimicrobial activity against E. coli, but it did show antimicrobial activity against S. mutans, S. aureus, E. faecalis and C. albicans, at a concentration of 10 mg/ml, with zones of inhibition of 9 to 11 mm. The ethyl acetate and acetone fractions obtained from A. excelsum leaf extract had greatest antimicrobial activity at 10 mg/ml. In conclusion, (1) the A. excelsum leaf extract, and the ethyl acetate and acetone fractions obtained from the leaf extract, had the greatest antimicrobial activity on all the study microorganisms, and (2) the phytochemical nuclei in the fractions (ethyl acetate and acetone) were found to contain phenolic-type compounds, tannins, triterpene-type terpenes and steroidal-type terpenes, which might explain the antimicrobial activity observed.

Use of T Cell Mediated Immune Functional Assays for Adjustment of Immunosuppressive or Anti-infective Agents in Solid Organ Transplant Recipients: A Systematic Review

Background: Defining the optimal dosage of the immunosuppressive or duration of anti-infective agents is a challenge in solid organ transplant (SOT) recipients. We aimed to systematically review the literature regarding the use of T cell mediated immune functional assays (IFAs) for adjustment of the immunosuppressive or anti-infective agents in SOT recipients. Methods: We systematically searched PubMed, Scopus, EMBASE, Web of Science (WOS), Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov to find human interventional studies or study protocols that used either in-house or commercially available IFAs for adjustment of the immunosuppressive or anti-infective agents in SOT recipients. Results: We included six clinical trials and six study protocols. Four out of the six clinical trials used interferon-γ release assays for cytomegalovirus (IGRA-CMV), and five out of the six registered study protocols planned to use IGRA-CMV for adjustment of anti-CMV antiviral (Valganciclovir) prophylaxis or preemptive therapy in SOT recipients. Primary or secondary anti-CMV prophylaxes were discontinued in SOT recipients who had positive IGRA-CMV results without an increase in the rate of CMV infection or reactivation. Among other IFAs, one clinical trial used interferon-γ release assays for tuberculosis (IGRA-TB), and one study used ImmuKnow for adjustment of the duration and dosage of isoniazid and tacrolimus, respectively. Conclusion: Our systematic review supports a promising role for the IGRA-CMVs for adjustment of the duration of anti-CMV antiviral prophylaxis in SOT recipients. There are limited data to support the use of IFAs other than IGRA-CMVs for adjustment of immunosuppressive or anti-infective agents. Further multicenter randomized clinical trials using IFAs other than IGRA-CMVs may help in personalized immunosuppressive or prophylactic anti-infective therapy in SOT recipients.

Multi Dynamic Extraction: An Innovative Method to Obtain a Standardized Chemically and Biologically Reproducible Polyphenol Extract from Poplar-Type Propolis to Be Used for Its Anti-Infective Properties

Antimicrobial activity is a well-known property of propolis, making it a candidate for antimicrobial surfaces in biomedical devices. Nevertheless, large-scale use of propolis as an anti-infective agent is limited by the heterogeneity of its chemical composition and consequent variation in antimicrobial activity. The aim of this study was to demonstrate that the multi dynamic extraction (M.E.D.) method produces standardized polyphenolic mixtures from poplar-type propolis, with reproducible chemical composition and anti-microbial activity, independently from the chemical composition of the starting raw propolis. Three raw propolis samples, from Europe, America, and Asia, were analyzed for their polyphenol chemical composition by means of HPLC-UV and then combined to obtain three mixtures of propolis, which werme submitted to the M.E.D. extraction method. The chemical composition and the antimicrobial activity of M.E.D. propolis against bacteria and fungi were determined. The three M.E.D. propolis showed similar chemical compositions and antimicrobial activities, exhibiting no relevant differences against antibiotic-susceptible and antibiotic-resistant strains. The batch-to-batch reproducibility of propolis extracts obtained with the M.E.D. method encourages the design of drugs alternative to traditional antibiotics and the development of anti-infective surface-modified biomaterials.

Antisense peptide nucleic acids as a potential anti-infective agent

Antibiotics have long been used for anti-infective control of bacterial infections, growth promotion in husbandry, and prophylactic protection against plant pathogens. However, their inappropriate use results in the emergence and spread of multiple drug resistance (MDR) especially among various bacterial populations, which limits further administration of conventional antibiotics. Therefore, the demand for novel anti-infective approaches against MDR diseases becomes increasing in recent years. The peptide nucleic acid (PNA)-based technology has been proposed as one of novel anti-infective and/or therapeutic strategies. By definition, PNA is an artificially synthesized nucleic acid mimic structurally similar to DNA or RNA in nature and linked one another via an unnatural pseudo-peptide backbone, rendering to its stability in diverse host conditions. It can bind DNA or RNA strands complimentarily with high affinity and sequence specificity, which induces the target-specific gene silencing by inhibiting transcription and/or translation. Based on these unique properties, PNA has been widely applied for molecular diagnosis as well as considered as a potential anti-infective agent. In this review, we discuss the general features of PNAs and their application to various bacterial pathogens as new anti-infective or antimicrobial agents.

Impact of clinical decision support on empirical antibiotic prescribing for children with community-acquired pneumonia

AIM

To assess the impact of a computerised clinical decision support system (CDSS) on antibiotic use in hospitalised children with a presumptive diagnosis of uncomplicated community-acquired pneumonia (CAP).

METHODS

Codes associated with lower respiratory tract infection were used to identify cases of presumed uncomplicated CAP requiring admission to a tertiary paediatric hospital. Random sampling of the periods between 1 October 2010 and 30 September 2012 (pre-CDSS) and 1 October 2012 and 30 September 2014 (post-CDSS) determined the sequence of case assessment by two independent investigators. Initial antibiotic therapy, associated CDSS approvals and documented signs of clinical deterioration prior to antibiotic decision-making were recorded.

RESULTS

Statistically significant differences between cases pre- and post-CDSS implementation were minimal. High fever was observed in 57.5% (77/134) cases pre-CDSS and 45.8% (49/107) cases post-CDSS (P = 0.07). Supplemental oxygen was used in 30.6% pre-CDSS and 54.2% post-CDSS cases (P < 0.001). Narrow-spectrum penicillins were prescribed most often, with no statistically significant change post-CDSS implementation (81.3% pre-CDSS, 77.6% post-CDSS, P = 0.47). Macrolides were used consistently throughout the study period (53.7% pre-CDSS, 61.7% post-CDSS; P = 0.21).

CONCLUSION

CDSS implementation did not reduce already low rates of broad-spectrum antibiotic use for uncomplicated CAP.

Does periurethral cleaning with water prior to indwelling urinary catheterization increase the risk of urinary tract infections? A systematic review and meta-analysis

OBJECTIVE

To determine whether periurethral cleaning with water before indwelling urinary catheterization increases the risk of urinary tract infections (UTIs) compared with studies using anti-infective agents.

METHODS

A literature search via MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials through October 2017 and a manual search of references for additional relevant studies. Trials studying clean intermittent catheterization were excluded. Data were extracted independently by 2 reviewers. Disagreements were resolved through discussion. Results of randomized controlled trials were pooled using random effects models. Both individual and pooled risk estimates were reported using risk ratios (RRs) and 95% confidence intervals (CIs).

RESULTS

From 121 identified articles, 5 studies involving 824 patients were included in the review (822 patients included in meta-analysis). No statistical significance in the incidence of UTIs existed between the water group and antiseptics group (RR, 1.07; 95% CI, 0.77-1.49; P = .89; I² = 0%). Available data comparing water with povidone-iodine or chlorhexidine gluconate demonstrated no significant difference between the incidence of UTIs (RR, 1.10; 95% CI, 0.66-1.83; P = .79; I² = 0%; and RR, 1.05; 95% CI, 0.68-1.62; P = .72; I² = 0%; respectively).

CONCLUSIONS

Based on current data, water is as safe as other topical antiseptics for periurethral cleansing before indwelling urinary catheter insertion.

Sticking to minimum standards: implementing antibiotic stewardship in intensive care

BACKGROUND

In Australia, antimicrobial stewardship programmes are a compulsory component of hospital accreditation. Good documentation around anti-microbial prescribing aids communication and can improve prescribing practice in environments with multiple decision makers.

AIM

This study aims to develop and implement an intervention to improve antimicrobial prescribing practice in a 24-bed intensive care unit in a tertiary referral adult hospital.

METHODS

We conducted a four-phase (observation, reflection, implementation, evaluation) prospective collaborative before-after quality improvement study. Baseline audits and surveys of antimicrobial prescribing practices identified barriers to and enablers of good prescribing practice. A customised intervention was then implemented over 6 weeks and included a yellow medication record sticker, quarterly education sessions and intensive care unit-specific empiric antimicrobial prescribing guidelines. Post-implementation, the effects were monitored by serial antimicrobial prescribing audits for 1 year. The primary outcomes were clear documentation of the start date, the planned stop date or review date and the indication for an antibiotic. These were all considered the 'minimum standards' for an antimicrobial prescription on the medication record.

RESULTS

Documentation of minimum standards specifically addressed by the sticker improved (start date (72% to 90%, P < 0.001), stop date (16% to 63%, P < 0.001), antimicrobial indication documented on medication chart (58% to 83%, P < 0.01)). Overall, adherence to all three minimum standards (start date, stop date and indication) improved from 41/306 (13%) to 306/492 (63%) (P < 0.001). One-year post-implementation, the yellow sticker had become embedded into daily practice.

CONCLUSION

A systematic approach to quality improvement combined with the implementation of a tailored, multi-faceted intervention can improve antimicrobial prescribing practices.