Neomycin 0.25% / Gramicidin 0.025% ointment

What is known and objectiveThe overuse and misuse of antibiotics, especially for viral, and self-limiting, respiratory tract infections such as sore throat, increases the risk of the development and spread of antimicrobial resistance within communities. Up to 80% of sore throat cases have a viral aetiology, and even when the infection is bacterial, most cases resolve without antibiotics. However, antibiotics are still frequently and often inappropriately prescribed for the treatment of sore throat. Furthermore, topical (local) antibiotics for treatment of sore throat are widely available over the counter. The objective of this systematic review was to establish the evidence for the benefits, risk of harm and antimicrobial resistance associated with topical (local) antibiotics used for patients with sore throat.MethodsEligible studies included those in patients with sore throat of any aetiology receiving the topical (local) antibiotics tyrothricin, bacitracin, gramicidin or neomycin where the antibiotic was topically/locally applied via the nasal cavity or throat. Nasal applications were included as these are occasionally used to treat upper respiratory tract infections that may involve sore throat. There was no restriction or requirement regarding comparator. The outcomes of interest included efficacy, safety, and in vitro culture and antimicrobial resistance data.Results and discussionThis systematic review found sparse and mainly poor-quality evidence relating to the use of topical (local) antibiotics for sore throat, and it was not possible to establish the benefits, risk of harm or impact of use on antimicrobial resistance.What is new and conclusionsFurther research is necessary to ascertain the risks and benefits of topical (local) antibiotics, their contribution to antimicrobial resistance and the risk of harm. We do, however, question whether it is appropriate and rational to use topical (local) antibiotics for the treatment of sore throat caused by respiratory tract infections in the absence of robust evidence.

Abstract licence: CC BY-NC

BackgroundTopical steroids are used widely to manage excessive inflammation and hypergranulation in burns; however, their use is controversial, and current evidence is largely anecdotal. Topical KENACOMB is a steroid preparation consisting of triamcinolone acetonide, neomycin, gramicidin, and nystatin, and it is standard of care at the Royal Brisbane and Women's Hospital burns unit. To our knowledge, there is no published literature that reports the use of KENACOMB to treat wound-associated inflammation and hypergranulation.ObjectiveTo synthesise current evidence surrounding the efficacy and safety of topical steroid use in treating inflammation and hypergranulation in burns patients. We also describe the use of topical KENACOMB in our burns unit.MethodsA systematic review of PubMed, Cochrane, and EMBASE databases was performed. Articles published in English that reported the use of topical steroids for granulation tissue or inflammation in burn wounds or skin graft donor sites were included.ResultsWe identified 350 articles, of which six met inclusion criteria. Four studies presented primary patient data, and two studies reported the results of surveys of burns unit professionals. A total of 54 patients were included across all studies, and no control group was reported in any study. Studies reported rapid improvements in healing, with 86.6%-100% of wounds showing complete reepithelialisation following treatment. Reported adverse outcomes included skin thinning, atrophy of granulation tissue, systemic side effects, and local wound infection.ConclusionsThis review highlights the paucity of conclusive evidence on the outcomes of topical steroids in treating inflammation and hypergranulation in burns and donor sites. While KENACOMB has shown efficacy in treating these wound types in our local experience, there is limited research available on the product. There is a clear need for quality research on the use of topical steroids in burns patients to better inform its ongoing clinical use.

Abstract licence: CC BY-NC-ND

Using free microorganisms for industrial processes has some limitations, such as the extensive consumption of substrates for growth, significant sensitivity to the microenvironment, and the necessity of separation from the product and, therefore, the cyclic process. It is widely acknowledged that confining or immobilizing cells in a matrix or support structure enhances enzyme stability, facilitates recycling, enhances rheological resilience, lowers bioprocess costs, and serves as a fundamental prerequisite for large-scale applications. This report summarizes the various cell immobilization methods, including several synthetic (polyvinylalcohol, polyethylenimine, polyacrylates, and Eudragit) and natural (gelatin, chitosan, alginate, cellulose, agar-agar, carboxymethylcellulose, and other polysaccharides) polymeric materials in the form of thin films, hydrogels, and cryogels. Advancements in the production of well-known antibiotics like penicillin and cephalosporin by various strains were discussed. Additionally, we highlighted cutting-edge research related to strain producers of peptide-based antibiotics (polymyxin B, Subtilin, Tyrothricin, varigomycin, gramicidin S, friulimicin, and bacteriocin), glusoseamines, and polyene derivatives. Crosslinking agents, especially covalent linkers, significantly affect the activity and stability of biocatalysts (penicillin G acylase, penicillinase, deacetoxycephalosporinase, L-asparaginase, β-glucosidase, Xylanase, and urease). The molecular weight of polymers is an important parameter influencing oxygen and nutrient diffusion, the kinetics of hydrogel formation, rigidity, rheology, elastic moduli, and other mechanical properties crucial for long-term utilization. A comparison of stability and enzymatic activity between immobilized enzymes and their free native counterparts was explored. The discussion was not limited to recent advancements in the biopharmaceutical field, such as microorganism or enzyme immobilization, but also extended to methods used in sensor and biosensor applications. In this study, we present data on the advantages of cell and enzyme immobilization over microorganism (bacteria and fungi) suspension states to produce various bioproducts and metabolites-such as antibiotics, enzymes, and precursors-and determine the efficiency of immobilization processes and the optimal conditions and process parameters to maximize the yield of the target products.

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Currently, Gramicidin S (GR-S) is produced enzymatically with the drawback of the presence of trifluoroacetic acid (TFA) or produced by fermentation involving several separation and purification steps. Therefore, this study is focused on the use of green solvents as unique extraction step to produce Gramicidin S from microbial biomass of Aneurinibacillus aneurinilyticus. Among the tested solvents, such as ethanol, acidic ethanol or buffer phosphate, the most favorable was acidic ethanol, extracting 96% of Gramicidin S from cells with a purity of 90%. Using acidic ethanol, extraction time within the range of 30-120 min exhibited minimal impact on Gramicidin S yield, whereas the biomass-to-extractant ratio emerged as a critical parameter. Gramicidin S extracts were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF-MS), and Electrospray Ionization Mass Spectrometry (ESI-MS) coupled with Ultra Performance Liquid Chromatography (UPLC) and compared with commercial Gramicidin S.

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The dosage form iotrim (gramicidin, neomycin and triamcinolone) is a combination of two antibiotics (gramicidin and neomycin) and a steroid (triamcinolone). The antibiotics work by killing the bacteria that cause infections. The steroid blocks the action of chemical messengers (prostaglandins) that make the affected area red, swollen and itchy. Consequently, there was still a need to develop a simple, less time consuming and economical method for the simultaneous determination of gramicidin, neomycin and triamcinolone acetonide. The current work is an effort to develop a fast and reproducible LC-MS technique for the simultaneous estimation of gramicidin, neomycin and triamcinolone acetonide. The objective of the present procedure was to validate and develop a precise and accurate liquid chromatography-mass spectrometry (LC-MS) technique for the simultaneous quantification of gramicidin, neomycin and triamcinolone acetonide. Gramicidin, neomycin and triamcinolone acetonide were monitored on Shimadzu-8045 mass spectrometer equipped with electro spray ionization interface. The retention times of gramicidin, neomycin and triamcinolone acetonide were found at 9.145 min, 7.273 min and 2.435 min, respectively. The limit of detection (LOD) results for gramicidin, neomycin and triamcinolone acetonide were observed to be 0.15, 1.5 and 0.6 μg/mL, respectively while the limit of quantification (LOQ) results were observed to be 0.5, 5, 2 μg/mL concentration, respectively. The linear range for gramicidin, neomycin and triamcinolone acetonide were found in the concentration ranges from 1.25-7.5 μg/mL, 12.5-75 μg/mL and 5-30 μg/mL with regression coefficient of 0.9991, 0.9996, 0.9999, respectively. Accuracy values for gramicidin, neomycin and triamcinolone acetonide were found to be in the range of 98.64%, 99.4%, 99.5% respectively. The % RSD for six replicates in precision was less than 2%. According to ICH Q2(R1) recommendations, this method was successfully tested with LC-MS to confirm the chemical structures of newly produced degradation products of triamcinolone acetonide and neomycin. The developed process was validated efficaciously as per ICH guidelines.

Abstract licence: CC BY

AimsThe aims of this study were to explore the development of bacterial resistance and cross-resistance in four common human pathogens following realistic exposure to antibiotics found in over-the-counter (OTC) sore throat medicines: gramicidin, neomycin, bacitracin and tyrothricin.Methods and resultsBacterial exposure to in-use (concentration in the product before use) and diluted concentration (i.e. during use) of antibiotic where conducted in broth for 24 h or until growth was visible. The changes in bacterial susceptibility profile before and after exposure was determined using standardized ISO microdilution broth. Antibiotic testing was performed according to EUCAST guidelines. We demonstrated that test bacteria were able to survive exposure to the in-use concentrations of some antibiotics used in OTC medicines. Exposure to during use concentrations of bacitracin resulted in stable increase in minimal inhibitory concentration (MIC) (>8-fold) in Staphylococcus aureus and Acinetobacter baumannii. Exposure to tyrothricin resulted in a stable increase in MIC (2·4-fold) in Klebsiella pneumoniae, and exposure to neomycin resulted in a stable increase MIC (5000-fold higher than the baseline) in Streptococcus pyogenes. Clinical cross-resistance to other antibiotics (ciprofloxacin, fusidic acid, gentamicin, cefpodoxime, amoxicillin/clavulanic acid and cefotaxime) was also demonstrated following exposure to bacitracin or tyrothricin. Bacitracin exposure lead to a stable bacterial resistance after 10 passages.ConclusionsOur results indicate that OTC antibiotic medicines have the potential to drive resistance and cross-resistance in vitro.Significance and impact of the studyTackling antibiotic resistance is a high worldwide priority. It is widely accepted that the overuse and misuse of antibiotics increase the risk of the development and spread of antibiotic resistance within communities. A number of OTC sore throat products, widely available across the world for topical use in respiratory indications, contain locally delivered antibiotics. Our findings showed that these antibiotics in OTC medicines present a risk for emerging cross-resistance in a number of bacterial respiratory pathogens.

Abstract licence: CC BY