Fabrication and characterization of physically crosslinked alginate/chitosan-based hydrogel loaded with neomycin for the treatment of skin infections caused by Staphylococcus aureus

Staphylococcus aureus is a pathogen widely involved in wound infection due to its ability to release several virulence factors that impair the skin healing process, as well as its mechanism of drug resistance. Herein, sodium alginate and chitosan were combined to produce a hydrogel for topical delivery of neomycin to combat S. aureus associated with skin complications. The hydrogel was formulated by combining sodium alginate (50 mg/mL) and chitosan (50 mg/mL) solutions in a ratio of 9:1 (HBase). Neomycin was added to HBase to achieve a concentration of 0.4 mg/mL (HNeo). The incorporation of neomycin into the product was confirmed by scanning electron microscopy, FTIR and TGA analysis. The hydrogels produced are homogeneous, have a high swelling capacity, and show biocompatibility using erythrocytes and fibroblasts as models. The formulations showed physicochemical and pharmacological stability for 60 days at 4 ± 2 °C. HNeo totally inhibited the growth of S. aureus after 4 h. The antimicrobial effects were confirmed using ex vivo (porcine skin) and in vivo (murine) wound infection models. Furthermore, the HNeo-treated mice showed lower severity scores than those treated with HBase. Taken together, the obtained results present a new low-cost bioproduct with promising applications in treating infected wounds.

Morbidity After Mechanical Bowel Preparation and Oral Antibiotics Prior to Rectal Resection: The MOBILE2 Randomized Clinical Trial

Importance

Surgical site infections (SSIs)-especially anastomotic dehiscence-are major contributors to morbidity and mortality after rectal resection. The role of mechanical and oral antibiotics bowel preparation (MOABP) in preventing complications of rectal resection is currently disputed.

Objective

To assess whether MOABP reduces overall complications and SSIs after elective rectal resection compared with mechanical bowel preparation (MBP) plus placebo.

Design, Setting, and Participants

This multicenter, double-blind, placebo-controlled randomized clinical trial was conducted at 3 university hospitals in Finland between March 18, 2020, and October 10, 2022. Patients aged 18 years and older undergoing elective resection with primary anastomosis of a rectal tumor 15 cm or less from the anal verge on magnetic resonance imaging were eligible for inclusion. Outcomes were analyzed using a modified intention-to-treat principle, which included all patients who were randomly allocated to and underwent elective rectal resection with an anastomosis.

Interventions

Patients were stratified according to tumor distance from the anal verge and neoadjuvant treatment given and randomized in a 1:1 ratio to receive MOABP with an oral regimen of neomycin and metronidazole (n = 277) or MBP plus matching placebo tablets (n = 288). All study medications were taken the day before surgery, and all patients received intravenous antibiotics approximately 30 minutes before surgery.

Main Outcomes and Measures

The primary outcome was overall cumulative postoperative complications measured using the Comprehensive Complication Index. Key secondary outcomes were SSI and anastomotic dehiscence within 30 days after surgery.

Results

In all, 565 patients were included in the analysis, with 288 in the MBP plus placebo group (median [IQR] age, 69 [62-74] years; 190 males [66.0%]) and 277 in the MOABP group (median [IQR] age, 70 [62-75] years; 158 males [57.0%]). Patients in the MOABP group experienced fewer overall postoperative complications (median [IQR] Comprehensive Complication Index, 0 [0-8.66] vs 8.66 [0-20.92]; Wilcoxon effect size, 0.146; P < .001), fewer SSIs (23 patients [8.3%] vs 48 patients [16.7%]; odds ratio, 0.45 [95% CI, 0.27-0.77]), and fewer anastomotic dehiscences (16 patients [5.8%] vs 39 patients [13.5%]; odds ratio, 0.39 [95% CI, 0.21-0.72]) compared with patients in the MBP plus placebo group.

Conclusions and Relevance

Findings of this randomized clinical trial indicate that MOABP reduced overall postoperative complications as well as rates of SSIs and anastomotic dehiscences in patients undergoing elective rectal resection compared with MBP plus placebo. Based on these findings, MOABP should be considered as standard treatment in patients undergoing elective rectal resection.

Trial Registration

ClinicalTrials.gov Identifier: NCT04281667.

Intranasal neomycin evokes broad-spectrum antiviral immunity in the upper respiratory tract

Respiratory virus infections in humans cause a broad-spectrum of diseases that result in substantial morbidity and mortality annually worldwide. To reduce the global burden of respiratory viral diseases, preventative and therapeutic interventions that are accessible and effective are urgently needed, especially in countries that are disproportionately affected. Repurposing generic medicine has the potential to bring new treatments for infectious diseases to patients efficiently and equitably. In this study, we found that intranasal delivery of neomycin, a generic aminoglycoside antibiotic, induces the expression of interferon-stimulated genes (ISGs) in the nasal mucosa that is independent of the commensal microbiota. Prophylactic or therapeutic administration of neomycin provided significant protection against upper respiratory infection and lethal disease in a mouse model of COVID-19. Furthermore, neomycin treatment protected Mx1 congenic mice from upper and lower respiratory infections with a highly virulent strain of influenza A virus. In Syrian hamsters, neomycin treatment potently mitigated contact transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In healthy humans, intranasal application of neomycin-containing Neosporin ointment was well tolerated and effective at inducing ISG expression in the nose in a subset of participants. These findings suggest that neomycin has the potential to be harnessed as a host-directed antiviral strategy for the prevention and treatment of respiratory viral infections.

Design and characterization of 3D printed, neomycin-eluting poly-L-lactide mats for wound-healing applications

This study evaluates the suitability of 3D printed biodegradable mats to load and deliver the topical antibiotic, neomycin, for up to 3 weeks in vitro. A 3D printer equipped with a hot melt extruder was used to print bandage-like wound coverings with porous sizes appropriate for cellular attachment and viability. The semicrystalline polyester, poly-l-lactic acid (PLLA) was used as the base polymer, coated (post-printing) with polyethylene glycols (PEGs) of MWs 400 Da, 6 kDa, or 20 kDa to enable manipulation of physicochemical and biological properties to suit intended applications. The mats were further loaded with a topical antibiotic (neomycin sulfate), and cumulative drug-release monitored for 3 weeks in vitro. Microscopic imaging as well as Scanning Electron Microscopy (SEM) studies showed pore dimensions of 100 × 400 µm. These pore dimensions were achieved without compromising mechanical strength; because of the "tough" individual fibers constituting the mat (Young's Moduli of 50 ± 20 MPa and Elastic Elongation of 10 ± 5%). The in vitro dissolution study showed first-order release kinetics for neomycin during the first 20 h, followed by diffusion-controlled (Fickian) release for the remaining duration of the study. The release of neomycin suggested that the ability to load neomycin on to PLLA mats increases threefold, as the MW of the applied PEG coating is lowered from 20 kDa to 400 Da. Overall, this study demonstrates a successful approach to using a 3D printer to prepare porous degradable mats for antibiotic delivery with potential applications to dermal regeneration and tissue engineering. Illustration of the process used to create and characterize 3D printed PLLA mats.

Oral decontamination with colistin plus neomycin in solid organ transplant recipients colonized by multidrug-resistant Enterobacterales: a multicentre, randomized, controlled, open-label, parallel-group clinical trial

OBJECTIVES

To evaluate the efficacy of oral colistin-neomycin in preventing multidrug-resistant Enterobacterales (MDR-E) infections in solid organ transplant (SOT) recipients.

METHODS

Multicentre, open-label, parallel-group, controlled trial with balanced (1:1) randomization in five transplant units. SOT recipients were screened for MDR-E intestinal colonization (extended-spectrum β-lactamase or carbapenemase producing) before transplantation and +7 and + 14 days after transplantation and assigned 1:1 to receive treatment with colistin sulfate plus neomycin sulfate for 14 days (decolonization treatment (DT) group) or no treatment (no decolonization treatment (NDT) group). The primary outcome was diagnosis of an MDR-E infection. Safety outcomes were appearance of adverse effects, mainly diarrhoea, rash, nausea and vomiting. Patients were monitored weekly until 30 days after treatment. Intention-to-treat analysis was performed.

RESULTS

MDR-E rectal colonization was assessed in 768 SOT recipients; 105 colonized patients were included in the clinical trial, 53 receiving DT and 52 NDT. No significant decrease in the risk of infection by MDR-E was observed in the DT group (9.4%, 5/53) compared to the NDT group (13.5%, 7/52) (relative risk 0.70; 95% confidence interval 0.24-2.08; p 0.517). Four patients (5.6%), three (5.6%) in the DT group and one (1.9%) in the NDT group, developed colistin resistance. Twelve patients (22.7%) in the DT group had diarrhoea, eight related to treatment (15.0%); one patient (1.8%) developed skin rash and another (1.8%) nausea and vomiting. Two patients (3.8%) in the NDT group developed diarrhoea.

CONCLUSIONS

DT does not reduce MDR-E infections in SOT. Colistin resistance and adverse effects such as diarrhoea are a potential issue that must be taken seriously.

Cytotoxic effect of aminoglycoside antibiotics on the mammalian cell lines

Aminoglycoside antibiotics have been used for treating serious but also routine infections in veterinary and human medicine for many years. The basic aim of this work is to evaluate the cytotoxicity of dihydrostreptomycin and neomycin in vitro on three cell cultures - BHK-21 (Syrian golden hamster kidney fibroblast), VERO (African green monkey kidney fibroblast) and FEA (feline embryonic fibroblast) cells. The morphological changes were examined by Giemsa staining. Cells were dried and visualized under fluorescence microscope. After the exposure to different experimental doses of dihydrostreptomycin (812.5-20000 µg/mL) and neomycin (1000-20000 µg/mL) during 24 h, the viability of BHK-21, FEA and VERO cell lines were evaluated by MTT assay. Viability of BHK-21 cells significantly (P < 0.001) decreased after treatment with 3500; 5500 and 7500 µg/mL of dihydrostreptomycin and 9000; 10000 and 20000 µg/mL of neomycin. The FEA cell viability decreased significantly (P < 0.001; P < 0.01) at 2500 and 3000 µg/mL dihydrostreptomycin and at 3000 µg/mL of neomycin treatment. Only the highest concentration of dihydrostreptomycin (20000 µg/mL) reduced VERO cell viability significantly (P < 0.01). Based on or results we can assume the effect of different antibiotics in different concentrations on cell lines is various. Detection of antibiotic toxicity to animal cells is very important because of the increasing resistance of bacteria. One of the solutions is drug dose increasing, but only to a certain concentration, since the toxic effect over the therapeutic one will prevail, which we have also shown in this work.

Evaluation of the bacterial ocular surface microbiome in clinically normal horses before and after treatment with topical neomycin-polymyxin-bacitracin

Next generation sequencing (NGS) studies have demonstrated a rich and diverse ocular surface-associated microbiota in people that was previously undetected by traditional culture-based methods. The ocular surface microbiome of horses has yet to be investigated using NGS techniques. This study aimed to determine the bacterial composition of the ocular surface microbiome in healthy horses, and to identify whether there are microbial community changes over time and following topical antibiotic use. One eye of 12 horses was treated 3 times daily for 1 week with neomycin-polymyxin-bacitracin ophthalmic ointment. Contralateral eyes served as untreated controls. The inferior conjunctival fornix of both eyes was sampled at baseline prior to initiating treatment (day 0), after 1 week of treatment (day 7), and 4 weeks after concluding treatment (day 35). Genomic DNA was extracted from ocular surface swabs and sequenced using primers that target the V4 region of bacterial 16S rRNA. At baseline, the most abundant phyla identified were Proteobacteria (46.1%), Firmicutes (24.6%), Actinobacteria (12.6%), and Bacteroidetes (11.2%). The most abundant families included Pasteurellaceae (13.7%), Sphingomonadaceae (7.9%), an unclassified Order of Cardiobacteriales (7.7%), and Moraxellaceae (4.8%). Alpha and beta diversity measurements were unchanged in both treatment and control eyes over time. Overall, the major bacterial taxa on the equine ocular surface remained stable over time and following topical antibiotic therapy.

Combination of oral nonabsorbable and intravenous antibiotics versus intravenous antibiotics alone in the prevention of surgical site infections after elective colorectal surgery in pediatric patients: A retrospective study

We conducted this study to compare the effectiveness of combined oral nonabsorbable and intravenous antibiotics versus intravenous antibiotics alone in reducing the incidence of surgical site infections following elective colorectal surgery in pediatric patients.Between January 2010 and December 2016, patients from 0 to 14 who underwent elective colorectal surgery were retrospectively analyzed. Based on intravenous antibiotics with and without oral antibiotics, the patients were grouped as OA group (combination of oral nonabsorbable and intravenous antibiotics) or A group (the intravenous antibiotics alone). Neomycin combined with erythromycin was used in OA group. The data collected included demographic data, diagnosis, procedure being performed, operative time, time to first stool, time to removal of the nasogastric tube, time to full enteral feeds, hospital length of stay, and prophylactic antibiotics (days ± standard deviation). The main outcome was the rate of postoperative infectious complications, such as wound infection, anastomotic leak, and intra-abdominal abscess formation.A total of 564 children who underwent elective colorectal surgery were enrolled which consist of OA group (combination of oral nonabsorbable and intravenous antibiotics) and A group (the intravenous antibiotics alone), the number of the former one was 216 and the latter one was 348. Postoperative complications were similar in both groups of patients. In the OA group, we observed 5 anastomotic leak, 6 wound infections, and 5 intra-abdominal abscesses. In the A group, we observed 13 anastomotic leak, 9 wound infections, and 11 intra-abdominal abscesses. Analysis with Fisher exact test revealed no statistically significant difference in the incidence of wound infection, anastomotic leak, and intra-abdominal abscess between the 2 groups.The results of our study suggest that omitting oral nonabsorbable antibiotics before elective colorectal surgery in infants and children carries no increased risk of infectious or anastomotic complications.

Comparative Evaluation of the Short-Term Bactericidal Potential of a Steroid-Antibiotic Combination versus Steroid in the Treatment of Chronic Bacterial Blepharitis and Conjunctivitis

The effects of four days' treatment with topical Maxitrol (neomycin sulphate 3500 IU/mL, polymyxin-B sulphate 6000 IU/mL with dexamethasone 0.1%) were compared with those of Maxidex (dexamethasone 0.1% alone) in a double-masked study in 111 patients with bacterial blepharitis or conjunctivitis, 95 of whom were evaluable for efficacy. The majority of patients (N = 80) had chronic blepharitis. Maxitrol treatment resulted in a significantly greater reduction (90%) in bacterial counts and bacterial eradication (50%) compared with Maxidex (34% and 17% respectively). Maxitrol treatment also produced a significantly greater reduction in conjunctival discharge than did Maxidex, while the treatments were equally effective in alleviating other ocular signs and symptoms. It was concluded that use of a fixed dose combination steroid-antibiotic product was more effective for bacterial control and therapeutic efficacy in the treatment of chronic blepharitis and conjunctivitis patients than treatment with steroid alone. However, in the long-term treatment of chronic blepharitis the well-known toxic problems of neomycin sulphate have to be taken into account.

A Comparison of two Ophthalmic Steroid-Antibiotic Combinations after Cataract Surgery

We performed this prospective, randomised, investigator-masked, parallel-group study to compare Fluorometholone-Gentamicin eye drops with Maxitrol (dexamethasone, neomycin, polymyxin B) eye drops in the reduction of ocular bacterial flora and control of ocular inflammation after cataract surgery. One hundred and twelve (FML-Genta 54, Maxitrol 58) patients of both sexes undergoing cataract and posterior chamber lens implant surgery for visually disabling cataract were enrolled in the study and examined pre-operatively and post-operatively on days 1, 6-8 and 24-34. The baseline parameters were similar in the two study groups. The conjunctival bacterial colony count on day 6-8 post-operatively was significantly less on FML-Genta compared with Maxitrol (p = 0.033). There was no statistically significant difference between the two treatments in the degree of intra-ocular inflammation as assessed by flare and cells in the anterior chamber. Both treatments were judged to be equal in the global assessment of the success of therapy and local tolerance by the study patients and doctors. Fluorometholone-gentamicin eye drops were more effective than Maxitrol eye drops in the reduction of ocular bacterial flora while being as well-tolerated and as effective as Maxitrol in the control of ocular inflammation after cataract surgery.

Importance of Adding Neomycin to Metronidazole for Bowel Preparation1

A prospective randomized trial has investigated whether it is necessary to add oral neomycin to oral metronidazole as a means of preventing sepsis in elective colonic resection. Seventy-three patients completed the study; 41 received metronidazole and placebo neomycin and 32 received metronidazole and active neomycin. There was a significant reduction in the incidence of wound infection in patients receiving neomycin and metronidazole (22%) compared with metronidazole alone (51%, P < 0.02). There was also a significant reduction in anaerobic infections in the group receiving metronidazole and neomycin compared with metronidazole alone (P < 0.05). These results indicate that oral metronidazole alone is of no benefit for patients requiring elective colonic operations and that if oral metronidazole is advised it should always be given in combination with oral neomycin.

Guanidinylated Neomycin Conjugation Enhances Intranasal Enzyme Replacement in the Brain

Iduronidase (IDUA)-deficient mice accumulate glycosaminoglycans in cells and tissues and exhibit many of the same neuropathological symptoms of patients suffering from Mucopolysaccharidosis I. Intravenous enzyme-replacement therapy for Mucopolysaccharidosis I ameliorates glycosaminoglycan storage and many of the somatic aspects of the disease but fails to treat neurological symptoms due to poor transport across the blood-brain barrier. In this study, we examined the delivery of IDUA conjugated to guanidinoneomycin (GNeo), a molecular transporter. GNeo-IDUA and IDUA injected intravenously resulted in reduced hepatic glycosaminoglycan accumulation but had no effect in the brain due to fast clearance from the circulation. In contrast, intranasally administered GNeo-IDUA entered the brain rapidly. Repetitive intranasal treatment with GNeo-IDUA reduced glycosaminoglycan storage, lysosome size and number, and neurodegenerative astrogliosis in the olfactory bulb and primary somatosensory cortex, whereas IDUA was less effective. The enhanced efficacy of GNeo-IDUA was not the result of increased nose-to-brain delivery or enzyme stability, but rather due to more efficient uptake into neurons and astrocytes. GNeo conjugation also enhanced glycosaminoglycan clearance by intranasally delivered sulfamidase to the brain of sulfamidase-deficient mice, a model of Mucopolysaccharidosis IIIA. These findings suggest the general utility of the guanidinoglycoside-based delivery system for restoring missing lysosomal enzymes in the brain.

Comparison of 3 Topical Treatments against Ulcerative Dermatitis in Mice with a C57BL/6 Background

Ulcerative dermatitis (UD) is a common condition in C57BL/6 mice and strains with this background. The etiology of UD is unclear but appears to have a genetic component associated with the C57BL/6 strain and has been reported as secondary to a variety of conditions. Treatment is unrewarding, resulting in euthanasia in many cases. In the present study we compared 3 topical treatments against spontaneous UD in mice with a C57BL/6 background. In total, 301 mice of both sexes were included in this study, and the tested treatments comprised bacitracin-neomycin sulfate-polymixin B sulfate ointment twice daily, 10% povidone-iodine ointment plus 1% silver sulfadiazine cream once daily, and 0.005% sodium hypochlorite once daily. Lesion healing was defined as complete skin reepithelialization with or without hair regrowth. Sex, age, lesion location, and type and length of treatment were analyzed by using univariate and multivariate logistic regression. Of the 79 mice treated with triple-antibiotic ointment, 27 (34%) healed, compared with 43 of the 125 (34%) treated with povidone-iodine and sulfadiazine and 69 of the 97 (71%) treated with hypochlorite. Lesion size and treatment with 0.005% sodium hypochlorite were the only significant predictors of healing; all other variables were not statistically significant in multivariate analysis. We conclude that 0.005% sodium hypochlorite is an effective topical treatment alternative for UD in C57BL/6 mice and strains on this background, and a favorable prognosis depends on the early identification and treatment of those lesions.

Infection prophylaxis with silastic sponge explants in retinal detachment surgery

In our animal model, silastic scleral sponges retained bactericidal levels of neomycin sulfate for at least 1 week, when thoroughly infiltrated prior to episcleral placement. This would provide an effective protection against acute buckle infections caused by bacteria contaminating the surgical field. Our clinical experience in 1,081 consecutive scleral buckling procedures substantiates the validity of this conclusion.

Comparative study of the efficacy of different treatment options in patients with chronic blepharitis

OBJECTIVE

To compare the efficacy of 3 treatment options in patients with chronic blepharitis.

METHODOLOGY

An experimental, randomized, controlled study was conducted on 45 patients (female 67%; Mean age: 40.5 years) diagnosed with chronic blepharitis, in order to compare the effectiveness of three treatment options. Group 1: eyelid hygiene with neutral shampoo three times/day; group 2: neutral shampoo eyelid hygiene plus topical metronidazole gel 0.75% twice/day; group 3: neutral eyelid hygiene with shampoo plus neomycin 3.5% and polymyxin 10% antibiotic ointment with 0.5% dexamethasone 3 times/day. The symptoms and signs were assessed by assigning scores from 0: no symptoms and/or signs; 1: mild symptoms and/or signs, 2: moderate symptoms and/or signs; and 3: severe symptoms and/or signs.

RESULTS

A significant improvement was observed in the signs and symptoms in all 3 treatment groups. While groups 1 and 2 had more improvement in all variables studied (P<.05), Group 3 showed no clinical improvement for itching (P=.16), dry eye (P=.29), eyelashes falling (P=.16), and erythema at the eyelid margin (P=.29).

CONCLUSIONS

Shampoo eyelid hygiene neutral and neutral shampoo combined with the use of metronidazole gel reported better hygiene results than neutral shampoo lid with antibiotic ointment and neomycin and polymyxin dexamethasone.

Inhibition of the activation and recruitment of microglia-like cells protects against neomycin-induced ototoxicity

One of the most unfortunate side effects of aminoglycoside (AG) antibiotics such as neomycin is that they target sensory hair cells (HCs) and can cause permanent hearing impairment. We have observed HC loss and microglia-like cell (MLC) activation in the inner ear (cochlea) following neomycin administration. We focused on CX3CL1, a membrane-bound glycoprotein expressed on neurons and endothelial cells, as a way to understand how the MLCs are activated and the role these cells play in HC loss. CX3CL1 is the exclusive ligand for CX3CR1, which is a chemokine receptor expressed on the surface of macrophages and MLCs. In vitro experiments showed that the expression levels of CX3CL1 and CX3CR1 increased in the cochlea upon neomycin treatment, and CX3CL1 was expressed on HCs, while CX3CR1 was expressed on MLCs. When cultured with 1 μg/mL exogenous CX3CL1, MLCs were activated by CX3CL1, and the cytokine level was increased in the cochleae leading to apoptosis in the HCs. In CX3CR1 knockout mice, a significantly greater number of cochlear HCs survived than in wild-type mice when the cochlear explants were cultured with neomycin in vitro. Furthermore, inhibiting the activation of MLCs with minocycline reduced the neomycin-induced HC loss and improved the hearing function in neomycin-treated mice in vivo. Our results demonstrate that CX3CL1-induced MLC activation plays an important role in the induction of HC death and provide evidence for CX3CL1 and CX3CR1 as promising new therapeutic targets for the prevention of hearing loss.

Topical treatment of oral lichen planus with anthocyanins

BACKGROUND

Oxidative stress is involved in oral lichen planus (OLP) pathogenesis; meanwhile anthocyanins are natural antioxidants present in grapes skin.

OBJECTIVES

The aim of this research was to verify the utility of anthocyanins, extracted from grapes skin, for the local treatment of oral lichen planus and to compare it with clobetasol propionate- neomycin -nystatin cream (CP-NN).

STUDY DESIGN

Prospective, non-randomized study, with control group. Fifty-two patients with OLP were included. We divided patients into two categories: erosive oral lichen planus (EOLP) and non erosive oral lichen planus (NEOLP). 38 had EOLP (17 cases and 21 controls) and 14 presented NEOLP types (9 cases and 5 controls).Cases received local treatment with anthocyanins from grapes and controls, were treated with CP-NN. The clinical evolution of patients was followed up during six months.

RESULTS

The patients had a therapeutic response with anthocyanins. This was better than CP-NN treatment for patients with EOLP, in improving the involvement score of the oral mucosa and in the morphometric study of the affected areas. In EOLP there were no statistically significant differences in: therapeutic response time, the evolution of pain, or the relapse rate between the two groups. With respect to the treatment of NEOLP there was improved pain relief in the group treated with anthocyanins. This was not observed with CP-NN. The resting analized variables showed no significant difference with both treatments.

CONCLUSIONS

OLP has a favorable response to local treatment with anthocyanins from grapes. We found an equal to or better response than with CP-NN treatment. Many of our patients have systemic diseases, which may contraindicate the use of steroids. With regard to this particular group, the use of this natural antioxidant present in the diet is considered advantageous.

Topical triple-antibiotic ointment as a novel therapeutic choice in wound management and infection prevention: a practical perspective

Triple-antibiotic ointment (TAO) is a safe and effective topical agent for preventing infections in minor skin trauma. The formulation contains neomycin, polymyxin B and bacitracin in a petrolatum base. TAO is active against the most common disease-causing pathogens found in wounds and on the skin and may be an attractive alternative to oral therapy in select circumstances. Resistance to TAO does not develop readily, and safety studies have shown that the risk of allergic sensitivity to TAO is low. Susceptibility profiles of TAO have remained relatively unchanged since its discovery. Prophylaxis or treatment with TAO should be considered as resistant organisms continue to emerge in the community and hospital setting.

Perivascular delivery of neomycin inhibits the activation of NF-κB and MAPK pathways, and prevents neointimal hyperplasia and stenosis after arterial injury

The nuclear transcription factor kappaB (NF-kappaB) is a cytoplasmic dimer that, as the family of mitogen-activated protein kinase (MAPK), can directly regulate the expression of early genes and genes involved in the stress response, following a variety of physiological or pathological stimuli. Both of them stimulate the transcription of many proteins, which are considered important during inflammation. A crucial role has been assigned to these factors in cellular proliferation and in neointimal hyperplasia secondary to the endothelial lesion of arterial vessels. On the other hand, it has been described that neomycin can have an inhibitory function on tumor cell proliferation, through the inhibition of different intracellular pathways of signaling, among them the NF-kappaB and MAPK pathways. Rat common carotid artery was subjected to balloon angioplasty. Neomycin sulfate (18 mg) was applied using pluronic acid gel on the adventitial surface of the injured vessel. MAPK and NF-kappaB activation was quantified after 24 hours with immunohistochemical staining. Neointimal formation was quantified after 14 days with morphometry. Immunohistochemistry results demonstrating MAPK and NF-kappaB activation reveal that both transcription factors are activated in the media of the control vessel wall. In contrast, the immunoreactivity for MAPK and NF-kappaB in the sections obtained from arteries treated with neomycin over 24 hours was insufficient or nonexistent. Treatment with neomycin on adventitia over 14 days in arteries on which angioplasty was performed shows a neointimal index (intimal area/medial area) decrease of 71% in comparison with arteries that were not treated. The adventitial neomycin treatment over 14 days produces a very significant increase (287.5%; p<0.0001) in the arterial luminal circumference in comparison with arteries treated with vehicle. These results support the theory that neomycin plays an important role against neointimal hyperplasia through the inhibition of MAPK and NF-kappaB activation.

Clearance of nasal Staphylococcus aureus colonization with triple antibiotic ointment

BACKGROUND

The prevalence of Staphylococcus aureus colonization of healthcare workers is reported at 30%, with colonization rates for methicillin-resistant S aureus (MRSA) reported between 2.0% and 8.5% among industrialized nations. The anterior nares are the most frequent colonization site. Mupirocin is the standard of care for nasal S aureus decolonization, with decolonization rates as high as 90%. Staphyloccocal resistance to mupirocin has been described, requiring additional management strategies. In certain situations, triple antibiotic ointment (TAO) may be a suitable alternative for elimination of nasal S aureus colonization.

OBSERVATIONS

Adult healthcare workers within an academic-centered hospital (n=216) were screened via nasal swab with culture for S aureus colonization. Forty-!ve subjects (20.8%) screened positive for S aureus; of these subjects, 3 (1.4%) were positive for MRSA. Of the 45 subjects with positive cultures, 30 completed 5 days of twice-daily intranasal TAO application. One week after treatment, all 30 subjects were reswabbed; 16 (53.3%) showed evidence of decolonization on repeat culture.

CONCLUSIONS

The rate of S aureus colonization of healthcare workers in our study is lower than published rates in industrialized nations. Intranasal application of TAO may be a viable option for eradication of nasal colonization by methicillin-susceptible S aureus in environments where mupirocin-resistant bacterial strains become more prevalent.

Anaphylactic events observed within 4 h of ocular application of an antibiotic-containing ophthalmic preparation: 61 cats (1993-2010)

This study describes signalment, history, antibiotic administered, clinical signs observed, therapy, and outcome of anaphylactic events within 4 h following ophthalmic administration of an antibiotic to cats. Data came from survey responses (45 cats) or Federal Drug Administration reports (16 cats). Cat age (7 weeks-19 years), breed, and gender ranged widely. Most were healthy (87%) prior to anaphylaxis. Ophthalmic antibiotics commonly were administered for conjunctival (65%) or corneal (11%) disease, or ocular lubrication (7%) and contained bacitracin, neomycin, and polymyxin B (44%), or oxytetracycline and polymyxin B (21%). Polymyxin B was present in all cases. Vaccines or other drugs were also administered to 51% of cats. In 56% cases, anaphylaxis occurred within 10 min of drug application. Most (82%) cats survived. Although a causal association was not proved, ophthalmic antibiotic administration preceded anaphylaxis in all cats. Like other drugs, ophthalmic antibiotics should be used only when indicated.