Treatment of superficial pseudomonal infections with citric acid: an effective and economical approach

The efficacy and safety of acids as topical antimicrobial agents: a review

OBJECTIVE

Infected wounds, refractory to conventional therapy, are a major burden on the healthcare system. Available data show that many commonly used antiseptic agents may be toxic to the cells involved in the healing process and may affect the normal tissue repair. The topical use of different acids to control wound infections effectively and promote healing is well known. The present review aims to summarise the safety and efficacy of various acids as topical agents for treating wound infections.

METHOD

A literature search was performed in PubMed and manually from other sources (cross references and journal sites).

RESULTS

We reviewed 116 articles, from which data from 86 relevant articles were analysed. The studies showed that various organic acids were clinically effective in treating wound infections.

CONCLUSION

This study found that various organic acids can act as a substitute for antiseptics to control wound infections refractory to conventional antibiotic therapy and local wound care. Various organic acids differ in efficacy, safety and limitations as topical agents to control wound infections and promote healing. Some acids deliver better results than others, particularly in those cases in which antibiotics and routine antiseptic agents yield little lasting success, especially in controlling hospital strains with multiple antibiotic resistance. Among topically used acids, citric acid and acetic acid are associated with better results.

The Acid-Buffered Engineered Gel Promotes In Vitro Cutaneous Healing and Fights Resistant Bacteria in Wounds

Background: Treatment of cutaneous wound infections is becoming a major clinical challenge due to the growing problem of antimicrobial resistance associated with existing wound treatments. Two prevalent pathogens in wound infections, Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa), continue to present a serious challenge, underscoring the critical need for new therapeutic alternatives. Methods: Novel alginate acid-buffered gels (ABF-1, ABF-2, and ABF-3) were developed using a combination of organic acids in various concentrations and buffered at a pH of 4.5. The acid-buffering capacity of the gels was evaluated against sodium hydroxide solution and simulated wound fluid (SWF) at different wound pHs, mimicking infected and non-infected wound environments. The in vitro antibacterial activity was assessed against resistant bacterial strains (Gram-positive and Gram-negative) using a microdilution method and wound biofilm assay. The rheological properties and cell viability of the gels were evaluated and the gel showing positive cell viability was further investigated for healing ability using an in vitro wound scratch assay. Results: The gels showed promising in vitro antibacterial activity against Staphylococcus epidermidis, S. aureus, and P. aeruginosa. Gels with higher acid concentrations (ABF-1 and ABF-2) were highly effective in reducing the bacterial load in chronic biofilms of S. aureus and P. aeruginosa, while the gel with a lower acid concentration (ABF-3) showed positive effects on the viability of skin cells (over 80% cells viable) and for promoting wound closure. All three gels demonstrated excellent acid-buffering capabilities. Conclusions: The acid-buffered gels demonstrate promising in vitro antibacterial effects, indicating their potential for enhancing wound healing.

Attenuation of Pseudomonas aeruginosa Virulence by Pomegranate Peel Extract

Pseudomonas aeruginosa is an opportunistic pathogen often responsible for biofilm-associated infections. The high adhesion of bacterial cells onto biotic/abiotic surfaces is followed by production of an extracellular polysaccharidic matrix and formation of a sessile community (the biofilm) by the release of specific quorum-sensing molecules, named autoinducers (AI). When the concentrations of AI reach a threshold level, they induce the expression of many virulence genes, including those involved in biofilm formation, motility, pyoverdine and pyocyanin release. P. aeruginosa embedded into biofilm becomes resistant to both conventional drugs and the host's immune response. Accordingly, biofilm-associated infections are a major clinical problem underlining the need for new antimicrobial therapies. In this study, we evaluated the effects of pomegranate peel extract (PomeGr) in vitro on P. aeruginosa growth and biofilm formation; moreover, the release of four AI was assessed. The phenolic profile of PomeGr, exposed or not to bacteria, was determined by high-performance liquid chromatography coupled to electrospray ionization mass spectrometry (HPLC-ESI-MS) analysis. We found that bacterial growth, biofilm production and AI release were impaired upon PomeGr treatment. In addition, the PomeGr phenolic content was also markedly hampered following incubation with bacterial cells. In particular, punicalagin, punicalin, pedunculagin, granatin, di-(HHDP-galloyl-hexoside) pentoside and their isomers were highly consumed. Overall, these results provide novel insights on the ability of PomeGr to attenuate P. aeruginosa virulence; moreover, the AI impairment and the observed consumption of specific phenolic compounds may offer new tools in designing innovative therapeutic approaches against bacterial infections.

Phytochemical Characterization, Anti-Oxidant, Anti-Enzymatic and Cytotoxic Effects of Artemisia verlotiorum Lamotte Extracts: A New Source of Bioactive Agents

Artemisia verlotiorum Lamotte is recognized medicinally given its long-standing ethnopharmacological uses in different parts of the world. Nonetheless, the pharmacological properties of the leaves of the plant have been poorly studied by the scientific community. Hence, this study aimed to decipher the phytochemicals; quantify through HPLC-ESI-MS analysis the plant’s biosynthesis; and evaluate the antioxidant, anti-tyrosinase, amylase, glucosidase, cholinesterase, and cytotoxicity potential on normal (NIH 3T3) and human liver and human colon cancer (HepG2 and HT 29) cell lines of this plant species. The aqueous extract contained the highest content of phenolics and phenolic acid, methanol extracted the most flavonoid, and the most flavonol was extracted by ethyl acetate. The one-way ANOVA results demonstrated that all results obtained were statistically significant at p < 0.05. A total of 25 phytoconstituents were identified from the different extracts, with phenolic acids and flavonoids being the main metabolites. The highest antioxidant potential was recorded for the aqueous extract. The best anti-tyrosinase extract was the methanolic extract. The ethyl acetate extract of A. verlotiorum had the highest flavonol content and hence was most active against the cholinesterase enzymes. The ethyl acetate extract was the best α-glucosidase and α-amylase inhibitor. The samples of Artemisia verlotiorum Lamotte in both aqueous and methanolic extracts were found to be non-toxic after 48 h against NIH 3T3 cells. In HepG2 cells, the methanolic extract was nontoxic up to 125 µg/mL, and an IC50 value of 722.39 µg/mL was recorded. The IC50 value exhibited in methanolic extraction of A. verlotiorum was 792.91 µg/mL in HT29 cells. Methanolic extraction is capable of inducing cell cytotoxicity in human hepatocellular carcinoma without damaging normal cells. Hence, A. verlotiorum can be recommended for further evaluation of its phytochemical and medicinal properties.

Impact of Carbon Source Supplementations on Pseudomonas aeruginosa Physiology

Pseudomonas aeruginosa is an opportunistic pathogen highly resistant to a wide range of antimicrobial agents, making its infections very difficult to treat. Since microorganisms need to perpetually adapt to their surrounding environment, understanding the effect of carbon sources on P. aeruginosa physiology is therefore essential to avoid increasing drug-resistance and better fight this pathogen. By a global proteomic approach and phenotypic assays, we investigated the impact of various carbon source supplementations (glucose, glutamate, succinate, and citrate) on the physiology of the P. aeruginosa PA14 strain. A total of 581 proteins were identified as differentially expressed in the 4 conditions. Most of them were more abundant in citrate supplementation and were involved in virulence, motility, biofilm development, and antibiotic resistance. Phenotypic assays were performed to check these hypotheses. By coupling all this data, we highlight the importance of the environment in which the bacterium evolves on its metabolism, and thus the necessity to better understand the metabolic pathways implied in its adaptative response according to the nutrient availability.

Role of an acidic environment in the treatment of diabetic foot infections: A review

Management of diabetic foot ulcers is the biggest challenge to the clinician, as conventional antibiotic therapies and local wound care have their own limitations. They are not effective for control of infections and promotion of healing because of cytotoxic effects. In view of cytotoxicity of routinely used topical antiseptic agents, this article focuses on the search of an ideal topical antiseptic agent that is safe and effective in controlling infectious agents and also in promoting the healing process. This review focuses on the use of various acids such as citric, acetic, hyaluronic, and hypochlorous acids as topical agents in diabetic foot infections. This article also focuses on the different roles of acids in the treatment of diabetic foot infections.

Acetic acid dressings: Finding the Holy Grail for infected wound management

Background

Wounds have since long, contributed majorly to the health-care burden. Infected long-standing non-healing wounds place many demands on the treating surgeon and are devastating for the patients physically, nutritionally, vocationally, financially, psychologically and socially. Acetic acid has long been included among agents used in the treatment of infected wounds. In this study, we have evaluated the use of acetic acid for topical application in the treatment of infected wounds.

Materials and Methods

A total of 100 patients with infected wounds were treated with topical application of 1% acetic acid as dressing material after appropriate cleaning. A specimen of wound swab was collected before first application and further on days 3, 7, 10 and 14. Daily dressings of wounds were done similarly. Minimum inhibitory concentration (MIC) of acetic acid against various organisms isolated was determined.

Results

The patients treated ranged between 9 and 60 years, with the mean age 33 years. Nearly 70% of patients were male. Aetiologies of wounds: infective 35, diabetic 25, trauma 20, burns 10, venous ulcers 5 and infected graft donor site 5. Various microorganisms isolated include Pseudomonas aeruginosa (40%), Staphylococcus aureus (2%), Acinetobacter (12%), Escherichia Coli (5%), Proteus mirabilis (3%), Klebsiella (18%), methicillin-resistant S. aureus (10%), Streptococcus (2%) and Enterococcus (1%), Citrobacter (1%). Few wounds (6%) also isolated fungi. About 28%, 64% and 8% of patients isolated no growth on culture after 7, 14 and 21 days, respectively. MIC of all isolated organisms was ≤0.5%.

Conclusion

pH of the wound environment plays a pivotal role in wound healing. Acetic acid with concentration of 1% has shown to be efficacious against wide range of bacteria as well as fungi, simultaneously accelerating wound healing. Acetic acid is non-toxic, inexpensive, easily available and efficient topical agent for effective elimination of wound infections caused due to multi-drug resistant, large variety of bacteria and fungus.

Structure-Function Relationships of a Tertiary Amine-Based Polycarboxybetaine

Zwitterionic polycarboxybetaine (PCB) materials have attracted noticeable interest for biomedical applications, such as wound healing/tissue engineering, medical implants, and biosensors, due to their excellent antifouling properties and design flexibility. Antifouling materials with buffering capability are particularly useful for many biomedical applications. In this work, an integrated zwitterionic polymeric material, poly(2-((2-hydroxyethyl)(2-methacrylamidoethyl)ammonio)acetate) (PCBMAA-1T), was synthesized to carry desired properties (antifouling, switchability and buffering capability). A tertiary amine was used to replace quaternary ammonium as the cation to endow the materials with buffering capability under neutral pH. Through this study, a better understanding on the structure-property relationship of zwitterionic materials was obtained. The tertiary amine cation does not compromise antifouling properties of zwitterionic materials. The amount of adsorbed proteins on PCBMAA-1T polymer brushes is less than 0.8 ng/cm(2) for fibrinogen and 0.3 ng/cm(2) (detection limit of the surface plasmon resonance sensor) for both undiluted blood plasma and serum. It is found that the tertiary amine is favorable to obtain good lactone ring stability in switchable PCB materials. Titration study showed that PCBMAA-1T could resist pH changes under both acidic (pH 1-3) and neutral/basic (pH 7-9) conditions. To the best of our knowledge, such an all-in-one material has not been reported. We believe this material might be potentially used for a variety of applications, including tissue engineering, chronic wound healing and medical device coating.

Antimicrobial activity of ibuprofen: new perspectives on an "Old" non-antibiotic drug

Pharmaceutical industry has been encountering antimicrobial activity of non-antibiotics during suitability tests carried out prior to routine pharmacopoeial microbiological purity analysis of finished dosage forms. These properties are usually ignored or perceived as a nuisance during pharmaceutical analysis. The aim of this study was: (i) to compare the available data to our method suitability test results carried out on products containing ibuprofen, i.e. to demonstrate that method suitability can be a valuable tool in identifying new antimicrobials, (ii) to demonstrate the antimicrobial activity of ibuprofen and ibuprofen lysine. Microbiological purity method suitability testing was carried out according to European Pharmacopoeia (EP), chapters 2.6.12. and 2.6.13. Antimicrobial activity of ibuprofen and ibuprofen lysine was demonstrated by a disk diffusion method, a modification of the European Committee for Antimicrobial Susceptibility Testing method (EUCAST), against test microorganisms recommended in the EP. It was confirmed that ibuprofen may be responsible for the broad spectrum of antimicrobial activity of the tested products, and that method suitability tests according to the EP can indeed be exploited by the scientific community in setting guidelines towards future research of new antimicrobials. In the disk diffusion assay, inhibition zones were obtained with more than 62.5 μg and 250 μg for Staphylococcus aureus, 125 μg and 250 μg for Bacillus subtilis, 31.3 μg and 125 μg for Candidaalbicans, 31.3 μg and 62.5 μg for Aspergillusbrasiliensis, of ibuprofen/disk, and ibuprofen lysine/disk, respectively. For Escherichiacoli, Pseudomonasaeruginosa and Salmonellatyphimurium inhibition zones were not obtained. Antimicrobial activity of ibuprofen is considered merely as a side effect, and it is not mentioned in the patient information leaflets of ibuprofen drugs. As such, for the patient, it could represent an advantage, but, it could also introduce additional risks during usage. Further microbiological, pharmacological and clinical trials are of great importance.

Assessment of the effectiveness of silver-coated dressing, chlorhexidine acetate (0.5%), citric acid (3%), and silver sulfadiazine (1%) for topical antibacterial effects against the multi-drug resistant Pseudomonas aeruginosa infecting full-skin thickness burn wounds on rats

The aim of this study was to compare the effects of four different topical antimicrobial dressings on a multi-drug resistant Pseudomonas aeruginosa contaminated full-thickness burn wound rat model. A total of 40 adult male Wistar albino rats were used. The control group (group 1), silver sulfadiazine (1%) group 2, chlorhexidine acetate (0.5%) group 3, citric acid (3%) group 4, and silver-coated dressing group 5 were compared to assess the antibacterial effects of a daily application to a 30% full-skin thickness burn wound seeded 10 minutes earlier with 10(8) CFU (colony forming unit)/0.5 mL of a multi-drug resistant Pseudomonas aeruginosa strain. Five groups (1 control group and 4 treatment groups) were compared. The administration of third-degree burns to all rats was confirmed based on histopathologic data. The tissue cultures from groups 2 and 5 exhibited significant differences compared to those of the other 3 groups, whereas no significant differences were observed between groups 1, 3, and 4. The effectiveness of the treatments was as follows: 1% silver sulfadiazine > silver-coated dressing > 3% citric acid > 0.5% chlorhexidine acetate > control group. Our results supported the efficacy of topical therapy by silver sulfadiazine and silver-coated dressing on infections caused by multi-drug resistant Pseudomonas spp.

Acetic Acid, the active component of vinegar, is an effective tuberculocidal disinfectant

Effective and economical mycobactericidal disinfectants are needed to kill both Mycobacterium tuberculosis and non-M. tuberculosis mycobacteria. We found that acetic acid (vinegar) efficiently kills M. tuberculosis after 30 min of exposure to a 6% acetic acid solution. The activity is not due to pH alone, and propionic acid also appears to be bactericidal. M. bolletii and M. massiliense nontuberculous mycobacteria were more resistant, although a 30-min exposure to 10% acetic acid resulted in at least a 6-log10 reduction of viable bacteria. Acetic acid (vinegar) is an effective mycobactericidal disinfectant that should also be active against most other bacteria. These findings are consistent with and extend the results of studies performed in the early and mid-20th century on the disinfectant capacity of organic acids. IMPORTANCE Mycobacteria are best known for causing tuberculosis and leprosy, but infections with nontuberculous mycobacteria are an increasing problem after surgical or cosmetic procedures or in the lungs of cystic fibrosis and immunosuppressed patients. Killing mycobacteria is important because Mycobacterium tuberculosis strains can be multidrug resistant and therefore potentially fatal biohazards, and environmental mycobacteria must be thoroughly eliminated from surgical implements and respiratory equipment. Currently used mycobactericidal disinfectants can be toxic, unstable, and expensive. We fortuitously found that acetic acid kills mycobacteria and then showed that it is an effective mycobactericidal agent, even against the very resistant, clinically important Mycobacterium abscessus complex. Vinegar has been used for thousands of years as a common disinfectant, and if it can kill mycobacteria, the most disinfectant-resistant bacteria, it may prove to be a broadly effective, economical biocide with potential usefulness in health care settings and laboratories, especially in resource-poor countries.

Acetic acid treatment of pseudomonal wound infections--a review

PURPOSE

Pseudomonas aeruginosa is a significant cause of burn wound infections and, skin and soft tissue infections. The antiseptic management is an integral part of the management of wound infections and is essential to control wound infection. Although commonly used, concerns have been raised.

RESULTS

Available experimental data suggest that many commonly used antiseptic agents may be toxic to the cells involved in wound healing process and may affect the process of normal tissue repair. In view of this, the present review summarized the various organic acids commonly used as a substitute for antiseptics to control pseudomonal wound infections with special reference to acetic acid and their role in the process of wound healing.

CONCLUSION

Acetic acid is to be kept in mind as one of the alternatives when infection is caused by multiple antibiotic resistant strains of P. aeruginosa. At a time when bacterial resistance to antibiotics is a matter of increasing concern, the value of topical agents such as acetic acid should not be forgotten.

Treatment of lepromatous ulcers using citric acid as a sole antimicrobial agent

A prospective study was carried out to assess the role of citric acid as a sole antimicrobial agent in the management of lepromatous ulcers. Thirty-four known cases of lepromatous ulcers not responding to conventional antibiotic therapies for long duration were investigated for culture and susceptibility studies. Staphylococcus aureus (25·00%) and Klebsiella spp. (23·43%) were found to be the most common isolates. Amikacin (68·75%) and ciprofloxacin (67·18%) were found to be the most effective antimicrobial agents. Topical application of citric acid ointment resulted in complete healing in 25 (73·52%) cases. In eight cases (26·48%), there was elimination of infective agent from ulcer site and formation of healthy granulation, but no complete healing of ulcer was seen. Results indicate that citric acid is the best alternative for the effective management of lepromatous ulcers when other therapies are exhausted.

Citric acid treatment of postoperative wound in an operated case of synovial sarcoma of the knee

A 40-year-old female presented with history of swelling at the upper and middle of the left leg since 6 months was confirmed as post cancer surgery non healing wound not responding to conventional antibiotic therapy and local wound care in an operated case of synovial sarcoma of the knee, monophasic fibrous type with no lung metastasis. Post surgical non healing wound not responding to conventional therapy was treated successfully with local application of 3% citric acid ointment for 25 days.

Citric acid treatment of necrotizing fasciitis: a report of two cases

Necrotizing fasciitis is a destructive invasive infection of skin, subcutaneous tissue and deep fascia, with relative sparing of muscle. It is a life-threatening condition. Here we report two cases of necrotizing fasciitis, which were not responding to conventional antibiotic therapy and local wound care after aggressive debridement. These two cases were treated simply by local application of 3% citric acid. Thus, citric acid was used to compliment wound management following surgical treatment with antibiotics.

A simple and effective approach for the treatment of diabetic foot ulcers with different Wagner grades

Diabetic foot infections are the major cause of morbidity. Infection is the common sequel of diabetic foot ulceration that leads to delayed wound healing. These infections are difficult to control. If not addressed well in time, they may lead to amputation of foot. An attempt has been made to develop simple and effective treatment modality by using citric acid as a sole antimicrobial agent to control diabetic foot infections not responding to conventional treatment. Hundred and fifteen cases of diabetic foot ulcers of different Wagner grades infected with a variety of bacteria were investigated for culture and susceptibility, and susceptibility to citric acid. Citric acid gel was applied to ulcer to determine its efficacy in the management of diabetic foot ulcers with different Wagner grades. Citric acid gel was found effective in the control of foot infections; especially in Wagner grades I and II, the success rate was found to be more than 94%. In Wagner grade III also, it was found effective in complete healing of ulcers without deep osteomyelitis. Citric acid treatment is effective in the control of diabetic foot infections and in successful management of diabetic foot ulcers with Wagner grades I and II, and even with Wagner grade III, without deep osteomyelitis.

A simple and effective approach for the treatment of chronic wound infections caused by multiple antibiotic resistant Escherichia coli

Antimicrobial resistance is a major problem in present-day therapy. Despite the advent of newer antimicrobial agents with a broad spectrum of activity, multiple antibiotic resistant pathogens are difficult to eliminate from infected sites. The present study was carried out to develop an approach, using citric acid as a sole antimicrobial agent, for the treatment of chronic wound infections caused by multiresistant Escherichia coli (MAREC). A total of 34 cases of chronic wound infections yielding MAREC isolates on culture were studied. The antibacterial effect of citric acid against MAREC was evaluated in vitro by broth dilution method. Three percent citric acid gel was applied to each wound once daily until it healed completely. All 34 isolates were inhibited by citric acid with minimum inhibitory concentrations in the range of 1500-2000 microg/ml. Topical application of 3% citric acid to wounds 7-42 times resulted in elimination of MAREC from infected sites and successful healing of wounds in all 34 patients. This treatment modality was simple, reliable, non-toxic and effective. Hence, the use of citric acid for the cost-effective treatment of wound infections caused by MAREC is recommended.

Biofilm reduction by a new burn gel that targets nociception

AIMS

To compare the ability of an amorphous first aid topical gel containing vinegar, citric acid and EDTA (RescuDerm(TM); RESC) and various derivative formulations to eradicate Pseudomonas aeruginosa (PSEUD) and Staphylococcus epidermidis (STAPH) biofilms.

METHODS AND RESULTS

24-h biofilms prepared using the Minimum Biofilm Elimination Concentration (MBEC) Assay System were exposed for 4 or 24 h to the different gel formulations. Citric acid-free, acetic acid-free or acetic acid-free/sodium acetate-supplemented RESC gels reduced PSEUD and STAPH biofilm formation as effectively as RESC. Substituting the weak organic acids with equivalent concentrations of glacial acetic acid reduced the effectiveness of gel against PSEUD and STAPH biofilms by half, but viable bacterial counts still remained below 4 log(10) CFU/peg. Removal of gelling agent and/or EDTA enhanced efficacy against PSEUD but not STAPH biofilms. An acidified placebo gel formulation generated an only marginal bactericidal effect compared to that of RESC.

CONCLUSIONS

RESC is a promising new antimicrobial agent. Its weak organic acid content, rather than merely acidic pH, mediates its considerable in vitro bactericidal efficacy against bacterial biofilms.

SIGNIFICANCE AND IMPACT OF THE STUDY

These data, taken together with the observation that RescuDerm possesses broad in vitro bactericidal activity against other pathogen species, suggest the potential usefulness of this product for controlling biofilm formation on a variety of cutaneous traumatic and surgical wounds.