Antimicrobial activity of essential oils against Pasteurella spp. isolated from the oral cavity of domestic cats

ABSTRACT: Pasteurella spp. have been identified predominantly in the oral microbiota of domestic cats. However, Pasteurella spp. was significantly more prevalent in cats with inflammatory oral disease; and consequently, it was considered as part of the etiology in this disease. In addition, in animals, Pasteurella spp. have become increasingly resistant to a large number of antimicrobials. Natural products, especially essential oils, could contribute to minimizing this issue. This study determined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of six essential oils against Pasteurella spp. isolates from the oral cavity of domestic cats. Our results showed that essential oils with better antimicrobial effectiveness against most of the Pasteurella isolates were lemongrass, tea tree and clove, with inhibition values between 50 to 800 µg mL-1. All essential oils showed bacteriostatic activity against the species of Pasteurella isolated from the domestic cats. These results suggested that lemongrass, tea tree and clove oils have potential to be used in products for oral hygiene and treatment of oral infections in domestic cats.

Liquid-Assisted Electrospinning Three-Dimensional Polyacrylonitrile Nanofiber Crosslinked with Chitosan

Electrospinning has become a popular nanotechnology for the fabrication of tissue engineering scaffolds, which can precisely regulate fiber diameter and microstructure. Herein, we have prepared a three-dimensional polyacrylonitrile (PAN) nanofiber by liquid-assisted electrospinning. The spacing between PAN nanofibers can reach to 15-20 μm, as the uniform internally connected pore structure can be formed, through the regulation of parameters. Furthermore, the chitosan attached to the as-prepared nanofibers gives the material antibacterial effect and increases its biocompatibility. Meanwhile, the special structure of chitosan also provides the possibility for further loading drugs in dressings in the future. This newly developed nanocomposite seems to be highly suitable for wound healing due to its unique properties of biodegradability, biocompatibility, and antimicrobial effectiveness.

Determination of Anti-Pseudomonal Activities of Cocoa (Theobroma cacao) Pod Husk using Time-Kill-Test and Agar-Well Diffusion Techniques

Aim: To determine the antimicrobial effectiveness of cocoa pod husk against P. aeruginosa. Study Design: An experimental research Place and Duration of Study: Department of Medical Microbiology, Olabisi Onabanjo University Teaching Hospital, Sagamu, Ogun State, Nigeria, between June 2015 and Sept. 2016. Materials and Methods: Seventy-seven (77) isolates of P. aeruginosa obtained from three (3) teaching hospitals were involved in this study. Cocoa pod husk was processed into crude extract and its effectiveness against the isolates of P. aeruginosa were examined using agar well diffusion, time-kill test techniques and Anova. Results: The percentage susceptibility of P. aeruginosa to Cocoa pod husk at 500 mg/mL and 250 mg/mL inhibited all the P. aeruginosa but only 14.29% were sensitive at a lower concentration of 31.25 mg/mL. Moreover, the comparison between the broth micro and macro dilution method of determining the MIC of cocoa pod husk against P. aeruginosa highlighted a significant decrease in the mean MIC value of the broth micro dilution method when compared with the broth macro dilution technique (T=13.519, P<0.05). The time kill test emphasized that P. aeruginosa was killed at a lower concentration of 62.5mg/ml at 150mins of introduction in to the Cocoa pod husk suspension. Conclusion: This study revealed that the Cocoa pod husk possesses antibacterial properties. An increase in the concentration of cocoa pod husk increased its antibacterial activity against Pseudomonas aeruginosa. Moreover, the broth micro dilution technique is sensitive for determining the anti-pseudomonal activity.

Pseudomonas synergizes with fluconazole against Candida during treatment of polymicrobial infection

Polymicrobial infections are challenging to treat because we don't fully understand how pathogens interact during infection and how these interactions affect drug efficacy. Candida albicans and Pseudomonas aeruginosa are opportunistic pathogens that can be found in similar sites of infection such as in burn wounds and most importantly in the lungs of CF and mechanically ventilated patients. C. albicans is particularly difficult to treat because of the paucity of antifungal agents, some of which lack fungicidal activity. In this study, we investigated the efficacy of anti-fungal treatment during C. albicans-P. aeruginosa co-culture in vitro and co-infection in the mucosal zebrafish infection model analogous to the lung. We find that P. aeruginosa enhances the activity of fluconazole (FLC), an anti-fungal drug that is fungistatic in vitro, to promote both clearance of C. albicans during co-infection in vivo and fungal killing in vitro. This synergy between FLC treatment and bacterial antagonism is partly due to iron piracy, as it is reduced upon iron supplementation and knockout of bacterial siderophores. Our work demonstrates that FLC has enhanced activity in clinically relevant contexts and highlights the need to understand antimicrobial effectiveness in the complex environment of the host with its associated microbial communities.

A Review on Face masks – Current Scenario and Future Aspect

Viruses and bacteria have posed a significant threat in various parts of the planet at various times. However, in 2020, the entire world was affected at the same time in such a way that it changed the very foundation of how we live, work, and interact with one another. Never before in history has the entire human race been so vulnerable at the same moment. The most economical preventive measures for most people all over the world during this period were sanitizers and face masks. Many different types of face masks have been fabricated keeping various factors like their antimicrobial effectiveness, reusability, eco-friendly method of manufacturing, cost-effectiveness and most importantly biodegradability. This paper gives an overview of those materials which are used in face masks which could be synthesized easily and affordably. The future perspective of the masks is also briefly discussed keeping the smart and sensor based devices on the rise, providing information for researchers looking for ways to synthesise face masks that would satisfy the needs of the circumstance.

Orthodontic materials with fluoride have an antimicrobial ability for the prevention of white spot lesions

Aim: Orthodontic brackets during their wear cause demineralization of enamel, which is the initial step in caries development. The prevention of such spots is crucial to ensure healthy teeth, but patients’ compliance is not the most optimal way. The aim of this study was to compare the antimicrobial properties of fluoride-containing orthodontic materials to the materials without additional fluoride. Materials and Methods: Antibacterial effectiveness of orthodontic materials with fluoride – Transbond Plus SEP Bonding agent, Transpond Plus Adhesive agent, Fuji I Band cement, Fuji Ortho LC Adhesive agent, Ortho Solo Bonding agent, and without antimicrobial substances – Transpond XT Bonding agent, Transbond XT Primer were tested with the inhibition on most common causes L. achidophilus (ATCC 4356) and S. mutans (ATCC 10449) and compared to negative control. Antimicrobial effectiveness of each material was measured with the agar diffusion method and expressed with the diameters of inhibition zones around the disk. Results: Materials containing fluoride showed more antimicrobial effectiveness compared to materials without fluoride or negative control (p&lt;0.001), respectively. Materials from the group with no antibacterial substances were not statistically different compared to the negative control (P&gt;0.05). Conclusion: Materials containing fluoride showed more significant antimicrobial effectiveness when compared to the materials without antimicrobial substance and thus might have the potential of antimicrobial properties in vivo.

In vitro testing of silver-containing spacer in periprosthetic infection management

Deep infection is a serious complication in endoprosthetic surgery. In correlation to the patient local or systemic compromising factors conservative and surgical proceedings has to be evaluated. Systemic antibiotic therapy is the gold standard in infection management. Implanted silver-coated or silver-containing medical devices have been proven to their antimicrobial effectiveness since the 1990s by several investigators. The outcomes showed that long time implantation could cause damaging of the surrounding tissues, especially of adjacent nerves. The aim of our study was to evaluate the release of silver (I) ions from bone cement mixed with either nanosilver particles (AgNPs), different concentrations of silver sulfate (Ag2SO4) or from pure metallic silver strips. Therefore, we choose two methods: the first, called “static model”, was chosen to evaluate the maximal accumulative concentration of silver (I) ions, with the second, called “dynamic model”, we simulated a continuous reduction of the ions. In an additional test design, the different materials were evaluated for their antimicrobial activity using an agar gel diffusion assay. The outcome showed that neither the addition of 1% (w/w) nanosilver nor 0.1% silver sulfate (w/w) to polymethylmethacrylat bone cement has the ability to release silver (I) ions in a bactericidal/antifungal concentration. However, the results also showed that the addition of 0.5% (w/w) and 1% (w/w) silver sulfate (Ag2SO4) to bone cement is an effective amount of silver for use as a temporary spacer.