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Plant-Based Adjunct Therapy for Tuberculosis
Published in Namrita Lall, Medicinal Plants for Cosmetics, Health and Diseases, 2022
Lydia Gibango, Anna-Mari Reid, Jonathan L. Seaman, Namrita Lall
Bacteria have the ability to adhere to each other and grow on almost any surface (biotic and abiotic). They form complex communities of microbial cells that are enclosed in an extracellular matrix composed of polysaccharide material (Donlan, 2002). First reports of the concept of biofilms date back to 1978 (Costerton et al., 1978). Biofilms are of significance to human health as they can form in natural, industrial and medical environments. More specifically, in a medical setting, biofilms can form on medical devices such as catheters or implants, which may result in chronic infections that are harder to treat (López et al., 2010). Biofilm infections are associated with resistance and/or tolerance to antimicrobial compounds and persist despite prolonged host defenses (Hall-Stoodley and Stoodley, 2009).
Bioengineering of Inorganic Nanoparticle Using Plant Materials to Fight Extensively Drug-Resistant Tuberculosis
Published in Richard L. K. Glover, Daniel Nyanganyura, Rofhiwa Bridget Mulaudzi, Maluta Steven Mufamadi, Green Synthesis in Nanomedicine and Human Health, 2021
Mpho Phehello Ngoepe, Maluta Steven Mufamadi
The treatment success varies between TB, MDR-TB and XDR-TB at 83%, 52% and 28%, respectively (Rahman and Sarkar, 2017). This shows that more work is required to improve treatment outcomes for XDR-TB. Treatment of biofilm-associated infections is a major challenge. The eradication of biofilm is challenging because the extracellular polymeric substances (EPS) comprising the biofilm (consisting of keto-mycolic acids) prevent the antibiotic penetration and host’s immune defences into biofilms (Eldholm and Balloux, 2016). Thus, biofilm formation by pathogens appears to facilitate the survival of these pathogens in the environment and the host. Current methods to eradicate biofilms typically require excising of infected tissues combined with antibiotic therapy, invasive treatments that incur high medical costs (Wang et al., 2016a). Various agents have been designed to target the biofilm architecture, disperse the microbial cells into their more vulnerable, planktonic mode of life. These dispersing agents vary enzymes (proteases, deoxyribonucleases and glycoside hydrolases), antibiofilm peptides (human cathelicidin, LL-37) and dispersal molecules such as dispersal signals (cis-2-decanoic acid – CDA, nitric oxide), anti-matrix molecules (chitosan, d-amino acids, urea) and sequestration molecules (lactoferrin, EDTA) (Fleming and Rumbaugh, 2017). Although various penetrating agents can be conjugated to antibiotics or biocides, they can be enzymatically inactivated in biofilms.
Complications of Fillers and Their Management
Published in Neil S. Sadick, Illustrated Manual of Injectable Fillers, 2020
Biofilms are an aggregation of microorganisms that adhere to the surface of fillers. Patients present with pain, erythema, and induration to the injection site. In the case of biofilm, this presents weeks to months after injection. Prevention of biofilms requires good use of preprocedure cleansing and disinfection. Injections through oral mucosa are to be avoided; do not use a needle from lip to other sites. Treatment includes hyaluronidase in the case of HA fillers to remove the substrate. Cultures are to be taken whenever possible and treatment with appropriate oral antibiotics instituted. The use of 5-fluorouracil for biofilms has been reported as has surgical excision (70).
Design and assessment of novel synthetic peptides to inhibit quorum sensing-dependent biofilm formation in Pseudomonas aeruginosa
Published in Biofouling, 2022
Fatemeh Aflakian, Mehrnaz Rad, Gholamreza Hashemitabar, Milad Lagzian, Mohammad Ramezani
Inhibition of biofilm production is still one of the most important medical and veterinary problems and needs more investigations. In general, removing biofilms after formation is difficult and the best strategy is to prevent their formation. Interfering with QS of P. aeruginosa is a hopeful approach. The binding of auto-inducer molecules to LasR in the QS system increases biofilm production, resistance to antibiotics and virulence (O'Brien et al. 2015). Thus, targeting the binding domain of this protein could be a new therapeutic strategy (Chen et al. 2011). In this study, synthetic peptides with the effect of LasR protein antagonist were designed and synthesized for interference in the QS system. The peptides used in this study, with their significant anti-biofilm effects and low toxicity on eukaryotic cells, are potential candidates for inhibiting P. aeruginosa biofilm formation.
Nanomaterials as drug delivery systems with antibacterial properties: current trends and future priorities
Published in Expert Review of Anti-infective Therapy, 2021
Khatereh Khorsandi, Reza Hosseinzadeh, Homa Sadat Esfahani, Saeedeh Keyvani-Ghamsari, Saeed Ur Rahman
The formation of microbial biofilms is a major cause for the defeat of antimicrobial therapy. Many mechanisms are believed to participate in biofilm sensitivity and resistance. These mechanisms include; infiltration of the antimicrobial agent into the biofilm, alterations in the chemical microenvironment within the biofilm. One mechanism of biofilm resistance to antimicrobial agents is the failure of an agent to infiltration the entire depth of the biofilm. Uncommonly, antibiotics with positively charged can bind to the negatively charged molecules of the biofilm. This connection can hinder the passage of the antibiotic to the biofilm depth biofilm-associated infections expressed as one of the main intimidations of advanced medicine. Consequently, several inhibitory procedures such as mechanical, physical, and chemical methods can be used properly for controlling biofilm formation or destroy mature biofilm [229].
Synergistic antimicrobial combination of carvacrol and thymol impairs single and mixed-species biofilms of Candida albicans and Staphylococcus epidermidis
Published in Biofouling, 2020
Thirukannamangai Krishnan Swetha, Arumugam Vikraman, Chari Nithya, Nagaiah Hari Prasath, Shunmugiah Karutha Pandian
In clinical settings, microbial biofilms can cause persistent infections that resist conventional antibiotic therapy and promote resistance development (Costerton et al. 1987; Adam et al. 2002). Surface coating of medical devices can be valuable in preventing microbial adhesion and biofilm formation (Pan et al. 2018; Carinci et al. 2019). Thus, biofilm formation by mono-species and mixed-species on surfaces coated with C + T was evaluated. The C + T combination applied at 2× and 4× the ESCs significantly hampered the formation of mono- and mixed-species biofilms by inhibiting microbial growth. Since the C + T combination effectively kills and/or prevents adhesion and proliferation of the initially available planktonic cells, this synergistic combination might be potentially useful in preventing biofilm related implant infections. The observation that 1× the ESC was less effective, regardless of its proficient antimicrobial activity, could be attributed to the volatile nature of C and T. The simple evaporation technique used for surface coating in this study could have led to the loss of these compounds, which would reduce the effectiveness of the 1× the ESC of the C + T combination on microbial growth and biofilm formation. These disadvantages might be overcome by appropriate modification of the surface coating strategy.