Development of Nanotechnology-Based Drug Delivery Systems for Controlling Clinical Multidrug-Resistant Staphylococcus aureus and Escherichia coli Associated with Aerobic Vaginitis

The growing prevalence of resistance to antibiotics potentially makes Escherichia coli and Staphylococcus aureus serious pathogens, necessitating the development of new antimicrobial agents. We extracted crude biosurfactants from a potential probiotic Bacillus spp. to control pathogenic bacteria associated with aerobic vaginal infection. Using nanotechnology formulations, we developed nanoemulsions based on biosurfactants at different concentrations (1% and 3.33%). The results showed that these nanoemulsions were stable, with a weighted index of 0.3, and demonstrated broad-spectrum antibacterial activity against Escherichia coli and Staphylococcus aureus, with MICs ranging between 1.25 and 4 mg/mL. Additionally, the nanoemulsions exhibited interesting antibiofilm effects. All strains became more sensitive to the antibiotics to which they were resistant because of various biosurfactant formulations combined with antibiotics. Lower concentrations of BNE1% and 3.33% were still more efficient than the crude biosurfactants. Our findings demonstrated that the biosurfactant had a strong antibiofilm effect against all tested pathogens. This antibacterial effect can be explained by their ability to alter cell physiology such as cell hydrophobicity and membrane disintegration. Thus, we can conclude that the use of nanotechnology formulations has improved this effect, and the nanoemulsions developed in this study can be used as a potential anti-infectious therapy against multidrug-resistant bacterial strains of clinical origin.

Biosurfactant production by Lactobacillus plantarum MGL-8 from mango waste

AIMS

Enhancing biosurfactant production from indigenous Lactobacillus plantarum MGL-8 using mango waste substrate, and evaluating its characteristics as food sanitiser.

METHODS AND RESULTS

Mango juice (a mixture of mango paste, sucrose, glycerol, and deionised water) was used for batch fermentation with L. plantarum MGL-8 (L-MJ) and uninoculated (MC-MJ). Agitation, aeration, and temperature were controlled. Maximum Lactic Acid Bacteria (LAB) growth was observed in MC-MJ and L-MJ at 48 h, and the L-MJ fermentation provided the highest biosurfactant yield of 4.22 g l^-1 at 120 h. The dried crude biosurfactant (BSF) provided surface tension 36.6 mN m^-1 , a maximum emulsification index (E24%) of 41% and zone of inhibition of 15.53 mm. Preliminary characterisation by Gas chromatography-Mass spectrometry (GC-MS) and Fourier transform infrared (FTIR) indicated a multi-component glycolipoprotein BSF associated with fatty dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, proteins, and polysaccharides. The BSF also displayed bactericidal activity against Listeria monocytogenes at 400 µg ml^-1 .

CONCLUSIONS

Mango waste substrate enhanced biosurfactant production by indigenous L. plantarum MGL-8.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study identifies a production process and characteristics of the biosurfactant, which can be employed as a food sanitiser.