A novel probiotic strain, Lactiplantibacillus plantarum LC38, isolated from Tunisian camel milk promoting wound healing in Wistar diabetic rats

Antimicrobial and probiotic properties were sought in Tunisian raw camel milk. One hundred and forty strains were isolated for this purpose. Initially, a screening based on growth kinetics under gastrointestinal tract (GIT) conditions allowed us to select only one strain that showed good resistance to pH 3 and 5% bovine bile. This isolate named LC38 was assayed for its autoaggregation capacity, surface hydrophobicity, antibiotic sensitivity, haemolytic and antimicrobial activities. The findings revealed strain LC38 sensitivity to several antibiotics, no haemolytic activity and antimicrobial activities against six pathogenic bacteria with an inhibition diameter that varies between 28 and 43 mm. Furthermore, this study revealed that this strain had good autoaggregation characteristics after 18 h of incubation and a high surface hydrophobicity that enhanced its adhesion ability to epithelial cells and for biofilm formation. Strain LC38 was submitted to classical identification with API50CH and to 16S rRNA gene sequencing, which revealed that the strain could be allocated to Lactiplantibacillus plantarum. Analysis of the structural composition of strain LC38 by high-performance liquid chromatography (HPLC) and Fourier transform-infrared (FTIR) spectroscopy analysis showed that probiotic suspension contains organic acids (lactic acid, succinic acid and citric acids). The application of Lactiplantibacillus plantarum LC38 on wound site in a diabetic rat model enhanced significantly wound healing activity and accelerated the wound closure after 14 days of wound induction. Altogether, these results demonstrated that LC38 isolate from camel milk has a number of promising properties that make it a prominent candidate with strong wound healing potential presumably achieved through its antimicrobial activities.