Antibiotic resistance profile and adhesion properties of Lactobacillus crispatus M247

Abstract

In an attempt to better characterize the strain M247, a strain of Lactobacillus crispatus isolated in 1989 from the faeces of a healthy newborn baby, we have further investigated its antibiotic resistance profile, evaluating also antibiotics not recommended by the EFSA, and analyzing in addition its viability in the presence of a high concentration of boric acid, a molecule commonly use to eradicate antimycotic-resistant fungi from the vagina. At the same time, we have evaluated the ability of M247 to adhere to vaginal epithelial cells to get a better understanding of its vaginal colonizing properties. According to the obtained results, M247 appears to be insensitive to metronidazole, sulfamethoxazole and boric acid. Such resistance is not transferrable due to the total absence of mobile elements inside its genome. Moreover, the M247 strain has been shown to adhere by more than 70% to vaginal epithelial cells, thereby providing a mechanistic explanation of its vaginal colonizing capabilities observed both after local and oral use.