Antibiotic Susceptibility Profiles of Lactic Acid Bacteria from the Human Vagina and Genetic Basis of Acquired Resistances

• Published in: International journal of molecular sciences Vol. 21; no. 7; p. 2594
• Main Authors: Sirichoat, Auttawit, Flórez, Ana Belén, Vázquez, Lucía, Buppasiri, Pranom, Panya, Marutpong, Lulitanond, Viraphong, Mayo, Baltasar
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 08.04.2020; MDPI
• Subjects: Amino acid substitution; Amino acids; Ampicillin; Anti-Bacterial Agents - pharmacology; Antibiotic resistance; Antibiotics; Bacteria; Bifidobacterium bifidum - drug effects; Bifidobacterium bifidum - genetics; Bifidobacterium bifidum - physiology; Chloramphenicol; Chloromycetin; Deoxyribonucleic acid; DNA; Drug resistance; Drug Resistance, Bacterial - genetics; Ecosystems; Enzymes; Female; Food; Genes; genome analysis; Genomes; Gentamicin; Guanines; Humans; Insertion; Kanamycin; Lactic acid; Lactic acid bacteria; Lactobacillales - drug effects; Lactobacillales - genetics; Lactobacillales - physiology; Lactobacilli; Lactobacillus; Lactobacillus - drug effects; Lactobacillus - genetics; Lactobacillus - physiology; Microbiota; Minimum inhibitory concentration; Mutation; Pathogens; Polymorphism, Genetic; Probiotics; Proteins; Ribosomal protein S12; Strains (organisms); Streptomycin; Tetracycline - pharmacology; tetracycline resistance; Vagina; Vagina - microbiology; vaginal microbiota; Veterinary medicine; vaginal microbiota; antibiotic resistance; genome analysis; tetracycline resistance; Bifidobacterium bifidum; lactic acid bacteria; Lactobacillus
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms21072594

Lactic acid bacteria can act as reservoirs of antibiotic resistance genes that can be ultimately transferred to pathogens. The present work reports on the minimum inhibitory concentration (MIC) of 16 antibiotics to 25 LAB isolates of five and one species from the human vagina. Acquired resistances were detected to kanamycin, streptomycin, chloramphenicol, gentamicin, and ampicillin. A PCR analysis of lactobacilli failed to identify genetic determinants involved in any of these resistances. Surprisingly, a (W) gene was detected by PCR in two strains, although they proved to be tetracycline-susceptible. In agreement with the PCR results, no acquired genes were identified in the genome of any of the spp. strains sequenced. A genome analysis of VA07-1AN showed an insertion of two guanines in the middle of (W) interrupting the open reading frame. By growing the strain in the presence of tetracycline, stable tetracycline-resistant variants were obtained. An amino acid substitution in the ribosomal protein S12 (K43R) was further identified as the most likely cause of VA07-1AN being streptomycin resistance. The results of this work expand our knowledge of the resistance profiles of vaginal LAB and provide evidence for the genetic basis of some acquired resistances.