title: Antimicrobial susceptibility of Lactobacillus rhamnosus.
abstract: We aimed to determine the minimum inhibitory concentrations (MICs) of Lactobacillus rhamnosus (n=75) strains, to study their antibiotic resistance genes with microarray, and to assess the microbiological cut-off values of tested antimicrobial agents. L. rhamnosus strains were tested with agar dilution, broth microdilution and Etest methods for ampicillin, clindamycin, erythromycin, gentamicin, streptomycin, and tetracycline using specific LSM medium. Most of the L. rhamnosus strains were found phenotypically susceptible to all six antibiotics tested. Four of the strains were phenotypically multiresistant, three strains to clindamycin, erythromycin and streptomycin and one strain to streptomycin and tetracycline. Some of the resistant (n=8) and susceptible (n=5) strains were further studied with a microarray method to reveal the antibiotic resistance genes behind the phenotypic resistances. From our experience, we recommend that microbiological cut-off values should be proposed according to the method used.
authors.affiliation: Department of Biosciences, Nutrition and Food Biotechnology, University of Kuopio, Finland. jenni.korhonen@uku.fi
authors.forename: J M
authors.initials: JM
authors.lastname: Korhonen
authors.forename: A H A M
authors.initials: AH
authors.lastname: Van Hoek
authors.forename: M
authors.initials: M
authors.lastname: Saarela
authors.forename: G
authors.initials: G
authors.lastname: Huys
authors.forename: L
authors.initials: L
authors.lastname: Tosi
authors.forename: S
authors.initials: S
authors.lastname: Mayrhofer
authors.forename: A Von
authors.initials: AV
authors.lastname: Wright
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D024881:Drug Resistance, Bacterial; D052201:Lacticaseibacillus rhamnosus / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D008826:Microbial Sensitivity Tests
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins