Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/4/2016
Publication Date: 6/16/2016
Citation: Whitehead, T.R. 2016. Robinsoniella peoriensis: A model anaerobic commensal bacterium for acquisition of antibiotic resistance? [abstract]. American Society for Microbiology.
Technical Abstract: Background: R. peoriensis was characterized in our laboratories from swine manure and feces as a Gram-positive, anaerobic bacterium. Since then strains of this species have been identified from a variety of mammalian and other gastrointestinal (GI) tracts, suggesting it is a member of the commensal microflora. R. peoriensis has also been isolated from human infections. Recently our laboratory isolated new antibiotic resistant (AR) R. peoriensis strains. Therefore it is of interest to determine the AR profiles of R. peoriensis strains from different ecosystems and locations worldwide. Methods: R. peoriensis strains were collected from the U.S., France, Sweden and Germany. Sources included human wounds, turtle feces, and mouse GI tract. AR profiles were determined using agar plate disc-diffusion technique. Strains were plated onto brain-heart infucion (BHI) agar and antibiotics (10 µg) were added to blank discs. The plates were then transferred to an anaerobic glovebox for growth at 37°C and observed for resistance. Strains resistant to antibiotics were subjected to polymerase chain reaction (PCR) analyses to determine the presence of resistance genes. Results: All strains of R. peoriensis shared resistance to ampicillin, gentamycin, kanamycin, and nalidixic acid were sensitive to vancomycin and fusidic acid. Variation in resistance was observed with tetracycline, erythromycin, and tylosin. The type strain, PPC31, another swine strain and a strain from turtle feces were found to be sensitive to all three antibiotics. One Swedish strain from a wound infection was also sensitive to the three antibiotics, whereas a second strain from human blood was resistant to tetracycline only. A strain from a French neonate was resistant to erythromycin/tylosin but not tetracycline. Initial studies indicate at least several of the strains are resistant to ciprofloxacin. PCR analyses indicated the presence of the tet(L) gene in at least one strain. Conclusions: All strains of R. peoriensis shared similar profiles to certain antibiotics, but the presence and absence of resistance to tetracycline and erythromycin suggests that strains may have acquired resistance genes, as indicated by the presence of tet(L). Strains may serve as models for testing for movement of resistance genes from other commensal and pathogenic bacteria. Further analyses of resistance genes in strains may provide insight into movement of resistance genes in the GI tract of various animals.