Alarmingly High Segregation Frequencies of Quinolone Resistance Alleles within Human and Animal Microbiomes Are Not Explained by Direct Clinical Antibiotic Exposure.
Bottom Line: Within host-associated environments, resistance to quinolones was most often conferred by a specific resistance allele.High frequencies of quinolone resistance alleles were also found within hosts that were not directly treated with antibiotics.Therefore, the high segregation frequency of quinolone resistance alleles occurring within the housekeeping targets of antibiotics in host-associated environments does not seem to be the sole result of clinical antibiotic usage.
Affiliation: Rachel & Menachem Mendelovitch Evolutionary Processes of Mutation & Natural Selection Research Laboratory, Department of Genetics and Developmental Biology, the Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.Show MeSH
Mentions: Next, for each of the five most frequent phyla, we examined how quinolone TRA frequency varied across the different environments examined (fig. 4). For these analyses, we only considered a given phylum in a given environment if we could find at least ten GyrA/ParC sequences belonging to that phylum in that environment. We found that for the three phyla that carry quinolone TRAs most frequently (Fusobacteria, Bacteroidetes, and Firmicutes), quinolone TRA frequency tended to be much higher within hosts. Resistance within these phyla is conferred almost exclusively by the 87/84G allele (fig. 4). In contrast for the two phyla that were less frequently found to carry TRAs (Actinobacteria and Proteobacteria), the difference between host-associated and non host-associated environments was far less clear (fig. 4).Fig. 4.—
Affiliation: Rachel & Menachem Mendelovitch Evolutionary Processes of Mutation & Natural Selection Research Laboratory, Department of Genetics and Developmental Biology, the Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.