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
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Mentions: The first striking result of these analyses is the observation of a notable frequency of TRAs to all three antibiotics across most environments (fig. 1A). Rifamycin TRAs are segregated at the lowest frequencies. The frequency of RpoB sequences carrying a rifamycin TRA is on average 0.49% across environments and ranges between 0% and 1.70% for the different environments analyzed (fig. 1A). RpsL sequences carry resistance alleles to streptomycin with an average frequency of 7.44% across studied environments, ranging between 0% and 15.10% (fig. 1A). Across all environments sampled, resistance to streptomycin was conferred almost exclusively by a single resistance allele, arginine at RpsL position 88 (88R, position numbers are given in reference to the E. coli amino acid sequence, fig. 2). Quinolone TRAs segregate at the highest frequencies, with an average frequency across environments of 17.78%, ranging between 2.12% and 68.87% (fig. 1A).Fig. 1.—
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.