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Alarmingly High Segregation Frequencies of Quinolone Resistance Alleles within Human and Animal Microbiomes Are Not Explained by Direct Clinical Antibiotic Exposure.

Field W, Hershberg R - Genome Biol Evol (2015)

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.

View Article: PubMed Central - PubMed

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.

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Average segregation frequencies of TRAs to three antibiotic classes among bacteria residing within nine sampled environment types. (TRAs are defined as resistance alleles occurring within the housekeeping targets of antibiotics.) For each environment type, the average resistance allele frequency across all samples is depicted. Error bars represent standard deviations. (A) Frequency of TRAs to three broad-spectrum antibiotic classes: quinolones (green, TRAs found in the gyrA or parC genes), rifamycins (red, TRAs found in the rpoB gene), and streptomycin (blue, TRAs found in the rpsL gene). (B) Frequency of quinolone TRAs broken down by position within the GyrA/ParC protein sequences. Proportion of sequences carrying a quinolone TRA at any position is given in gray. Proportion of sequences carrying a quinolone TRA at position 83 of GyrA or 80 of ParC is given in red. Proportion of sequences carrying a quinolone TRA at position 87 of GyrA or 84 of ParC is given in blue.
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evv102-F1: Average segregation frequencies of TRAs to three antibiotic classes among bacteria residing within nine sampled environment types. (TRAs are defined as resistance alleles occurring within the housekeeping targets of antibiotics.) For each environment type, the average resistance allele frequency across all samples is depicted. Error bars represent standard deviations. (A) Frequency of TRAs to three broad-spectrum antibiotic classes: quinolones (green, TRAs found in the gyrA or parC genes), rifamycins (red, TRAs found in the rpoB gene), and streptomycin (blue, TRAs found in the rpsL gene). (B) Frequency of quinolone TRAs broken down by position within the GyrA/ParC protein sequences. Proportion of sequences carrying a quinolone TRA at any position is given in gray. Proportion of sequences carrying a quinolone TRA at position 83 of GyrA or 80 of ParC is given in red. Proportion of sequences carrying a quinolone TRA at position 87 of GyrA or 84 of ParC is given in blue.

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.—


Alarmingly High Segregation Frequencies of Quinolone Resistance Alleles within Human and Animal Microbiomes Are Not Explained by Direct Clinical Antibiotic Exposure.

Field W, Hershberg R - Genome Biol Evol (2015)

Average segregation frequencies of TRAs to three antibiotic classes among bacteria residing within nine sampled environment types. (TRAs are defined as resistance alleles occurring within the housekeeping targets of antibiotics.) For each environment type, the average resistance allele frequency across all samples is depicted. Error bars represent standard deviations. (A) Frequency of TRAs to three broad-spectrum antibiotic classes: quinolones (green, TRAs found in the gyrA or parC genes), rifamycins (red, TRAs found in the rpoB gene), and streptomycin (blue, TRAs found in the rpsL gene). (B) Frequency of quinolone TRAs broken down by position within the GyrA/ParC protein sequences. Proportion of sequences carrying a quinolone TRA at any position is given in gray. Proportion of sequences carrying a quinolone TRA at position 83 of GyrA or 80 of ParC is given in red. Proportion of sequences carrying a quinolone TRA at position 87 of GyrA or 84 of ParC is given in blue.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
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getmorefigures.php?uid=PMC4494058&req=5

evv102-F1: Average segregation frequencies of TRAs to three antibiotic classes among bacteria residing within nine sampled environment types. (TRAs are defined as resistance alleles occurring within the housekeeping targets of antibiotics.) For each environment type, the average resistance allele frequency across all samples is depicted. Error bars represent standard deviations. (A) Frequency of TRAs to three broad-spectrum antibiotic classes: quinolones (green, TRAs found in the gyrA or parC genes), rifamycins (red, TRAs found in the rpoB gene), and streptomycin (blue, TRAs found in the rpsL gene). (B) Frequency of quinolone TRAs broken down by position within the GyrA/ParC protein sequences. Proportion of sequences carrying a quinolone TRA at any position is given in gray. Proportion of sequences carrying a quinolone TRA at position 83 of GyrA or 80 of ParC is given in red. Proportion of sequences carrying a quinolone TRA at position 87 of GyrA or 84 of ParC is given in blue.
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.—

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.

View Article: PubMed Central - PubMed

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.

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