Research Support, Non-U.S. Gov'ts
- Isolation of Quinolone-Resistant Escherichia coli Found in Major Rivers in Korea
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Dahye Jung , Min Young Lee , Jung Min Kim , Je Chul Lee , Dong Taek Cho , Yeonhee Lee
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J. Microbiol. 2006;44(6):680-684.
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DOI: https://doi.org/2456 [pii]
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Abstract
- Twenty isolates resistant to seven quinolones were isolated from major rivers in Korea. All isolates had three mutations, Ser83→Leu and Asp87→Asn in GyrA and Ser80→Ile or Ser80→Arg in ParC and three isolates had an additional mutation Glu84→Gly or Glu84→Val in ParC. In addition, a clonal spread was not found in these isolates.
- Fluoroquinolone Resistance and gyrA and parC Mutations of Escherichia coli Isolated from Chicken
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Young-Ju Lee , Jae-Keun Cho , Ki-Seuk Kim , Ryun-Bin Tak , Ae-Ran Kim , Jong-Wan Kim , Suk-Kyoung Im , Byoung-Han Kim
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J. Microbiol. 2005;43(5):391-397.
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DOI: https://doi.org/2285 [pii]
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Abstract
- Escherichia coli is a common inhabitant of the intestinal tracts of animals and humans. The intestines of animals also represent an ideal environment for the selection and transfer of antimicrobial resistance genes. The aim of this study was to investigate the resistance of E. coli isolated from chicken fecal samples to fluoroquinolones and to analyze the characterization of mutations in its gyrA and parC gene related resistance. One hundred and twenty-eight E. coil isolates showed a high resistance to ciprofloxacin (CIP; 60.2%), enrofloxacin (ENO; 73.4%) and norfloxacin (NOR; 60.2%). Missense mutation in gyrA was only found in the amino acid codons of Ser-83 or Asp-87. A high percentage of isolates (60.2%) showed mutations at both amino acid codons. Missense mutation in parC was found in the amino acid codon of Ser-80 or Glu-84, and seven isolates showed mutations at both amino acid codons. Isolates with a single mutation in gyrA showed minimal inhibitory concentrations (MIC) for CIP (≤0.5 to 0.75 ug/ml), ENO (1 to 4 ug/ml) and NOR (0.75 to 4 ug/ml). These MIC were level compared to isolates with two mutations, one in gyrA and one in parC, and three mutations, one in gyrA and two in parC (CIP, ≤0.5 to 3 ug/ml; ENO, 2 to 32< ug/ml; NOR, 1.5 to 6 ug/ml). However, the isolates with two mutation in gyrA regardless of whether there was a mutation in parC showed high MIC for the three fluoroquinolones (CIP, 0.75 to 32 ≤ug/ml; ENO, 3 to 32 ≤ug/ml; NOR, 3 to 32 ≤ug/ml ). Interestingly, although the E. coil used in this study was isolated from normal flora of chicken, not clinical specimens, a high percentage of isolates showed resistance to fluoroquinolones and possessed mutations at gyrA and parC associated with fluoroquinolone resistance.
- Laboratory Developed fluoroquinolone Resistant Escherichia coli Has a new Missense Mutation in QRDR of PartC
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Lee, Soon Deuk , Lee, Yeon Hee
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J. Microbiol. 1998;36(2):106-110.
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Abstract
- The fluoroquinolone resistance mechanism of four laboratory developed fluorquinolone resistant strains of Escherichia coli was studied. Fluoroquinolone concentrations inside the resistant cells were similar to the concentrations in the susceptible cells. DNA sequencing of the quinolone resistance determining regions (QRDR) in gyrA and parC revealed the presence of Ser 83Leu and Asp87Gly mutations in GyrA, and Gly78Cys and Ser80Arh mutations in ParC of the ofloxacin, norfloxacin, and HK3140 resistant strains, while the ciprofloxacin resistant strain had Ser83Leu and Aasp87Tyr mutations in GyrA, and Gly78Cys and Ser80Ile mutations in ParC. A Gly78Cys substitution in ParC was newly detected in this work and seemed to be responsible for the extremely high MICs to fluroquinolones.