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- REVIEW] The Linkage between Reverse Gyrase and Hyperthermophiles: A Review of Their Invariable Association
- Michelle Heine , Sathees B.C. Chandra
- J. Microbiol. 2009;47(3):229-234. Published online June 26, 2009
- DOI: https://doi.org/10.1007/s12275-009-0019-8
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- 33 Citations
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Abstract
- With the discovery of reverse gyrase in 1972, from Yellowstone National Park, isolated from Sulfolobus acidocaldarius, it has been speculated as to why reverse gyrase can be found in all hyperthermophiles and just what exactly its role is in hyperthermophilic organisms. Hyperthermophiles have been defined as organisms with an optimal growth temperature of above 85°C. Reverse gyrase is responsible for the introduction of positive supercoils into closed circular DNA. This review of reverse gyrase in hyperthermophilic microorganisms summarizes the last two decades of research performed on hyperthermophiles and reverse gyrase in an effort to provide an up to date synopsis of their invariable association. From the data gathered for this review it is reasonable to hypothesize that reverse gyrase is closely tied to hyperthermophilic life.
Research Support, Non-U.S. Gov'ts
- Mutations in the GyrA Subunit of DNA Gyrase and the ParC Subunit of Topoisomerase IV in Clinical Strains of Fluoroquinolone-Resistant Shigella in Anhui, China
- Li-Fen Hu , Jia-Bin Li , Ying Ye , Xu Li
- J. Microbiol. 2007;45(2):168-170.
- DOI: https://doi.org/2517 [pii]
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Abstract
- In this research 26 Shigella isolates were examined by PCR and direct nucleotide sequencing for genetic alterations in the quinolone-resistance determining regions (QRDRs). We tested for the presence of qnr genes by PCR in 91 strains, but no qnr genes were found. The results did show, however, some novel mutations at codon 83 of gyrA (Ser→Ile) and codon 64 of parC (Ala64→Cys, Ala64→Asp), which were related to fluroquinolone resistance.
- Fluoroquinolone Resistance and gyrA and parC Mutations of Escherichia coli Isolated from Chicken
- Young-Ju Lee , Jae-Keun Cho , Ki-Seuk Kim , Ryun-Bin Tak , Ae-Ran Kim , Jong-Wan Kim , Suk-Kyoung Im , Byoung-Han Kim
- J. Microbiol. 2005;43(5):391-397.
- 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
- Lee, Soon Deuk , Lee, Yeon Hee
- 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.
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