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Diverse phenotypic and genotypic characterization among clinical Klebsiella pneumoniae and Escherichia coli isolates carrying plasmid-mediated quinolone resistance determinants.
Microb Drug Resist. 2011 Sep; 17(3):363-7.MD

Abstract

A total of 59 and 74 nonduplicate plasmid-mediated quinolone resistance (PMQR) genes-carrying Klebsiella pneumoniae and Escherichia coli isolates were collected. All strains were assayed for fluoroquinolone susceptibility and the prevalence of quinolone resistance-determining regions (QRDRs) mutation. The association between PMQR determinants and common β-lactamase genes was also analyzed. Genetic relatedness of the isolates was analyzed by pulsed-field gel electrophoresis (PFGE). The PMQR genes-carrying K. pneumoniae and E. coli isolates exhibited high fluoroquinolone resistance rates, indicating that PMQR determinants play an essential role in the development of fluoroquinolone resistance. Remarkably, most qnr-carrying strains had only a single or no QRDR mutation in GyrA or ParC, and most exhibited decreased ciprofloxacin (CIP) susceptibility or low-level CIP resistance. However, 71.4% and 98.4% of qnr-negative K. pneumoniae and E. coli contained double QRDR mutations, and most presented high-level CIP resistance. Additionally, K. pneumoniae presented a lower CIP resistance rate than E. coli (59.3% vs. 91.9%) and low carriage of double QRDR mutations (38.9% vs. 89.9%). Also, most (88.1%) K. pneumoniae examined in this study carried qnr and only 14.9% of E. coli were qnr positive. Thus, the high fluoroquinolone susceptibility of K. pneumoniae isolates is primarily due to fewer QRDR substitutions as a result of high prevalence of qnr alleles in the host. Our findings support the hypothesis that chromosomal resistance mutations could be affected by the presence of Qnr, in other words, Qnr may protect the QRDR domains in the gyrase and topoisomerase IV from mutations under the inhibition of fluoroquinolones. Another remarkable finding was that the PMQR genes-carrying K. pneumoniae exhibited much higher proportions of extended-spectrum β-lactamases (ESBLs)-positive phenotype than E. coli (73.5% vs. 59.5%). This is due to not only the high prevalence of SHV-type ESBL-conferring enzymes in K. pneumoniae but also the interference of DHA-producing K. pneumoniae as a result of the strong association between qnrB and bla(DHA).

Authors+Show Affiliations

Department of Microbiology, Chinese PLA General Hospital, Beijing, China.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

21563956

Citation

Yang, Jiyong, et al. "Diverse Phenotypic and Genotypic Characterization Among Clinical Klebsiella Pneumoniae and Escherichia Coli Isolates Carrying Plasmid-mediated Quinolone Resistance Determinants." Microbial Drug Resistance (Larchmont, N.Y.), vol. 17, no. 3, 2011, pp. 363-7.
Yang J, Luo Y, Cui S, et al. Diverse phenotypic and genotypic characterization among clinical Klebsiella pneumoniae and Escherichia coli isolates carrying plasmid-mediated quinolone resistance determinants. Microb Drug Resist. 2011;17(3):363-7.
Yang, J., Luo, Y., Cui, S., Wang, W., & Han, L. (2011). Diverse phenotypic and genotypic characterization among clinical Klebsiella pneumoniae and Escherichia coli isolates carrying plasmid-mediated quinolone resistance determinants. Microbial Drug Resistance (Larchmont, N.Y.), 17(3), 363-7. https://doi.org/10.1089/mdr.2011.0034
Yang J, et al. Diverse Phenotypic and Genotypic Characterization Among Clinical Klebsiella Pneumoniae and Escherichia Coli Isolates Carrying Plasmid-mediated Quinolone Resistance Determinants. Microb Drug Resist. 2011;17(3):363-7. PubMed PMID: 21563956.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Diverse phenotypic and genotypic characterization among clinical Klebsiella pneumoniae and Escherichia coli isolates carrying plasmid-mediated quinolone resistance determinants. AU - Yang,Jiyong, AU - Luo,Yanping, AU - Cui,Shenghui, AU - Wang,Weiwei, AU - Han,Li, Y1 - 2011/05/12/ PY - 2011/5/14/entrez PY - 2011/5/14/pubmed PY - 2012/3/1/medline SP - 363 EP - 7 JF - Microbial drug resistance (Larchmont, N.Y.) JO - Microb Drug Resist VL - 17 IS - 3 N2 - A total of 59 and 74 nonduplicate plasmid-mediated quinolone resistance (PMQR) genes-carrying Klebsiella pneumoniae and Escherichia coli isolates were collected. All strains were assayed for fluoroquinolone susceptibility and the prevalence of quinolone resistance-determining regions (QRDRs) mutation. The association between PMQR determinants and common β-lactamase genes was also analyzed. Genetic relatedness of the isolates was analyzed by pulsed-field gel electrophoresis (PFGE). The PMQR genes-carrying K. pneumoniae and E. coli isolates exhibited high fluoroquinolone resistance rates, indicating that PMQR determinants play an essential role in the development of fluoroquinolone resistance. Remarkably, most qnr-carrying strains had only a single or no QRDR mutation in GyrA or ParC, and most exhibited decreased ciprofloxacin (CIP) susceptibility or low-level CIP resistance. However, 71.4% and 98.4% of qnr-negative K. pneumoniae and E. coli contained double QRDR mutations, and most presented high-level CIP resistance. Additionally, K. pneumoniae presented a lower CIP resistance rate than E. coli (59.3% vs. 91.9%) and low carriage of double QRDR mutations (38.9% vs. 89.9%). Also, most (88.1%) K. pneumoniae examined in this study carried qnr and only 14.9% of E. coli were qnr positive. Thus, the high fluoroquinolone susceptibility of K. pneumoniae isolates is primarily due to fewer QRDR substitutions as a result of high prevalence of qnr alleles in the host. Our findings support the hypothesis that chromosomal resistance mutations could be affected by the presence of Qnr, in other words, Qnr may protect the QRDR domains in the gyrase and topoisomerase IV from mutations under the inhibition of fluoroquinolones. Another remarkable finding was that the PMQR genes-carrying K. pneumoniae exhibited much higher proportions of extended-spectrum β-lactamases (ESBLs)-positive phenotype than E. coli (73.5% vs. 59.5%). This is due to not only the high prevalence of SHV-type ESBL-conferring enzymes in K. pneumoniae but also the interference of DHA-producing K. pneumoniae as a result of the strong association between qnrB and bla(DHA). SN - 1931-8448 UR - https://www.unboundmedicine.com/medline/citation/21563956/Diverse_phenotypic_and_genotypic_characterization_among_clinical_Klebsiella_pneumoniae_and_Escherichia_coli_isolates_carrying_plasmid_mediated_quinolone_resistance_determinants_ L2 - https://www.liebertpub.com/doi/10.1089/mdr.2011.0034?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -