Plasmidmediated quinolone resistance pmqr was late in being discovered. Data concerning the prevalence of these determinants in upec in our hospital are quite limited. The dissemination of these genes in latin american countries, where the prescription of fluoroquinolones is high, has been described in several studies. Recently, a multiresistance plasmid was discovered that encodes transferable resistance to quinolones. Jacoby infectious disease department, lahey clinic, burlington, ma 01805 communicated by paul c. Moreover, three mechanisms for plasmidmediated quinolone resistance pmqr have been discovered since 1998 and include qnr proteins, the aminoglycoside acetyltransferase aac6. In plasmidcontaining strains no change in quinolone accumulation, outer membrane porins, or drug inactivation could be detected, implying a resistance mechanism different from those currently known. Pdf plasmidmediated quinolone resistance and lactamases in. To our knowledge, this is the first report of plasmidmediated quinolone resistance in s. The discovery in 1998 123 of qnr, a plasmidmediated horizontally transferable gene encoding quinolone resistance, has shed light on these phenomena. Plasmidmediated quinolone resistance in typhoidal salmonellae.
High incidence of plasmidmediated quinolone resistance. These genes, likely originating in aquatic organisms, code for pentapeptide repeat proteins. Although resistance was low in wildtype strains, higher levels of quinolone resistance arose readily by mutation. Plasmidmediated quinolone resistance determinant qnrs in. Prevalence of plasmidmediated quinolone resistance genes among ciprofloxacinnonsusceptible escherichia coli and klebsiella pneumoniae isolated from blood cultures in korea. The discovery in 1998 123 of qnr, a plasmidmediated hor. Development and evaluation of a multiplex pcr for eight plasmidmediated quinoloneresistance determinants. In the past, the recessive nature of resistant gyra alleles in merodiploids 187 was used to account for the lack of naturally occurring plasmidmediated quinolone resistance pmqr 48.
We have cloned the plasmidquinolone resistance gene, termed qnr, and found it in an integronlike. Chromosomal mutations and plasmidmediated quinolone resistance pmqr determinants have been implicated. Pdf mechanism of plasmidmediated quinolone resistance. Before the emergence of bacterial plasmidmediated quinolone resistance pmqr genes, research on the resistance mechanisms of fluoroquinolones were confined to mutations of chromosomal genes coding dna gyrase or topoisomerase iv in the quinolone resistance determining region qrdr hopkins et al. Unexpected occurrence of plasmidmediated quinolone. In a more recent study transferable plasmidmediated quinolone resistance associated with qnr was reported in quinoloneresistant clinical strains of e.
Plasmidmediated quinolone resistance determinants in quinolone. Prevalence of plasmidmediated quinolone resistance in norwegian and swedish clinical isolates of escherchia coli and klebsiella spp. Plasmidmediated quinolone resistance determinants in quinoloneresistant escherichia coli isolated from patients with bacteremia in. Ibcr, and plasmidmediated efflux pumps qepa and oqxab. Mechanism of plasmidmediated quinolone resistance pnas. Mechanisms prevalence of plasmidmediated quinolone resistance genes in clinical enterobacteria from argentina ezequiel albornoz,1 celeste lucero,1 genara romero,1 mar. Pdf plasmidmediated quinolone resistance in typhoidal. The plasmid mediated quinolone resistance genes qnra, qnrb, qnrs, qepa, and aac6. Although plasmidmediated quinolone resistance pmqr genes confer only a low level of resistance to. Unique features of aeromonas plasmid pac3 and expression. Here we report the cloning of qnr, the novel plasmidencoded quinolone resistance gene, the amplification and puri. Two copies of orf5, found in integrons in6 and in7, surround these genes.
The worldwide emergence of plasmidmediated quinolone resistance ari robicsek, george a jacoby, david c hooper fluoroquinolone resistance is emerging in gramnegative pathogens worldwide. Development and evaluation of a multiplex pcr for eight. Detection of chromosomal and plasmidmediated quinolone. We have cloned the plasmidquinolone resistance fication of qnr, its gene product. Six isolates were susceptible to nalidixic acid and presented reduced susceptibility to cipro. A preliminary report from south india article pdf available in indian journal of medical microbiology 321. Although plasmidmediated quinolone resistance pmqr was thought not to exist before its discovery in 1998, the past decade has seen an explosion of research characterizing this phenomenon. Plasmid genes qnra, qnrb, qnrc, qnrd, qnrs, and qnrvc code for proteins of the pentapeptide repeat family that protects dna gyrase and topoisomerase iv from quinolone inhibition. Plasmidmediated quinolone resistance among nontyphi. Investigation of six plasmidmediated quinolone resistance genes among clinical isolates of pseudomonas. Bacterial plasmidmediated quinolone resistance genes in aquatic. Bacterial plasmidmediated quinolone resistance genes in aquatic environments in china. Plasmidmediated quinolone resistance appears to be widely distributed, though it is still uncommon in nontyphi salmonella isolates from the united states, including strains that are quinolone susceptible by the criteria of the clinical and laboratory standards institute formerly the national committee for clinical laboratory standards.
Ibcrproducing escherichia coli peng wang,1 longfei hu,1 zhihui hao2 1agricultural biopharmaceutical laboratory, qingdao agricultural university, qingdao 266109, peoples republic of china. To assess the prevalence of plasmidmediated quinolone resistance using polymerase chain reaction pcr with qnr and mcbgspecific primers, jacoby et al. Ibcr and qepa genes was evaluated in a collection of 281 nalidixic acidresistant enterobacterial isolates recovered between september 2005 and december 2007 at the sahloul hospital, sousse, tunisia. Plasmidmediated quinolone resistance current knowledge. Prevalence of plasmidmediated quinolone resistance genes. Resistance to fluoroquinolones fq in uropathogenic escherichia coli upec has emerged as a growing problem. Pdf the animal reservoir of plasmidmediated quinolone resistance pmqr and. Contamination of soil and water with antibioticresistant bacteria may create reservoirs of antibiotic resistance genes that have the potential to negatively impact future public health through horizontal gene transfer. Palmatine is a plasmidmediated quinolone resistance pmqr inhibitor that restores the activity of ciprofloxacin against qnrs and aac6. Abstract the spread of antimicrobial resistance from human activity derived sources to natural habitats implicates wildlife as potential vectors of antimicrobial resistance transfer.
Prevalence of plasmidmediated quinolone resistance in. The plasmidmediated mechanisms provide only lowlevel resistance that by itself does not exceed the clinical breakpoint for susceptibility but nonetheless facilitates selection of higher level. The first plasmidmediated quinolone resistance gene, qnra1, was detected in 1998. No plasmidmediated quinolone resistance gene was detected in the isolates from seville. Plasmidmediated resistance has only recently been documented for the fluoroquinolones. Here we report the cloning of qnr, the novel plasmid tance plasmid was discovered that encodes transferable resistance encoded quinolone resistance gene, the amplification and puri to quinolones.
The increase in plasmidmediated quinolone resistance among nts isolated from humans in the united states. Resistance was soon observed and could also be readily selected in the laboratory. The plasmidmediated quinolone resistance pmqr genes have changed the resistance pattern to quinolones, especially among enterobacteriales. Plasmidmediated quinolone resistance genes and antibiotic. Fluoroquinoloneresistance plasmids can be transmitted horizontally and provide lowlevel resistance that facilitates the emergence of higher level resistance at therapeutic levels. Summary although plasmidmediated quinolone resistance pmqr was thought not to exist. The traditional understanding that quinolone resistance is acquired only through mutation and transmitted only vertically does not entirely account for. Qnr proteins are capable of protecting dna gyrase from quinolones and have been in circulation for at least 20 years 90. Journal of international medical research plasmidmediated. Nalidixic acid, the first quinolone to be used clinically, was introduced in 1967 for urinary tract infections. A highly fluoroquinoloneresistant isolate of aeromonas species was isolated from a wastewater treatment plant and found to possess multiple resistance mechanisms, including mutations in gyra and parc, efflux pumps, and plasmidmediated quinolone resistance pmqr genes. Complete sequencing of the incutype plasmid, pac3, present in the strain revealed a circular plasmid dna. The main aims of this study were to detect qnrencoding genes and to evaluate the clonal relatedness of qnrpositive enterobacter cloacae isolates.
Palmatine is a plasmidmediated quinolone resistance pmqr. Detection of plasmidmediated quinolone resistance in clinical. Characterization of plasmidmediated quinolone resistance by the. Full text investigation of six plasmidmediated quinolone resistance.
Detection of the plasmidmediated quinolone resistance. High prevalence of plasmidmediated quinolone resistance. The plasmidmediated quinolone resistance genes qnra, qnrb, qnrs, qepa, and aac6. Plasmidmediated resistance an overview sciencedirect. Ibcr were detected by pcr amplification of metagenomic dna from surface sediments of the. The qnrs1containing isolates corresponded to four pulsed. Ibcrpositive isolate were detected, representing 0. Since then, many other genes have been identified and the underlying mechanisms of resistance have been elucidated. Three mechanisms for plasmidmediated quinolone resistance pmqr have been discovered since 1998.
Map of the ecori fragment of pmg252 encoding quinolone resistance. Although considered as impossible due to the plasmid curing effect of quinolones courvalin, 1990, plasmidmediated quinolone resistance pmqr was first reported in 1998 from a klebsiella pneumoniae isolate in the usa munshi et al. Previous studies have shown that quinolone resistance arises by mutations in chromosomal genes. Transfer of resistance and plasmid analysis transfer of the plasmidmediated quinolone resistance markers from qnrpositive aeromonas isolates to e. Quinolone resistance from a transferable plasmid the lancet. The prevalence of carbapenemase genes and plasmidmediated. The bestdescribed form of pmqr is determined by the qnr group of genes. Transferable resistance to fluoroquinines and nalidixic acid has been found in a clinical isolate of k pneumoniae on a broad host range plasmid. The spread of plasmidmediated quinolone resistance determinants qnrlike determinants, aac6.
Pcr was used to investigate the occurrence of the plasmidencoded quinolone resistance determinants qnra and qnrs among diarrhoeagenic enterobacterial isolates recovered from hanoi, vietnam, during the period march 2001 to april 2002. Plasmidmediated quinolone resistance in salmonella. Introduction working as a senior technician at the central veterinary institute in lelystad nl since 1991 responsible for the daily routine regarding resistance monitoring nrl for antibiotic resistance in animals. The aim of this study was screening of resistantclinical isolates to fluoroquinolone antibiotics and detection of qnr and aac6. We have cloned the plasmidquinolone resistance gene, termed qnr, and found it in an integronlike environment upstream from qace. The objective of this study was to determine the prevalence of qnr in clinical isolates of k. Plasmidmediated quinolone resistance pmqr is a growing clinical concern worldwide. Summary although plasmidmediated quinolone resistance pmqr was thought not to exist before its discovery in 1998, the past decade has seen an explosion of research characterizing this phenomenon. Plasmidmediated quinolone resistance in salmonella serotypes isolated from chicken carcasses in turkey zafer ata 1, artun yibar 2, erdem arslan 3, kaan mustak4, elcin gunaydin5 1military veterinary school and educational central commandership, bursa, turkey 2uludag university, faculty of veterinary medicine, department of food hygiene and technology, 3department of pharmacology and. Such a plasmid can speed the development and spread of resistance to these valuable antimicrobial agents. After two decades of the discovery of plasmidmediated quinolone resistance pmqr, three different mechanisms have been associated to this phenomenon. Among 6,057 isolates, 17 qnrpositive isolates and 1 aac6.
Resistance to quinolones and fluoroquinolones is being increasingly reported among human but also veterinary isolates during the last two to. Prevalence of plasmidmediated quinolone resistance. In total, 162 escherichia coli isolates, 28 shigella isolates and three enterobacter cloacae isolates were negative for qnra, while a single ent. Prevalence and characterization of plasmidmediated. Plasmidmediated quinolone resistance determinants in. The spread of plasmidmediated quinolone resistance determinants qnra and qnrs was evaluated in a collection of 186 extendedspectrum. Mechanism of plasmid mediated quinolone resistance john h.
The prevalence of carbapenem resistance in enterobacteriaceae was 10% 515012. The qnr genes appear to have been acquired from chromosomal genes in aquatic bacteria, are usually associated with. Detection of plasmidmediated quinolone resistance genes. The bestdescribed form of pmqr is determined by the.