In total, 162 escherichia coli isolates, 28 shigella isolates and three enterobacter cloacae isolates were negative for qnra, while a single ent. Unexpected occurrence of plasmidmediated quinolone. Detection of the plasmidmediated quinolone resistance. Journal of international medical research plasmidmediated. Such a plasmid can speed the development and spread of resistance to these valuable antimicrobial agents. Qnr proteins are capable of protecting dna gyrase from quinolones and have been in circulation for at least 20 years 90. Although resistance was low in wildtype strains, higher levels of quinolone resistance arose readily by mutation. 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. We have cloned the plasmidquinolone resistance fication of qnr, its gene product. Ibcr were detected by pcr amplification of metagenomic dna from surface sediments of the. Although plasmidmediated quinolone resistance pmqr genes confer only a low level of resistance to. Here we report the cloning of qnr, the novel plasmidencoded quinolone resistance gene, the amplification and puri. Detection of plasmidmediated quinolone resistance in clinical.
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 plasmidmediated mechanisms provide only lowlevel resistance that by itself does not exceed the clinical breakpoint for susceptibility but nonetheless facilitates selection of higher level. Ibcrproducing escherichia coli peng wang,1 longfei hu,1 zhihui hao2 1agricultural biopharmaceutical laboratory, qingdao agricultural university, qingdao 266109, peoples republic of china. Bacterial plasmidmediated quinolone resistance genes in aquatic environments in china. The prevalence of carbapenem resistance in enterobacteriaceae was 10% 515012. Transferable resistance to fluoroquinines and nalidixic acid has been found in a clinical isolate of k pneumoniae on a broad host range plasmid. Plasmidmediated quinolone resistance determinants in. The spread of plasmidmediated quinolone resistance determinants qnra and qnrs was evaluated in a collection of 186 extendedspectrum. After two decades of the discovery of plasmidmediated quinolone resistance pmqr, three different mechanisms have been associated to this phenomenon. Prevalence of plasmidmediated quinolone resistance genes. Summary although plasmidmediated quinolone resistance pmqr was thought not to exist. 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.
The plasmidmediated quinolone resistance genes qnra, qnrb, qnrs, qepa, and aac6. Pdf mechanism of plasmidmediated quinolone resistance. The increase in plasmidmediated quinolone resistance among nts isolated from humans in the united states. Full text investigation of six plasmidmediated quinolone resistance. 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. 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. The dissemination of these genes in latin american countries, where the prescription of fluoroquinolones is high, has been described in several studies. Plasmidmediated quinolone resistance in salmonella. Plasmidmediated quinolone resistance in typhoidal salmonellae. Plasmidmediated quinolone resistance current knowledge. Resistance to fluoroquinolones fq in uropathogenic escherichia coli upec has emerged as a growing problem. Prevalence and characterization of plasmidmediated. Resistance was soon observed and could also be readily selected in the laboratory. Investigation of six plasmidmediated quinolone resistance genes among clinical isolates of pseudomonas.
Among 6,057 isolates, 17 qnrpositive isolates and 1 aac6. Prevalence of plasmidmediated quinolone resistance genes among ciprofloxacinnonsusceptible escherichia coli and klebsiella pneumoniae isolated from blood cultures in korea. Resistance to quinolones and fluoroquinolones is being increasingly reported among human but also veterinary isolates during the last two to. Mechanisms prevalence of plasmidmediated quinolone resistance genes in clinical enterobacteria from argentina ezequiel albornoz,1 celeste lucero,1 genara romero,1 mar. Map of the ecori fragment of pmg252 encoding quinolone resistance. Plasmidmediated quinolone resistance pmqr was late in being discovered.
Characterization of plasmidmediated quinolone resistance by the. 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. Palmatine is a plasmidmediated quinolone resistance pmqr. In a more recent study transferable plasmidmediated quinolone resistance associated with qnr was reported in quinoloneresistant clinical strains of e. Abstract the spread of antimicrobial resistance from human activity derived sources to natural habitats implicates wildlife as potential vectors of antimicrobial resistance transfer. Pdf the animal reservoir of plasmidmediated quinolone resistance pmqr and. The qnrs1containing isolates corresponded to four pulsed. High prevalence 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. Plasmidmediated quinolone resistance genes and antibiotic. Quinolone resistance from a transferable plasmid the lancet. Pdf plasmidmediated quinolone resistance in typhoidal.
The plasmidmediated quinolone resistance pmqr genes have changed the resistance pattern to quinolones, especially among enterobacteriales. Plasmidmediated quinolone resistance among nontyphi. 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. Transfer of resistance and plasmid analysis transfer of the plasmidmediated quinolone resistance markers from qnrpositive aeromonas isolates to e. The qnr genes appear to have been acquired from chromosomal genes in aquatic bacteria, are usually associated with. We have cloned the plasmidquinolone resistance gene, termed qnr, and found it in an integronlike. We have cloned the plasmidquinolone resistance gene, termed qnr, and found it in an integronlike environment upstream from qace. To assess the prevalence of plasmidmediated quinolone resistance using polymerase chain reaction pcr with qnr and mcbgspecific primers, jacoby et al. Prevalence of plasmidmediated quinolone resistance in norwegian and swedish clinical isolates of escherchia coli and klebsiella spp. A preliminary report from south india article pdf available in indian journal of medical microbiology 321. Palmatine is a plasmidmediated quinolone resistance pmqr inhibitor that restores the activity of ciprofloxacin against qnrs and aac6. Ibcr, and plasmidmediated efflux pumps qepa and oqxab. Six isolates were susceptible to nalidixic acid and presented reduced susceptibility to cipro. The discovery in 1998 123 of qnr, a plasmidmediated horizontally transferable gene encoding quinolone resistance, has shed light on these phenomena.
Complete sequencing of the incutype plasmid, pac3, present in the strain revealed a circular plasmid dna. The prevalence of carbapenemase genes and plasmidmediated. The main aims of this study were to detect qnrencoding genes and to evaluate the clonal relatedness of qnrpositive enterobacter cloacae isolates. The discovery in 1998 123 of qnr, a plasmidmediated hor. Nalidixic acid, the first quinolone to be used clinically, was introduced in 1967 for urinary tract infections. Plasmidmediated quinolone resistance determinants in quinolone. To our knowledge, this is the first report of plasmidmediated quinolone resistance in s. Plasmidmediated quinolone resistance determinants in quinoloneresistant escherichia coli isolated from patients with bacteremia in. 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. The plasmid mediated quinolone resistance genes qnra, qnrb, qnrs, qepa, and aac6. 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. Development and evaluation of a multiplex pcr for eight plasmidmediated quinoloneresistance determinants.
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. 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. Since then, many other genes have been identified and the underlying mechanisms of resistance have been elucidated. Bacterial plasmidmediated quinolone resistance genes in aquatic. Prevalence of plasmidmediated quinolone resistance in. The worldwide emergence of plasmidmediated quinolone resistance ari robicsek, george a jacoby, david c hooper fluoroquinolone resistance is emerging in gramnegative pathogens worldwide.
The first plasmidmediated quinolone resistance gene, qnra1, was detected in 1998. Plasmidmediated resistance has only recently been documented for the fluoroquinolones. Prevalence of plasmidmediated quinolone resistance. Moreover, three mechanisms for plasmidmediated quinolone resistance pmqr have been discovered since 1998 and include qnr proteins, the aminoglycoside acetyltransferase aac6. Detection of chromosomal and plasmidmediated quinolone. Ibcrpositive isolate were detected, representing 0. Plasmidmediated resistance an overview sciencedirect. Jacoby infectious disease department, lahey clinic, burlington, ma 01805 communicated by paul c. Chromosomal mutations and plasmidmediated quinolone resistance pmqr determinants have been implicated.
Detection of plasmidmediated quinolone resistance genes. Two copies of orf5, found in integrons in6 and in7, surround these genes. High incidence of plasmidmediated quinolone resistance. The aim of this study was screening of resistantclinical isolates to fluoroquinolone antibiotics and detection of qnr and aac6. The objective of this study was to determine the prevalence of qnr in clinical isolates of k. The bestdescribed form of pmqr is determined by the qnr group of genes. 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. Fluoroquinoloneresistance plasmids can be transmitted horizontally and provide lowlevel resistance that facilitates the emergence of higher level resistance at therapeutic levels. These genes, likely originating in aquatic organisms, code for pentapeptide repeat proteins. The spread of plasmidmediated quinolone resistance determinants qnrlike determinants, aac6. 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. Recently, a multiresistance plasmid was discovered that encodes transferable resistance to quinolones.
Previous studies have shown that quinolone resistance arises by mutations in chromosomal genes. No plasmidmediated quinolone resistance gene was detected in the isolates from seville. The traditional understanding that quinolone resistance is acquired only through mutation and transmitted only vertically does not entirely account for. The bestdescribed form of pmqr is determined by the. Mechanism of plasmidmediated quinolone resistance pnas. Plasmidmediated quinolone resistance pmqr is a growing clinical concern worldwide. Pdf plasmidmediated quinolone resistance and lactamases in. Three mechanisms for plasmidmediated quinolone resistance pmqr have been discovered since 1998. Development and evaluation of a multiplex pcr for eight.
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