1
|
Belotindos LP, Tsunoda R, Villanueva MA, Nakajima C, Mingala CN, Suzuki Y. Characterisation of plasmids harbouring qnrA1, qnrS1, and qnrB4 in E. coli isolated in the Philippines from food-producing animals and their products. J Glob Antimicrob Resist 2022; 30:38-46. [PMID: 35447382 DOI: 10.1016/j.jgar.2022.04.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 03/19/2022] [Accepted: 04/11/2022] [Indexed: 10/18/2022] Open
Abstract
OBJECTIVES Determinants showing plasmid-mediated quinolone resistance, which usually leads to antimicrobial ineffectiveness, have become an emerging clinical problem. In our previous study in the Philippines, a high prevalence of Qnr determinants was found in clinical samples and food-producing animals and their food products. However, no qnr-carrying plasmids have been investigated in animals or animal-derived foods. Hence, in the present, we aimed to characterise qnr-carrying plasmids in Escherichia coli isolated from the food supply chain. METHODS Plasmids from 44 qnr-positive isolates were assigned to incompatibility groups by PCR-based replicon typing, and the presence of β-lactamase-encoding genes were investigated by PCR. Localisation of qnr in plasmids was determined by S1-PFGE and Southern blot hybridisation. The transferability of qnr-carrying plasmids was examined by conjugation analysis. RESULTS Overall, 77.3% (95%CI = 62.2 - 88.5) of the isolates harbouring qnr determinants were positive for seven plasmid types, and 56.8% concurrently harboured blaTEM-1. Plasmid IncFrepB was prevalent (65.9%, 95%CI = 50.1 - 79.5) among qnr determinants. Localisation of qnr determinants in IncFrepB and transferability of plasmids was further confirmed. CONCLUSIONS The current study proved that qnr in E. coli isolated from food-producing animals and their food products could spread via plasmid IncFrepB upon selective pressure with quinolones or other antimicrobials. Therefore, to curb the emergence and spread of qnr-harbouring bacteria in the Philippines, prudent use of antimicrobials in animal production and stricter hygiene and food handling are recommended.
Collapse
Affiliation(s)
- Lawrence P Belotindos
- Division of Bioresources, International Institute for Zoonosis Control Hokkaido University, Sapporo 001-0020, Japan; Biosafety and Environment Section, Philippine Carabao Center, Science City of Muñoz, Nueva Ecija 3120, Philippines.
| | - Risa Tsunoda
- Division of Bioresources, International Institute for Zoonosis Control Hokkaido University, Sapporo 001-0020, Japan.
| | - Marvin A Villanueva
- Biosafety and Environment Section, Philippine Carabao Center, Science City of Muñoz, Nueva Ecija 3120, Philippines.
| | - Chie Nakajima
- Division of Bioresources, International Institute for Zoonosis Control Hokkaido University, Sapporo 001-0020, Japan; International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Sapporo 001-0021, Japan.
| | - Claro N Mingala
- Livestock Biotechnology Center, Philippine Carabao Center, Science City of Muñoz, Nueva Ecija 3120, Philippines.
| | - Yasuhiko Suzuki
- Division of Bioresources, International Institute for Zoonosis Control Hokkaido University, Sapporo 001-0020, Japan; International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido University, Sapporo 001-0021, Japan.
| |
Collapse
|
2
|
Ribeiro ÁCDS, Martins WMBDS, Silva AAD, Gales AC, Rando DGG, Minarini LADR. Exposure to sub-inhibitory ciprofloxacin and nitrofurantoin concentrations increases recA gene expression in uropathogenic Escherichia coli: The role of RecA protein as a drug target. Eur J Pharm Sci 2020; 146:105268. [PMID: 32081832 DOI: 10.1016/j.ejps.2020.105268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/03/2020] [Accepted: 02/15/2020] [Indexed: 01/01/2023]
Abstract
Sub-inhibitory concentrations (sub-MIC) of antimicrobial agents can lead to genetic changes in bacteria, modulating the expression of genes related to bacterial stress and leading to drug resistance. Herein we describe the impact of sub-MIC of ciprofloxacin and nitrofurantoin on three uropathogenic Escherichia coli strains. Disk-diffusion assays with different antimicrobial agents were tested to detect phenotype alterations, and quantitative real-time PCR (qRT-PCR) was performed to analyze the expression of ompF and recA genes. Significant reduction on the susceptibility to ciprofloxacin and nitrofurantoin was detected on disk diffusion test. The qRT-PCR results revealed a 1.2-4.7 increase in recA expression in all E. coli studied, while the ompF expression varied. Because RecA was pointed as an important component to the development of drug resistance, molecular docking studies were performed with three experimentally known inhibitors of this enzyme. These studies aimed to understand the inhibitory binding mode of such compounds. The results confirmed the ADP/ATP binding site as a potential site of inhibitor recognition and a binding mode based on π-stacking interactions with Tyr103 and hydrogen bonds with Tyr264. These findings can be useful for guiding the search and design of new antimicrobial agents, mainly concerning the treatment of infections with resistant bacterial strains.
Collapse
Affiliation(s)
- Ághata Cardoso da Silva Ribeiro
- Universidade Federal de São Paulo - UNIFESP, Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Laboratório Multidisciplinar em Saúde e Meio Ambiente, Departamento de Ciências Farmacêuticas, Rua São Nicolau, 210 Diadema, SP, Brazil
| | - Willames Marcos Brasileiro da Silva Martins
- Laboratório Alerta, Division of Infectious Diseases, Department of Internal Medicine, Escola Paulista de Medicina/Universidade Federal de São Paulo - UNIFESP, Rua Pedro de Toledo, 781 São Paulom, SP, Brazil
| | - Adilson Aderito da Silva
- Universidade Presbiteriana Mackenzie, Centro de Ciências Sociais e Aplicadas, Rua da Consolação, 930, São Paulo, SP, Brazil
| | - Ana Cristina Gales
- Laboratório Alerta, Division of Infectious Diseases, Department of Internal Medicine, Escola Paulista de Medicina/Universidade Federal de São Paulo - UNIFESP, Rua Pedro de Toledo, 781 São Paulom, SP, Brazil
| | - Daniela Gonçales Galasse Rando
- Universidade Federal de São Paulo - UNIFESP, Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Grupo de Pesquisas Químico-Farmacêuticas da UNIFESP, Departamento de Ciências Farmacêuticas, Rua São Nicolau, 210, Diadema, SP, Brazil
| | - Luciene Andrade da Rocha Minarini
- Universidade Federal de São Paulo - UNIFESP, Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Laboratório Multidisciplinar em Saúde e Meio Ambiente, Departamento de Ciências Farmacêuticas, Rua São Nicolau, 210 Diadema, SP, Brazil.
| |
Collapse
|
3
|
Cold shock induces chromosomal qnr in Vibrio species and plasmid-mediated qnrS1 in Escherichia coli. Antimicrob Agents Chemother 2019:AAC.01472-19. [PMID: 31570402 DOI: 10.1128/aac.01472-19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
qnr genes are found in aquatic bacteria and preceded the development of synthetic quinolones. Their natural functions are unknown. We evaluated the expression of chromosomal qnr in Vibrio species in response to environmental stresses and DNA damaging agents. Sub-inhibitory concentrations of quinolones, but not other DNA damaging agents, induced the expression of chromosomal qnr by more than five times in Vibrio parahaemolyticus, Vibrio vulnificus, and Vibrio mytili Cold shock also induced the expression of qnr in V. parahaemolyticus, V. vulnificus, and V. mytili, as well as qnrS1 in Escherichia coli qnrS1 induction by cold shock was not altered in ΔihfA or ΔihfB mutants or in a strain over-expressing dnaA, that otherwise directly modulate qnrS1 induction by ciprofloxacin. In contrast, qnrS1 induction by cold shock was reduced in a ΔcspA mutant in the cold shock regulon compared to the wild type. In conclusion, cold shock as well as quinolones induce chromosomal qnr in Vibrio species, and the related qnrS1 in E. coli.
Collapse
|
4
|
van der Putten BCL, Remondini D, Pasquini G, Janes VA, Matamoros S, Schultsz C. Quantifying the contribution of four resistance mechanisms to ciprofloxacin MIC inEscherichia coli: a systematic review. J Antimicrob Chemother 2018; 74:298-310. [DOI: 10.1093/jac/dky417] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 09/16/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Boas C L van der Putten
- Amsterdam UMC, University of Amsterdam, Department of Global Health, Amsterdam Institute for Global Health and Development, Meibergdreef 9, Amsterdam, Netherlands
- Amsterdam UMC, University of Amsterdam, Department of Medical Microbiology, Meibergdreef 9, Amsterdam, Netherlands
| | - Daniel Remondini
- Department of Physics and Astronomy (DIFA), University of Bologna, Viale Berti Pichat 6/2, Bologna, Bologna, Italy
| | - Giovanni Pasquini
- Department of Physics and Astronomy (DIFA), University of Bologna, Viale Berti Pichat 6/2, Bologna, Bologna, Italy
| | - Victoria A Janes
- Amsterdam UMC, University of Amsterdam, Department of Medical Microbiology, Meibergdreef 9, Amsterdam, Netherlands
| | - Sébastien Matamoros
- Amsterdam UMC, University of Amsterdam, Department of Medical Microbiology, Meibergdreef 9, Amsterdam, Netherlands
| | - Constance Schultsz
- Amsterdam UMC, University of Amsterdam, Department of Global Health, Amsterdam Institute for Global Health and Development, Meibergdreef 9, Amsterdam, Netherlands
- Amsterdam UMC, University of Amsterdam, Department of Medical Microbiology, Meibergdreef 9, Amsterdam, Netherlands
| |
Collapse
|
5
|
Genes and Proteins Involved in qnrS1 Induction. Antimicrob Agents Chemother 2018; 62:AAC.00806-18. [PMID: 29914953 DOI: 10.1128/aac.00806-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Accepted: 06/05/2018] [Indexed: 11/20/2022] Open
Abstract
Expression of the quinolone resistance gene qnrS1 is increased by quinolones, but unlike induction of some other qnr genes, the bacterial SOS system is not involved and no lexA box is found upstream. Nonetheless, at least 205 bp of upstream sequence is required for induction to take place. An upstream sequence bound to beads trapped potential binding proteins from cell extracts that were identified by mass spectrometry as Dps, Fis, Ihf, Lrp, CysB, and YjhU. To further elucidate their role, a reporter plasmid linking the qnrS1 upstream sequence to lacZ was introduced into cells of the Keio collection with single-gene deletions and screened for lacZ expression. Mutants in ihfA and ihfB had decreased lacZ induction, while induction in a cysB mutant was increased and dps, fis, lrp, yjhU, and other mutants showed no change. The essential upstream sequence contains potential binding sites for Ihf and DnaA. A dnaA deletion could not be tested because it provides essential functions in cell replication; however, increased dnaA expression decreased qnrS1 induction while decreased dnaA expression enhanced it, implying a role for DnaA as a repressor. In a mobility shift assay, purified IhfA, IhfB, and DnaA proteins (but not CysB) were shown to bind to the upstream segment. Induction decreased in a gyrA quinolone-resistant mutant, indicating that GyrA also has a role. Thus, quinolones acting through proteins DnaA, GyrA, IhfA, and IhfB regulate expression of qnrS1.
Collapse
|
6
|
Ma G, Wu G, Li X, Wang H, Zhou M. Characterization of Ciprofloxacin Resistance in Laboratory-Derived Mutants of Vibrio parahaemolyticus with qnr Gene. Foodborne Pathog Dis 2018; 15:711-717. [PMID: 30074404 DOI: 10.1089/fpd.2018.2476] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Ciprofloxacin, a broad-spectrum fluoroquinolone, is a bactericidal antibiotic targeting DNA gyrase and DNA topoisomerase IV encoded by the gyrA and parC genes. Resistance to fluoroquinolones requires the accumulation of multiple mutations including those that alter target genes and increase drug efflux. To examine the development of fluoroquinolones resistance in Vibrio parahaemolyticus, ciprofloxacin induction and selection was used to obtain several resistant V. parahaemolyticus mutants, which showed decreased susceptibilities to quinolones, and increased or decreased susceptibility to other structurally unrelated antibiotics. Quinolone resistance-determining region mutations were characterized, and it was found that gyrA mutations occurred in some of the high-level resistant mutants although qnr was present in both wild-type susceptible and resistant mutant strains. The mutants showed increased qnr expression and exposure to sub-inhibitory concentrations of ciprofloxacin caused a further increase in qnr expression independently of the SOS system. Two mutants demonstrated increased expression of the VmeCD-VpoC pump gene that promotes quinolone efflux. In addition, some of the high-level resistance mutants significantly decreased bacterial fitness. These data suggested that multiple genes contributed to the enhanced ciprofloxacin resistance appeared in V. parahaemolyticus and that acquisition of ciprofloxacin resistance impaired bacterial fitness.
Collapse
Affiliation(s)
- Gengqin Ma
- School of Food Science and Engineering, Wuhan Polytechnic University , Wuhan, China
| | - Gaosheng Wu
- School of Food Science and Engineering, Wuhan Polytechnic University , Wuhan, China
| | - Xiaofang Li
- School of Food Science and Engineering, Wuhan Polytechnic University , Wuhan, China
| | - Hongxun Wang
- School of Food Science and Engineering, Wuhan Polytechnic University , Wuhan, China
| | - Min Zhou
- School of Food Science and Engineering, Wuhan Polytechnic University , Wuhan, China
| |
Collapse
|
7
|
Kaplan E, Marano RBM, Jurkevitch E, Cytryn E. Enhanced Bacterial Fitness Under Residual Fluoroquinolone Concentrations Is Associated With Increased Gene Expression in Wastewater-Derived qnr Plasmid-Harboring Strains. Front Microbiol 2018; 9:1176. [PMID: 29937755 PMCID: PMC6003256 DOI: 10.3389/fmicb.2018.01176] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 05/15/2018] [Indexed: 12/18/2022] Open
Abstract
Plasmids harboring qnr genes confer resistance to low fluoroquinolone concentrations. These genes are of significant clinical, evolutionary and environmental importance, since they are widely distributed in a diverse array of natural and clinical environments. We previously extracted and sequenced a large (∼185 Kbp) qnrB-harboring plasmid, and several small (∼8 Kbp) qnrS-harboring plasmids, from Klebsiella pneumoniae isolates from municipal wastewater biosolids, and hypothesized that these plasmids provide host bacteria a selective advantage in wastewater treatment plants (WWTPs) that often contain residual concentrations of fluoroquinolones. The objectives of this study were therefore to determine the effect of residual fluoroquinolone concentrations on the growth kinetics of qnr plasmid-harboring bacteria; and on the copy number of qnr plasmids and expression of qnr genes. Electrotransformants harboring either one of the two types of plasmids could grow at ciprofloxacin concentrations exceeding 0.5 μg ml-1, but growth was significantly decreased at concentrations higher than 0.1 μg ml-1. In contrast, plasmid-free strains failed to grow even at 0.05 μg ml-1. No differences were observed in plasmid copy number under the tested ciprofloxacin concentrations, but qnr expression increased incrementally from 0 to 0.4 μg ml-1, suggesting that the transcription of this gene is regulated by antibiotic concentration. This study reveals that wastewater-derived qnr plasmids confer a selective advantage in the presence of residual fluoroquinolone concentrations and provides a mechanistic explanation for this phenomenon.
Collapse
Affiliation(s)
- Ella Kaplan
- Department of Soil Chemistry, Plant Nutrition and Microbiology, Institute of Soil, Water and Environmental Sciences, Volcani Center, Agricultural Research Organization, Beit Dagan, Israel.,Department of Agroecology and Plant Health, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Roberto B M Marano
- Department of Soil Chemistry, Plant Nutrition and Microbiology, Institute of Soil, Water and Environmental Sciences, Volcani Center, Agricultural Research Organization, Beit Dagan, Israel.,Department of Agroecology and Plant Health, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Edouard Jurkevitch
- Department of Soil Chemistry, Plant Nutrition and Microbiology, Institute of Soil, Water and Environmental Sciences, Volcani Center, Agricultural Research Organization, Beit Dagan, Israel
| | - Eddie Cytryn
- Department of Soil Chemistry, Plant Nutrition and Microbiology, Institute of Soil, Water and Environmental Sciences, Volcani Center, Agricultural Research Organization, Beit Dagan, Israel
| |
Collapse
|
8
|
Machuca J, Recacha E, Briales A, Díaz-de-Alba P, Blazquez J, Pascual Á, Rodríguez-Martínez JM. Cellular Response to Ciprofloxacin in Low-Level Quinolone-Resistant Escherichia coli. Front Microbiol 2017; 8:1370. [PMID: 28769919 PMCID: PMC5516121 DOI: 10.3389/fmicb.2017.01370] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 07/05/2017] [Indexed: 11/13/2022] Open
Abstract
Bactericidal activity of quinolones has been related to a combination of DNA fragmentation, reactive oxygen species (ROS) production and programmed cell death (PCD) systems. The underlying molecular systems responsible for reducing bactericidal effect during antimicrobial therapy in low-level quinolone resistance (LLQR) phenotypes need to be clarified. To do this and also define possible new antimicrobial targets, the transcriptome profile of isogenic Escherichia coli harboring quinolone resistance mechanisms in the presence of a clinical relevant concentration of ciprofloxacin was evaluated. A marked differential response to ciprofloxacin of either up- or downregulation was observed in LLQR strains. Multiple genes implicated in ROS modulation (related to the TCA cycle, aerobic respiration and detoxification systems) were upregulated (sdhC up to 63.5-fold) in mutants with LLQR. SOS system components were downregulated (recA up to 30.7-fold). yihE, a protective kinase coding for PCD, was also upregulated (up to 5.2-fold). SdhC inhibition sensitized LLQR phenotypes (up to ΔLog = 2.3 after 24 h). At clinically relevant concentrations of ciprofloxacin, gene expression patterns in critical systems to bacterial survival and mutant development were significantly modified in LLQR phenotypes. Chemical inhibition of SdhC (succinate dehydrogenase) validated modulation of ROS as an interesting target for bacterial sensitization.
Collapse
Affiliation(s)
- Jesús Machuca
- Unidad Intercentros de Enfermedades Infecciosas, Microbiología y Medicina Preventiva, Hospital Universitario Virgen Macarena y Virgen del RocíoSeville, Spain
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de SevillaSevilla, Spain
| | - Esther Recacha
- Unidad Intercentros de Enfermedades Infecciosas, Microbiología y Medicina Preventiva, Hospital Universitario Virgen Macarena y Virgen del RocíoSeville, Spain
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de SevillaSevilla, Spain
| | - Alejandra Briales
- Red Española de Investigación en Patología Infecciosa, Instituto de Salud Carlos IIIMadrid, Spain
- Departamento de Microbiología, Universidad de SevillaSevilla, Spain
| | - Paula Díaz-de-Alba
- Unidad Intercentros de Enfermedades Infecciosas, Microbiología y Medicina Preventiva, Hospital Universitario Virgen Macarena y Virgen del RocíoSeville, Spain
| | - Jesús Blazquez
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de SevillaSevilla, Spain
- Red Española de Investigación en Patología Infecciosa, Instituto de Salud Carlos IIIMadrid, Spain
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones CientíficasMadrid, Spain
| | - Álvaro Pascual
- Unidad Intercentros de Enfermedades Infecciosas, Microbiología y Medicina Preventiva, Hospital Universitario Virgen Macarena y Virgen del RocíoSeville, Spain
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de SevillaSevilla, Spain
- Red Española de Investigación en Patología Infecciosa, Instituto de Salud Carlos IIIMadrid, Spain
| | - José-Manuel Rodríguez-Martínez
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de SevillaSevilla, Spain
- Red Española de Investigación en Patología Infecciosa, Instituto de Salud Carlos IIIMadrid, Spain
- Departamento de Microbiología, Universidad de SevillaSevilla, Spain
| |
Collapse
|
9
|
Unique Features of Aeromonas Plasmid pAC3 and Expression of the Plasmid-Mediated Quinolone Resistance Genes. mSphere 2017; 2:mSphere00203-17. [PMID: 28567445 PMCID: PMC5444012 DOI: 10.1128/msphere.00203-17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 05/07/2017] [Indexed: 11/29/2022] Open
Abstract
In the present study, plasmid pAC3 isolated from a highly fluoroquinolone-resistant isolate of Aeromonas species was sequenced and found to contain two fluoroquinolone resistance genes, aac(6′)-Ib-cr and qnrS2. Comparative analyses of plasmid pAC3 and other Aeromonas sp. IncU-type plasmids revealed a mobile insertion cassette element with a unique structure containing a qnrS2 gene and a typical miniature inverted-repeat transposable element (MITE) structure. This study also revealed that this MITE sequence appears in other Aeromonas species plasmids and chromosomes. Our results also demonstrate that the fluoroquinolone-dependent expression of qnrS2 is associated with rsd in E. coli DH5α harboring plasmid pAC3. Our findings suggest that the mobile element may play an important role in qnrS2 dissemination and that Aeromonas species constitute an important reservoir of fluoroquinolone resistance determinants in the environment. A highly fluoroquinolone-resistant 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 plasmid-mediated quinolone resistance (PMQR) genes. Complete sequencing of the IncU-type plasmid, pAC3, present in the strain revealed a circular plasmid DNA 15,872 bp long containing two PMQR genes [qnrS2 and aac(6′)-Ib-cr]. A mobile insertion cassette element containing the qnrS2 gene and a typical miniature inverted-repeat transposable element (MITE) structure was identified in the plasmid. The present study revealed that this MITE sequence appears in other Aeromonas species plasmids and chromosomes. Plasmid pAC3 was introduced into Escherichia coli, and its PMQR genes were expressed, resulting in the acquisition of resistance. Proteome analysis of the recipient E. coli strain harboring the plasmid revealed that aac(6′)-Ib-cr expression was constitutive and that qnrS2 expression was dependent upon fluoroquinolone stress through regulation by regulator of sigma D (Rsd). To the best of our knowledge, this is the first report to characterize a novel MITE sequence upstream of the PMQR gene within a mobile insertion cassette, as well as the regulation of qnrS2 expression. Our results suggest that this mobile element may play an important role in qnrS2 dissemination. IMPORTANCE In the present study, plasmid pAC3 isolated from a highly fluoroquinolone-resistant isolate of Aeromonas species was sequenced and found to contain two fluoroquinolone resistance genes, aac(6′)-Ib-cr and qnrS2. Comparative analyses of plasmid pAC3 and other Aeromonas sp. IncU-type plasmids revealed a mobile insertion cassette element with a unique structure containing a qnrS2 gene and a typical miniature inverted-repeat transposable element (MITE) structure. This study also revealed that this MITE sequence appears in other Aeromonas species plasmids and chromosomes. Our results also demonstrate that the fluoroquinolone-dependent expression of qnrS2 is associated with rsd in E. coli DH5α harboring plasmid pAC3. Our findings suggest that the mobile element may play an important role in qnrS2 dissemination and that Aeromonas species constitute an important reservoir of fluoroquinolone resistance determinants in the environment.
Collapse
|
10
|
Machuca J, Diaz de Alba P, Recacha E, Pascual Á, Rodriguez-Martinez JM. Cytotoxic Effect Associated with Overexpression of QNR Proteins in Escherichia coli. Microb Drug Resist 2017; 23:822-825. [PMID: 28287903 DOI: 10.1089/mdr.2016.0245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVE The objective was to evaluate the cytotoxic effect associated with overexpression of multiple Qnr-like plasmid-mediated quinolone resistance (PMQR) mechanisms in Escherichia coli. METHODS Coding regions of different PMQR genes (qnrA1, qnrB1, qnrC, qnrD1, qnrS1, and qepA2) and efsqnr were cloned into pET29a(+) vector and overexpressed in E. coli BL21. E. coli BL21 with and without an empty pET29a(+) vector were used as controls. The cytotoxic effect associated with PMQR mechanism overexpression was determined by transmission electron microscopy and viability assays. RESULTS Overexpressed qnr genes produced loss of bacterial viability in the range of 77-97% compared with the controls, comparable with loss of viability associated with EfsQnr overexpression (97%). No loss of viability was observed in E. coli overexpressing QepA2. In transmission electron microscopy assays, signs of cytotoxicity were observed in E. coli cells overexpressing EfsQnr and Qnr proteins (30-45% of the bacterial population showed morphological changes). Morphological changes were observed in less than 5% of bacterial populations from the control strains and E. coli overexpressing QepA2. CONCLUSIONS Overexpression of qnr genes produces a cytotoxic cellular and structural effect in E. coli, the magnitude of which varies depending on the family of Qnr proteins.
Collapse
Affiliation(s)
- Jesús Machuca
- 1 Unidad Intercentros de Enfermedades Infecciosas, Microbiología y Medicina Preventiva, Hospital Universitario Virgen Macarena , Seville, Spain
- 2 Institute of Biomedicine of Seville (IBiS) , Seville, Spain
| | - Paula Diaz de Alba
- 1 Unidad Intercentros de Enfermedades Infecciosas, Microbiología y Medicina Preventiva, Hospital Universitario Virgen Macarena , Seville, Spain
| | - Esther Recacha
- 1 Unidad Intercentros de Enfermedades Infecciosas, Microbiología y Medicina Preventiva, Hospital Universitario Virgen Macarena , Seville, Spain
| | - Álvaro Pascual
- 1 Unidad Intercentros de Enfermedades Infecciosas, Microbiología y Medicina Preventiva, Hospital Universitario Virgen Macarena , Seville, Spain
- 2 Institute of Biomedicine of Seville (IBiS) , Seville, Spain
- 3 Department of Microbiology, University of Seville , Seville, Spain
| | - José Manuel Rodriguez-Martinez
- 2 Institute of Biomedicine of Seville (IBiS) , Seville, Spain
- 3 Department of Microbiology, University of Seville , Seville, Spain
| |
Collapse
|
11
|
Plasmid-mediated quinolone resistance: Two decades on. Drug Resist Updat 2016; 29:13-29. [PMID: 27912841 DOI: 10.1016/j.drup.2016.09.001] [Citation(s) in RCA: 137] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/03/2016] [Accepted: 08/29/2016] [Indexed: 11/21/2022]
Abstract
After two decades of the discovery of plasmid-mediated quinolone resistance (PMQR), three different mechanisms have been associated to this phenomenon: target protection (Qnr proteins, including several families with multiple alleles), active efflux pumps (mainly QepA and OqxAB pumps) and drug modification [AAC(6')-Ib-cr acetyltransferase]. PMQR genes are usually associated with mobile or transposable elements on plasmids, and, in the case of qnr genes, are often incorporated into sul1-type integrons. PMQR has been found in clinical and environmental isolates around the world and appears to be spreading. Although the three PMQR mechanisms alone cause only low-level resistance to quinolones, they can complement other mechanisms of chromosomal resistance to reach clinical resistance level and facilitate the selection of higher-level resistance, raising a threat to the treatment of infections by microorganisms that host these mechanisms.
Collapse
|
12
|
Abstract
Three mechanisms for plasmid-mediated quinolone resistance (PMQR) have been discovered since 1998. 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. The qnr genes appear to have been acquired from chromosomal genes in aquatic bacteria, are usually associated with mobilizing or transposable elements on plasmids, and are often incorporated into sul1-type integrons. The second plasmid-mediated mechanism involves acetylation of quinolones with an appropriate amino nitrogen target by a variant of the common aminoglycoside acetyltransferase AAC(6')-Ib. The third mechanism is enhanced efflux produced by plasmid genes for pumps QepAB and OqxAB. PMQR has been found in clinical and environmental isolates around the world and appears to be spreading. The plasmid-mediated mechanisms provide only low-level resistance that by itself does not exceed the clinical breakpoint for susceptibility but nonetheless facilitates selection of higher-level resistance and makes infection by pathogens containing PMQR harder to treat.
Collapse
|
13
|
Abstract
Quinolone antimicrobials are synthetic and widely used in clinical medicine. Resistance emerged with clinical use and became common in some bacterial pathogens. Mechanisms of resistance include two categories of mutation and acquisition of resistance-conferring genes. Resistance mutations in one or both of the two drug target enzymes, DNA gyrase and DNA topoisomerase IV, are commonly in a localized domain of the GyrA and ParE subunits of the respective enzymes and reduce drug binding to the enzyme-DNA complex. Other resistance mutations occur in regulatory genes that control the expression of native efflux pumps localized in the bacterial membrane(s). These pumps have broad substrate profiles that include quinolones as well as other antimicrobials, disinfectants, and dyes. Mutations of both types can accumulate with selection pressure and produce highly resistant strains. Resistance genes acquired on plasmids can confer low-level resistance that promotes the selection of mutational high-level resistance. Plasmid-encoded resistance is due to Qnr proteins that protect the target enzymes from quinolone action, one mutant aminoglycoside-modifying enzyme that also modifies certain quinolones, and mobile efflux pumps. Plasmids with these mechanisms often encode additional antimicrobial resistances and can transfer multidrug resistance that includes quinolones. Thus, the bacterial quinolone resistance armamentarium is large.
Collapse
Affiliation(s)
- David C Hooper
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts
| | - George A Jacoby
- Lahey Hospital and Medical Center, Burlington, Massachusetts.,Harvard Medical School, Boston, Massachusetts
| |
Collapse
|
14
|
Abstract
OBJECTIVES Loop B is important for low-level quinolone resistance conferred by Qnr proteins. The role of individual amino acids within QnrS1 loop B in quinolone resistance and gyrase protection was assessed. METHODS qnrS1 and 11 qnrS1 alleles with site-directed Ala mutations in loop B were expressed in Escherichia coli BL21(DE3) and proteins were purified by affinity chromatography. Ciprofloxacin MICs were determined with and without IPTG. Gyrase DNA supercoiling was measured with and without ciprofloxacin IC50 and with various concentrations of QnrS1 proteins. RESULTS Wild-type QnrS1 and QnrS1 with Asn-110→Ala and Arg-111→Ala substitutions increased the ciprofloxacin MIC 12-fold in BL21(DE3), although QnrS1 with Gln-107→Ala replacement increased it 2-fold more than wild-type did. However, QnrS1 with Ala substitutions at His-106, Val-108, Ser-109, Met-112, Tyr-113, Phe-114, Cys-115 and Ser-116 increased ciprofloxacin MIC 1.4- to 8-fold less than wild-type QnrS1. Induction by 10-1000 μM IPTG increased ciprofloxacin MICs for all mutants, reaching values similar to those for wild-type. Purified wild-type and mutated proteins differed in protection of gyrase from ciprofloxacin action. Wild-type QnrS1 produced complete protection of gyrase supercoiling from ciprofloxacin (1.8 μM) action at 0.05 nM and half protection at 0.5 pM, whereas QnrS1 with Ala replacements that conferred the least increase in ciprofloxacin MICs also required the highest QnrS1 concentrations for protection. CONCLUSIONS Key individual residues in QnrS1 loop B affect ciprofloxacin resistance and gyrase protection from ciprofloxacin action, supporting the concept that loop B is key for interaction with gyrase necessary for quinolone resistance.
Collapse
Affiliation(s)
- María M Tavío
- Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA Microbiología, Departamento de Ciencias Clínicas, Universidad de Las Palmas de Gran Canaria, Las Palmas de G.C., España
| | | | - David C Hooper
- Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
15
|
Induction of plasmid-carried qnrS1 in Escherichia coli by naturally occurring quinolones and quorum-sensing signal molecules. Antimicrob Agents Chemother 2013; 57:4031-4. [PMID: 23689721 DOI: 10.1128/aac.00337-13] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Naturally occurring quinolone and quinolone-like compounds, such as quinine, 2-hydroxyquinoline, 4-hydroxyquinoline, and 2-heptyl-3-hydroxy-4(1H)-quinolone, increased expression of qnrS1 in Escherichia coli 2.3- to 11.2-fold, similar to the synthetic quinolone ciprofloxacin. In contrast, chromosomal qnrVS1 of Vibrio splendidus was not induced by these compounds. Molecules associated with quorum sensing, such as N-3-hydroxybutyryl-homoserine lactone (HSL), N-hexanoyl-HSL, and N-3-(oxododecanoyl)-HSL, did not show an induction effect on either qnrS1 or qnrVS1 at the tested concentrations.
Collapse
|
16
|
Phylogenetic analysis of chromosomally determined qnr and related proteins. Antimicrob Agents Chemother 2013; 57:1930-4. [PMID: 23318805 DOI: 10.1128/aac.02080-12] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
qnr genes were discovered on plasmids by their ability to reduce quinolone susceptibility, but homologs can be found in the genomes of at least 92 Gram-negative, Gram-positive, and strictly anaerobic bacterial species. The related pentapeptide repeat protein-encoding mfpA gene is present in the genome of at least 19 species of Mycobacterium and 10 other Actinobacteria species. The native function of these genes is not yet known.
Collapse
|
17
|
Briales A, Rodriguez-Martinez JM, Velasco C, Machuca J, Diaz de Alba P, Blazquez J, Pascual A. Exposure to diverse antimicrobials induces the expression of qnrB1, qnrD and smaqnr genes by SOS-dependent regulation. J Antimicrob Chemother 2012; 67:2854-9. [DOI: 10.1093/jac/dks326] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|