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Tariq FN, Shafiq M, Khawar N, Habib G, Gul H, Hayat A, Rehman MU, Moussa IM, Mahmoud EA, Elansary HO. The functional repertoire of AmpR in the AmpC β-lactamase high expression and decreasing β-lactam and aminoglycosides resistance in ESBL Citrobacter freundii. Heliyon 2023; 9:e19486. [PMID: 37662790 PMCID: PMC10472055 DOI: 10.1016/j.heliyon.2023.e19486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 08/12/2023] [Accepted: 08/23/2023] [Indexed: 09/05/2023] Open
Abstract
Citrobacter freundii is characterized by AmpC β-lactamases that develop resistance to β-lactam antibiotics. The production of extended-spectrum β-lactamase (ESBL) is substantially high in Escherichia coli, C. freundii, Enterobacter cloacae, and Serratia marcescens, but infrequently explored in C. freundii. The present investigation characterized the ESBL C. freundii and delineated the genes involved in decrease in antibiotics resistance. We used the VITEK-2 system and Analytical Profile Index (API) kit to characterize and identify the Citrobacter isolates. The mRNA level of AmpC and AmpR was determined by RT-qPCR, and gel-shift assay was performed to evaluate protein-DNA binding. Here, a total of 26 Citrobacter strains were isolated from COVID-19 patients that showed varying degrees of antibiotic resistance. We examined and characterized the multidrug resistant C. freundii that showed ESBL production. The RT-qPCR analysis revealed that the AmpC mRNA expression is significantly high followed by a high level of AmpR. We sequenced the AmpC and AmpR genes that revealed the AmpR has four novel mutations in comparison to the reference genome namely; Thr64Ile, Arg86Ser, Asp135Val, and Ile183Leu while AmpC remained intact. The ΔAmpR mutant analysis revealed that the AmpR positively regulates oxidative stress response and decreases β-lactam and aminoglycosides resistance. The AmpC and AmpR high expression was associated with resistance to tazobactam, ampicillin, gentamicin, nitrofurantoin, and cephalosporins whereas AmpR deletion reduced β-lactam and aminoglycosides resistance. We conclude that AmpR is a positive regulator of AmpC that stimulates β-lactamases which inactivate multiple antibiotics.
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Affiliation(s)
- Falak Naz Tariq
- Department of Microbiology, Abbottabad University of Science and Technology, Havelian, Abbottabad, 22500, Pakistan
| | - Mehreen Shafiq
- Department of Microbiology, Abbottabad University of Science and Technology, Havelian, Abbottabad, 22500, Pakistan
| | - Nadeem Khawar
- Institute of Pathology and Diagnostic Medicine, Khyber Medical University, Peshawar, 25000, Pakistan
| | - Gul Habib
- Department of Microbiology, Abbottabad University of Science and Technology, Havelian, Abbottabad, 22500, Pakistan
| | - Haji Gul
- College of Animal Science and Technology, Anhui Agricultural University, No. 130 Changjiang West Road, Hefei, 230036, China
| | - Azam Hayat
- Department of Microbiology, Abbottabad University of Science and Technology, Havelian, Abbottabad, 22500, Pakistan
| | - Mujaddad Ur Rehman
- Department of Microbiology, Abbottabad University of Science and Technology, Havelian, Abbottabad, 22500, Pakistan
| | - Ihab Mohamed Moussa
- Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia
| | - Eman A. Mahmoud
- Department of Food Industries, Faculty of Agriculture, Damietta University, Damietta, Egypt
| | - Hosam O. Elansary
- Department of Plant Production, College of Food & Agriculture Sciences, King Saud University, P.O. Box 2460, Riyadh, 11451, Saudi Arabia
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Kumawat M, Nabi B, Daswani M, Viquar I, Pal N, Sharma P, Tiwari S, Sarma DK, Shubham S, Kumar M. Role of bacterial efflux pump proteins in antibiotic resistance across microbial species. Microb Pathog 2023:106182. [PMID: 37263448 DOI: 10.1016/j.micpath.2023.106182] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/24/2023] [Accepted: 05/30/2023] [Indexed: 06/03/2023]
Abstract
Efflux proteins are transporter molecules that actively pump out a variety of substrates, including antibiotics, from cells to the environment. They are found in both Gram-positive and Gram-negative bacteria and eukaryotic cells. Based on their protein sequence homology, energy source, and overall structure, efflux proteins can be divided into seven groups. Multidrug efflux pumps are transmembrane proteins produced by microbes to enhance their survival in harsh environments and contribute to antibiotic resistance. These pumps are present in all bacterial genomes studied, indicating their ancestral origins. Many bacterial genes encoding efflux pumps are involved in transport, a significant contributor to antibiotic resistance in microbes. Efflux pumps are widely implicated in the extrusion of clinically relevant antibiotics from cells to the extracellular environment and, as such, represent a significant challenge to antimicrobial therapy. This review aims to provide an overview of the structures and mechanisms of action, substrate profiles, regulation, and possible inhibition of clinically relevant efflux pumps. Additionally, recent advances in research and the pharmacological exploitation of efflux pump inhibitors as a promising intervention for combating drug resistance will be discussed.
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Affiliation(s)
- Manoj Kumawat
- Department of Microbiology, ICMR- National Institute for Research in Environmental Health, Bhopal, 462030, India
| | - Bilkees Nabi
- Department of Biochemistry & Biochemical Engineering, SHUATS, Allahabad, 211007, India
| | - Muskan Daswani
- Department of Biotechnology, SantHirdaram Girls College, Bhopal, 462030, India
| | - Iqra Viquar
- Department of Biotechnology, SantHirdaram Girls College, Bhopal, 462030, India
| | - Namrata Pal
- Department of Microbiology, ICMR- National Institute for Research in Environmental Health, Bhopal, 462030, India
| | - Poonam Sharma
- Department of Microbiology, ICMR- National Institute for Research in Environmental Health, Bhopal, 462030, India
| | - Shikha Tiwari
- Department of Microbiology, ICMR- National Institute for Research in Environmental Health, Bhopal, 462030, India
| | - Devojit Kumar Sarma
- Department of Microbiology, ICMR- National Institute for Research in Environmental Health, Bhopal, 462030, India
| | - Swasti Shubham
- Department of Microbiology, ICMR- National Institute for Research in Environmental Health, Bhopal, 462030, India
| | - Manoj Kumar
- Department of Microbiology, ICMR- National Institute for Research in Environmental Health, Bhopal, 462030, India.
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Thompson DK, Sharkady SM. Genomic Insights into Drug Resistance Determinants in Cedecea neteri, A Rare Opportunistic Pathogen. Microorganisms 2021; 9:microorganisms9081741. [PMID: 34442820 PMCID: PMC8401664 DOI: 10.3390/microorganisms9081741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/09/2021] [Accepted: 08/13/2021] [Indexed: 11/16/2022] Open
Abstract
Cedecea, a genus in the Enterobacteriaceae family, includes several opportunistic pathogens reported to cause an array of sporadic acute infections, most notably of the lung and bloodstream. One species, Cedecea neteri, is associated with cases of bacteremia in immunocompromised hosts and has documented resistance to different antibiotics, including β-lactams and colistin. Despite the potential to inflict serious infections, knowledge about drug resistance determinants in Cedecea is limited. In this study, we utilized whole-genome sequence data available for three environmental strains (SSMD04, M006, ND14a) of C. neteri and various bioinformatics tools to analyze drug resistance genes in this bacterium. All three genomes harbor multiple chromosome-encoded β-lactamase genes. A deeper analysis of β-lactamase genes in SSMD04 revealed four metallo-β-lactamases, a novel variant, and a CMY/ACT-type AmpC putatively regulated by a divergently transcribed AmpR. Homologs of known resistance-nodulation-cell division (RND)-type multidrug efflux pumps such as OqxB, AcrB, AcrD, and MdtBC were also identified. Genomic island prediction for SSMD04 indicated that tolC, involved in drug and toxin export across the outer membrane of Gram-negative bacteria, was acquired by a transposase-mediated genetic transfer mechanism. Our study provides new insights into drug resistance mechanisms of an environmental microorganism capable of behaving as a clinically relevant opportunistic pathogen.
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Identification of a blaVIM-1-Carrying IncA/C 2 Multiresistance Plasmid in an Escherichia coli Isolate Recovered from the German Food Chain. Microorganisms 2020; 9:microorganisms9010029. [PMID: 33374123 PMCID: PMC7824508 DOI: 10.3390/microorganisms9010029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/13/2020] [Accepted: 12/21/2020] [Indexed: 11/17/2022] Open
Abstract
Within the German national monitoring of zoonotic agents, antimicrobial resistance determination also targets carbapenemase-producing (CP) Escherichia coli by selective isolation from food and livestock. In this monitoring in 2019, the CP E. coli 19-AB01133 was recovered from pork shoulder. The isolate was assigned to the phylogenetic group B1 and exhibited the multi-locus sequence-type ST5869. Molecular investigations, including whole genome sequencing, of 19-AB01133 revealed that the isolate carried the resistance genes blaVIM-1, blaSHV-5 and blaCMY-13 on a self-transmissible IncA/C2 plasmid. The plasmid was closely related to the previously described VIM-1-encoding plasmid S15FP06257_p from E. coli of pork origin in Belgium. Our results indicate an occasional spread of the blaVIM-1 gene in Enterobacteriaceae of the European pig population. Moreover, the blaVIM-1 located on an IncA/C2 plasmid supports the presumption of a new, probably human source of carbapenemase-producing Enterobacteriaceae (CPE) entering the livestock and food chain sector.
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Chiu CH, Lee JJ, Wang MH, Chu C. Genetic analysis and plasmid-mediated bla CMY-2 in Salmonella and Shigella and the Ceftriaxone Susceptibility regulated by the ISEcp-1 tnpA-bla CMY-2-blc-sugE. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2020; 54:649-657. [PMID: 32169530 DOI: 10.1016/j.jmii.2020.01.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 01/18/2020] [Accepted: 01/21/2020] [Indexed: 12/01/2022]
Abstract
BACKGROUND Nontyphoid Salmonella and Shigella can cause gastroenteritis in humans. Ceftriaxone (CRO) has been used to treat their infection, however, development of CRO resistance are often associated with plasmid-mediated blaCMY. Here, we investigated the presence of plasmid-mediated ISEcp-1 tnpA-blaCMY-2-blc-sugE and the role of these genes in regulation of CRO susceptibility in different hosts. METHODS 194 strains of Salmonella serovars and Shigella were tested for CRO susceptibility. Non-susceptibility strains were examined for plasmid-mediated ISEcp-1 tnpA-blaCMY-2-blc-sugE by PCR amplification, Southern blot, and DNA sequencing. The plasmid profiles were determined by HindIII-digested restriction fragment length polymorphism (RFLP). Four recombinant plasmids with different genes from ISEcp-1 tnpA-blaCMY-2-blc-sugE were constructed and then were transferred into Escherichia coli and different Salmonella serovars to evaluate the CRO susceptibility. RESULTS Among 20 CRO-nonsusceptible isolates of Salmonella Choleraesuis (5), S. Typhimurium (4), S. Mons (1), S. Stanley (2) and Shigella sonnei (8) with plasmid-mediated blaCMY-2, 19 isolates carried the ISEcp-1 tnpA-blaCMY-2-blc-sugE and only one isolate with tnpA-blaCMY-2. Transformation of these plasmids into E. coli pir116 produced multidrug resistance. Furthermore, PCR-RFLP analysis determined 5 different plasmid profiles and identical RFLP pattern between S. Typhimurium and S. sonnei. Transformation of the recombinant plasmids into E. coli and different Salmonella serovars resulted in phenotypes ranging from susceptible to resistant (especially inducible resistance) to CRO that were dependent on the genes, and host. CONCLUSION The CRO susceptibility associated with the ISEcp-1 tnpA-blaCMY-2-blc-sugE element is regulated positively by ISEcp-1 tnpA and SugE and negatively regulated by Blc and unknown species-dependent host factor(s).
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Affiliation(s)
- Cheng-Hsun Chiu
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan, ROC; Division of Pediatric Infectious Diseases, Chang Gung Children's Hospital, Taoyuan, Taiwan, ROC
| | - Jen-Jain Lee
- Medical Laboratory Division, Chiayi Branch, Taichung Veterans General Hospital, No.600, Sec. 2, Shixian Rd., Chiayi City, 60090, Taiwan, ROC
| | - Mei-Hui Wang
- Department of Microbiology, Immunology, and Biopharmaceuticals, College of Life Sciences, National Chiayi University, Chiayi, Taiwan, ROC
| | - Chishih Chu
- Department of Microbiology, Immunology, and Biopharmaceuticals, College of Life Sciences, National Chiayi University, Chiayi, Taiwan, ROC.
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Chen CM, Huang M, Wu HJ, Guo MK, Wu LT. Identification of CFE-2, a new plasmid-encoded AmpC β-lactamase from a clinical isolate of Citrobacter freundii. Int J Antimicrob Agents 2018; 52:421-424. [PMID: 29944954 DOI: 10.1016/j.ijantimicag.2018.06.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 03/13/2018] [Accepted: 06/16/2018] [Indexed: 10/28/2022]
Abstract
A clinical isolate of Citrobacter freundii (JA99) obtained from a bile culture of a Taiwanese patient was found to produce a plasmid-encoded β-lactamase conferring resistance to oxyimino-cephalosporins and cephamycins. Resistance arising from production of the β-lactamase could be transferred by conjugation with an IncW plasmid (pJA99) into Escherichia coli J53. The substrate and inhibition profiles of this enzyme resembled that of an AmpC β-lactamase. The resistance gene of pJA99, cloned and expressed in E. coli DH5α, was shown to contain an open reading frame showing 92% amino acid identity with the plasmid-encoded enzyme CFE-1 of E. coli KU6400. DNA sequence analysis also identified a gene upstream of ampC in pJA99 whose sequence was 95.0% identical to the ampR gene from E. coli KU6400. In addition, orf1, the fumarate operon (frdABCD), blc, lolB and repB surrounding the ampR-ampC genes in C. freundii were identified. This DNA fragment was absent in other Citrobacter spp. Therefore, we describe a new plasmid-encoded AmpC β-lactamase, named CFE-2. This study highlights the emergence of broad-spectrum cephalosporin resistance in C. freundii owing to a new type of AmpC β-lactamase.
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Affiliation(s)
- Chih-Ming Chen
- Department of Health Food, Chung Chou University of Science and Technology, Changhua, Taiwan; Division of Infectious Diseases, Department of Internal Medicine, Tungs' Taichung MetroHarbor Hospital, Taichung, Taiwan
| | - Mei Huang
- Division of Infectious Diseases, Chang Bing Show Chwan Memorial Hospital, Changhua, Taiwan
| | - Hwa-Jene Wu
- Department of Laboratory Medicine, Buddhist Tzu Chi Medical Foundation, Taiwan
| | - Ming-Kai Guo
- Graduate Institute of Biomedical Sciences and Department of Microbiology, China Medical University, Taichung, Taiwan
| | - Lii-Tzu Wu
- Graduate Institute of Biomedical Sciences and Department of Microbiology, China Medical University, Taichung, Taiwan.
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Sonnevend Á, Yahfoufi N, Ghazawi A, Jamal W, Rotimi V, Pál T. Contribution of horizontal gene transfer to the emergence of VIM-4 carbapenemase producer Enterobacteriaceae in Kuwait. Infect Drug Resist 2017; 10:469-478. [PMID: 29263683 PMCID: PMC5724420 DOI: 10.2147/idr.s149321] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Carbapenem-resistant Enterobacteriaceae encountered in countries of the Arabian Peninsula usually produce OXA-48-like and New Delhi metallo-beta-lactamases (NDM) carbapenemases. However, a temporary increase in VIM-4-producing, clonally unrelated Enterobacteriaceae strains was described earlier in a Kuwaiti hospital. We investigated the genetic support of blaVIM-4 in six Klebsiella pneumoniae strains, one Escherichia coli, and one Enterobacter cloacae strain and compared it to that of VIM-4-producing isolates from other countries of the region. Five K. pneumoniae strains and the E. coli strain from Kuwait carried an ~165 kb IncA/C-type plasmid indistinguishable by restriction fragment length polymorphism. The complete sequence of one of them (pKKp4-VIM) was established. pKKp4-VIM exhibited extensive similarities to episomes pKP-Gr642 carrying blaVIM-19 encountered in Greece and to the partially sequenced pCC416 harboring blaVIM-4 detected in Italy. In other countries of the region, the only similar plasmid was the one detected in the isolate from the UAE. In all Kuwaiti strains, irrespective of the species and their VIM plasmids, the blaVIM-4 gene was located within the same integron structure (In416), different from those of other countries of the region. Our data show that the spread of this IncA/C plasmid and particularly that of the In416 integron caused a considerable, albeit temporary, increase in the rate of mostly clonally unrelated VIM-producing Enterobacteriaceae strains of multiple species. Monitoring of such events is of high importance as the interference with the spread of mobile genetic elements may represent a formidable challenge to infection control.
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Affiliation(s)
- Ágnes Sonnevend
- Department of Medical Microbiology and Immunology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, UAE
| | - Nour Yahfoufi
- Department of Medical Microbiology and Immunology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, UAE.,Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Akela Ghazawi
- Department of Medical Microbiology and Immunology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, UAE
| | - Wafaa Jamal
- Department of Microbiology, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait
| | - Vincent Rotimi
- Department of Microbiology, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait
| | - Tibor Pál
- Department of Medical Microbiology and Immunology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, UAE
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Abstract
CFE-1 is a unique plasmid-encoded AmpC β-lactamase with the regulator gene ampR. It imparts high resistance to most cephalosporins with constitutive high-level β-lactamase activity. CFE-1 is a unique plasmid-encoded AmpC β-lactamase with the regulator gene ampR. It imparts high resistance to most cephalosporins with constitutive high-level β-lactamase activity. Here, the β-lactamase activities and expression levels of ampC with or without ampR were investigated. Results suggested that the resistance of CFE-1 to cephalosporins is caused by a substitution in AmpR, in which the Asp at position 135 is modified to Ala to allow the constitutive high-level expression (derepression) of ampC.
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Ingti B, Paul D, Maurya AP, Bora D, Chanda DD, Chakravarty A, Bhattacharjee A. Occurrence of bla DHA-1 mediated cephalosporin resistance in Escherichia coli and their transcriptional response against cephalosporin stress: a report from India. Ann Clin Microbiol Antimicrob 2017; 16:13. [PMID: 28320396 PMCID: PMC5359928 DOI: 10.1186/s12941-017-0189-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 03/10/2017] [Indexed: 01/21/2023] Open
Abstract
Background Treatment alternatives for DHA-1 harboring strains are challenging as it confers resistance to broad spectrum cephalosporins and may further limit treatment option when expressed at higher levels. Therefore, this study was designed to know the prevalence of DHA genes and analyse the transcription level of DHA-1 against different β-lactam stress. Methods Screening of AmpC β-lactamase phenotypically by modified three dimensional extract method followed by Antimicrobial Susceptibility and MIC determination. Genotyping screening of β-lactamase genes was performed by PCR assay followed by their sequencing. The blaDHA-1 transcriptional response was evaluated under different cephalosporin stress by RT PCR. Transferability of blaDHA gene was performed by transformation and conjugation and plasmid incompatibility typing, DNA fingerprinting by enterobacterial repetitive intergenic consensus sequences PCR. Results 16 DHA-1 genes were screened positive from 176 Escherichia coli isolates and primer extension analysis showed a significant increase in DHA-1 mRNA transcription in response to cefotaxime at 8 µg/ml (6.99 × 102 fold), ceftriaxone at 2 µg/ml (2.63 × 103 fold), ceftazidime at 8 µg/ml (7.06 × 103 fold) and cefoxitin at 4 µg/ml (3.60 × 104 fold) when compared with untreated strain. These transcription data were found significant when analyzed statistically using one way ANOVA. Four different ESBL genes were detected in 10 isolates which include CTX-M (n = 6), SHV (n = 4), TEM (n = 3) and OXA-10 (n = 1), whereas, carbapenemase gene (NDM) was detected only in one isolate. Other plasmid mediated AmpC β-lactamases CIT (n = 9), EBC (n = 2) were detected in nine isolates. All DHA-1 genes detected were encoded in plasmid and incompatibility typing from the transformants indicated that the plasmid encoding blaDHA-1 was carried mostly by the FIA and L/M Inc group. Conclusion This study demonstrates the prevalence of DHA-1 gene in this region and highlights high transcription of DHA-1 when induced with different β-lactam antibiotics. Therefore, cephalosporin treatment must be restricted for the patients infected with pathogen expressing this resistance determinant.
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Affiliation(s)
- Birson Ingti
- Department of Microbiology, Assam University, Silchar, 788011, India
| | - Deepjyoti Paul
- Department of Microbiology, Assam University, Silchar, 788011, India
| | | | - Debajyoti Bora
- Department of Statistics, Dibrugarh University, Dibrugarh, India
| | - Debadatta Dhar Chanda
- Department of Microbiology, Silchar Medical College and Hospital, Silchar, 788014, India
| | - Atanu Chakravarty
- Department of Microbiology, Silchar Medical College and Hospital, Silchar, 788014, India
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Ingti B, Laskar MA, Choudhury S, Maurya AP, Paul D, Talukdar AD, Choudhury MD, Dhar D, Chakravarty A, Bhattacharjee A. Molecular and in silico analysis of a new plasmid-mediated AmpC β-lactamase (CMH-2) in clinical isolates of Klebsiella pneumoniae. INFECTION GENETICS AND EVOLUTION 2017; 48:34-39. [DOI: 10.1016/j.meegid.2016.12.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 11/22/2016] [Accepted: 12/08/2016] [Indexed: 11/16/2022]
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Bajaj P, Singh NS, Virdi JS. Escherichia coli β-Lactamases: What Really Matters. Front Microbiol 2016; 7:417. [PMID: 27065978 PMCID: PMC4811930 DOI: 10.3389/fmicb.2016.00417] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 03/14/2016] [Indexed: 01/09/2023] Open
Abstract
Escherichia coli strains belonging to diverse pathotypes have increasingly been recognized as a major public health concern. The β-lactam antibiotics have been used successfully to treat infections caused by pathogenic E. coli. However, currently, the utility of β-lactams is being challenged severely by a large number of hydrolytic enzymes – the β-lactamases expressed by bacteria. The menace is further compounded by the highly flexible genome of E. coli, and propensity of resistance dissemination through horizontal gene transfer and clonal spread. Successful management of infections caused by such resistant strains requires an understanding of the diversity of β-lactamases, their unambiguous detection, and molecular mechanisms underlying their expression and spread with regard to the most relevant information about individual bacterial species. Thus, this review comprises first such effort in this direction for E. coli, a bacterial species known to be associated with production of diverse classes of β-lactamases. The review also highlights the role of commensal E. coli as a potential but under-estimated reservoir of β-lactamases-encoding genes.
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Affiliation(s)
- Priyanka Bajaj
- Microbial Pathogenicity Laboratory, Department of Microbiology, University of Delhi South Campus New Delhi, India
| | - Nambram S Singh
- Microbial Pathogenicity Laboratory, Department of Microbiology, University of Delhi South Campus New Delhi, India
| | - Jugsharan S Virdi
- Microbial Pathogenicity Laboratory, Department of Microbiology, University of Delhi South Campus New Delhi, India
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Structural basis for carbapenem-hydrolyzing mechanisms of carbapenemases conferring antibiotic resistance. Int J Mol Sci 2015; 16:9654-92. [PMID: 25938965 PMCID: PMC4463611 DOI: 10.3390/ijms16059654] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 04/21/2015] [Accepted: 04/22/2015] [Indexed: 02/06/2023] Open
Abstract
Carbapenems (imipenem, meropenem, biapenem, ertapenem, and doripenem) are β-lactam antimicrobial agents. Because carbapenems have the broadest spectra among all β-lactams and are primarily used to treat infections by multi-resistant Gram-negative bacteria, the emergence and spread of carbapenemases became a major public health concern. Carbapenemases are the most versatile family of β-lactamases that are able to hydrolyze carbapenems and many other β-lactams. According to the dependency of divalent cations for enzyme activation, carbapenemases can be divided into metallo-carbapenemases (zinc-dependent class B) and non-metallo-carbapenemases (zinc-independent classes A, C, and D). Many studies have provided various carbapenemase structures. Here we present a comprehensive and systematic review of three-dimensional structures of carbapenemase-carbapenem complexes as well as those of carbapenemases. We update recent studies in understanding the enzymatic mechanism of each class of carbapenemase, and summarize structural insights about regions and residues that are important in acquiring the carbapenemase activity.
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Mondon M, Hur S, Vadlamani G, Rodrigues P, Tsybina P, Oliver A, Mark BL, Vocadlo DJ, Blériot Y. Selective trihydroxyazepane NagZ inhibitors increase sensitivity of Pseudomonas aeruginosa to β-lactams. Chem Commun (Camb) 2014; 49:10983-5. [PMID: 24136176 DOI: 10.1039/c3cc46646a] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
AmpC β-lactamase confers resistance to β-lactam antibiotics in many Gram negative bacteria. Inducible expression of AmpC requires an N-acetylglucosaminidase termed NagZ. Here we describe the synthesis and characterization of hydroxyazepane inhibitors of NagZ. We find that these inhibitors enhance the susceptibility of clinically relevant Pseudomonas aeruginosa to β-lactams.
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Affiliation(s)
- Martine Mondon
- Université de Poitiers, IC2MP, UMR CNRS 7285, Équipe "Synthése Organique" Groupe Glycochimie, 4 rue Michel Brunet, 86022 Poitiers Cedex, France.
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Zienkiewicz M, Kern-Zdanowicz I, Carattoli A, Gniadkowski M, Cegłowski P. Tandem multiplication of the IS26-flanked amplicon with the bla(SHV-5) gene within plasmid p1658/97. FEMS Microbiol Lett 2013; 341:27-36. [PMID: 23330672 DOI: 10.1111/1574-6968.12084] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 01/04/2013] [Accepted: 01/11/2013] [Indexed: 11/28/2022] Open
Abstract
The IncF plasmid p1658/97 (c. 125 kb) from Escherichia coli isolates recovered during a clonal outbreak in a hospital in Warsaw, Poland, in 1997 contains the extended-spectrum β-lactamase (ESBL) gene bla(SHV-5), originated from the Klebsiella pneumoniae chromosome. A region containing the bla(SHV-5) gene is flanked by two IS26 copies and its copy number multiplies spontaneously within p1658/97 and RecA-deficient E. coli strains. Here, we demonstrate that the amplified IS26-bla(SHV-5) units were arranged in tandems, containing up to more than 10 units, which could raise ceftazidime MICs for host strains from 4 μg mL(-1) to more than 128 μg mL(-1). Successive deletions within p1658/97, located outside the amplifiable module and encompassing even as little as c. 15% of the plasmid, blocked the amplification. Moreover, the complementing re-introduction of the deleted fragments in trans did not restore the process. Similarly, insertions of a 1-kb DNA fragment into the amplicon inhibited its self-multiplication ability. The module was able to transmit into another IS26-containing plasmid by recombination. The results prompted us to speculate that local DNA structure, especially favorable in p1658/97, might have been responsible for the IS26-bla(SHV-5) multiplication ability.
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Affiliation(s)
- Maksymilian Zienkiewicz
- Department of Microbial Biochemistry, Institute of Biochemistry and Biophysics of Polish Academy of Sciences, Warsaw, Poland.
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15
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Kolbusz MA, Slotboom DJ, Lolkema JS. Genomic distribution of the small multidrug resistance protein EmrE over 29Escherichia colistrains reveals two forms of the protein. FEBS J 2012; 280:244-55. [DOI: 10.1111/febs.12065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 11/08/2012] [Accepted: 11/12/2012] [Indexed: 11/29/2022]
Affiliation(s)
- Magdalena A. Kolbusz
- Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute; University of Groningen; The Netherlands
| | - Dirk J. Slotboom
- Membrane Enzymology, Groningen Biomolecular Sciences and Biotechnology Institute; University of Groningen; The Netherlands
| | - Juke S. Lolkema
- Molecular Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute; University of Groningen; The Netherlands
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16
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Harris PNA, Ferguson JK. Antibiotic therapy for inducible AmpC β-lactamase-producing Gram-negative bacilli: what are the alternatives to carbapenems, quinolones and aminoglycosides? Int J Antimicrob Agents 2012; 40:297-305. [PMID: 22824371 DOI: 10.1016/j.ijantimicag.2012.06.004] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Revised: 06/06/2012] [Accepted: 06/07/2012] [Indexed: 01/15/2023]
Abstract
Some bacteria that possess chromosomally determined AmpC β-lactamases may express these enzymes at a high level following exposure to β-lactams, either by induction or selection for derepressed mutants. This may lead to clinical failure even if an isolate initially tests susceptible in vitro, a phenomenon best characterised by third-generation cephalosporin therapy for Enterobacter bacteraemia or meningitis. Several other Enterobacteriaceae, such as Serratia marcescens, Citrobacter freundii, Providencia spp. and Morganella morganii (often termed the 'ESCPM' group), may also express high levels of AmpC. However, the risk of clinical failure with β-lactams that test susceptible in vitro is less clear in these species than for Enterobacter. Laboratories frequently do not report β-lactam or β-lactamase inhibitor combination drug susceptibilities for ESCPM organisms, encouraging alternative therapy with quinolones, aminoglycosides or carbapenems. However, quinolones and carbapenems present problems with selective pressure for multiresistant organisms, and aminoglycosides with potential toxicity. The risk of emergent AmpC-mediated resistance for non-Enterobacter spp. appears rare in clinical studies. Piperacillin/tazobactam may remain effective and may be less selective for AmpC derepressed mutants than cephalosporins. The potential roles for agents such as cefepime or trimethoprim/sulfamethoxazole are also discussed. Clinical studies that better define optimal treatment for this group of bacteria are required.
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Affiliation(s)
- P N A Harris
- Hunter Area Pathology, Pathology North, John Hunter Hospital, New Lambton, NSW, Australia.
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17
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García-Fernández A, Villa L, Moodley A, Hasman H, Miriagou V, Guardabassi L, Carattoli A. Multilocus sequence typing of IncN plasmids. J Antimicrob Chemother 2011; 66:1987-91. [DOI: 10.1093/jac/dkr225] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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18
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Galani I, Souli M, Mitchell N, Chryssouli Z, Giamarellou H. Presence of plasmid-mediated quinolone resistance in Klebsiella pneumoniae and Escherichia coli isolates possessing blaVIM-1 in Greece. Int J Antimicrob Agents 2010; 36:252-4. [PMID: 20580536 DOI: 10.1016/j.ijantimicag.2010.05.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2010] [Accepted: 05/17/2010] [Indexed: 10/19/2022]
Abstract
Amongst nalidixic acid-resistant, ciprofloxacin-susceptible Escherichia coli and Klebsiella pneumoniae clinical isolates recovered over a 5-month period from inpatients and outpatients of Attikon University General Hospital (Athens, Greece), only one E. coli was positive for qnrB2 and one K. pneumoniae was positive for qnrA1. Both isolates were extended-spectrum beta-lactamase-negative, metallo-beta-lactamase-positive and carried the bla(VIM-1) gene. Neither of the isolates had mutations in gyrA and parC or carried aac(6')-Ib-cr or qepA. The K. pneumoniae isolate also harboured bla(CMY-13) on the same transferable plasmid with qnrA1. This is the first report of a qnrA1-positive K. pneumoniae and qnrB2-positive E. coli harbouring a concurrent bla(VIM-1) gene.
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Affiliation(s)
- I Galani
- 4th Department of Internal Medicine, Molecular Biology Section, Athens University School of Medicine, Athens, Greece.
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19
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Smet A, Martel A, Persoons D, Dewulf J, Heyndrickx M, Herman L, Haesebrouck F, Butaye P. Broad-spectrum β-lactamases amongEnterobacteriaceaeof animal origin: molecular aspects, mobility and impact on public health. FEMS Microbiol Rev 2010; 34:295-316. [DOI: 10.1111/j.1574-6976.2009.00198.x] [Citation(s) in RCA: 159] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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20
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Balcewich MD, Stubbs KA, He Y, James TW, Davies GJ, Vocadlo DJ, Mark BL. Insight into a strategy for attenuating AmpC-mediated beta-lactam resistance: structural basis for selective inhibition of the glycoside hydrolase NagZ. Protein Sci 2009; 18:1541-51. [PMID: 19499593 DOI: 10.1002/pro.137] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
NagZ is an exo-N-acetyl-beta-glucosaminidase, found within Gram-negative bacteria, that acts in the peptidoglycan recycling pathway to cleave N-acetylglucosamine residues off peptidoglycan fragments. This activity is required for resistance to cephalosporins mediated by inducible AmpC beta-lactamase. NagZ uses a catalytic mechanism involving a covalent glycosyl enzyme intermediate, unlike that of the human exo-N-acetyl-beta-glucosaminidases: O-GlcNAcase and the beta-hexosaminidase isoenzymes. These latter enzymes, which remove GlcNAc from glycoconjugates, use a neighboring-group catalytic mechanism that proceeds through an oxazoline intermediate. Exploiting these mechanistic differences we previously developed 2-N-acyl derivatives of O-(2-acetamido-2-deoxy-D-glucopyranosylidene)amino-N-phenylcarbamate (PUGNAc), which selectively inhibits NagZ over the functionally related human enzymes and attenuate antibiotic resistance in Gram-negatives that harbor inducible AmpC. To understand the structural basis for the selectivity of these inhibitors for NagZ, we have determined its crystallographic structure in complex with N-valeryl-PUGNAc, the most selective known inhibitor of NagZ over both the human beta-hexosaminidases and O-GlcNAcase. The selectivity stems from the five-carbon acyl chain of N-valeryl-PUGNAc, which we found ordered within the enzyme active site. In contrast, a structure determination of a human O-GlcNAcase homologue bound to a related inhibitor N-butyryl-PUGNAc, which bears a four-carbon chain and is selective for both NagZ and O-GlcNAcase over the human beta-hexosamnidases, reveals that this inhibitor induces several conformational changes in the active site of this O-GlcNAcase homologue. A comparison of these complexes, and with the human beta-hexosaminidases, reveals how selectivity for NagZ can be engineered by altering the 2-N-acyl substituent of PUGNAc to develop inhibitors that repress AmpC mediated beta-lactam resistance.
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Affiliation(s)
- Misty D Balcewich
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
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21
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Abstract
SUMMARY AmpC beta-lactamases are clinically important cephalosporinases encoded on the chromosomes of many of the Enterobacteriaceae and a few other organisms, where they mediate resistance to cephalothin, cefazolin, cefoxitin, most penicillins, and beta-lactamase inhibitor-beta-lactam combinations. In many bacteria, AmpC enzymes are inducible and can be expressed at high levels by mutation. Overexpression confers resistance to broad-spectrum cephalosporins including cefotaxime, ceftazidime, and ceftriaxone and is a problem especially in infections due to Enterobacter aerogenes and Enterobacter cloacae, where an isolate initially susceptible to these agents may become resistant upon therapy. Transmissible plasmids have acquired genes for AmpC enzymes, which consequently can now appear in bacteria lacking or poorly expressing a chromosomal bla(AmpC) gene, such as Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis. Resistance due to plasmid-mediated AmpC enzymes is less common than extended-spectrum beta-lactamase production in most parts of the world but may be both harder to detect and broader in spectrum. AmpC enzymes encoded by both chromosomal and plasmid genes are also evolving to hydrolyze broad-spectrum cephalosporins more efficiently. Techniques to identify AmpC beta-lactamase-producing isolates are available but are still evolving and are not yet optimized for the clinical laboratory, which probably now underestimates this resistance mechanism. Carbapenems can usually be used to treat infections due to AmpC-producing bacteria, but carbapenem resistance can arise in some organisms by mutations that reduce influx (outer membrane porin loss) or enhance efflux (efflux pump activation).
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22
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Ahmed AM, Shimamoto T. Emergence of a cefepime- and cefpirome-resistant Citrobacter freundii clinical isolate harbouring a novel chromosomally encoded AmpC beta-lactamase, CMY-37. Int J Antimicrob Agents 2008; 32:256-61. [PMID: 18619820 DOI: 10.1016/j.ijantimicag.2008.04.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2008] [Revised: 04/18/2008] [Accepted: 04/18/2008] [Indexed: 11/18/2022]
Abstract
Citrobacter freundii strain 4306 was isolated from a urine specimen of a patient in March 2006 in Palestine. This strain showed a unique multidrug resistance phenotype, as it was resistant both to 7-alpha-methoxy- and oxyimino-cephalosporins, including cefepime, cefpirome and monobactams, in addition to quinolones, streptomycin and trimethoprim/sulfamethoxazole. Clavulanic acid did not act synergistically with cephalosporins by the double-disk synergy test. Molecular characterisation showed that the resistance to 7-alpha-methoxy- and oxyimino-cephalosporins was due to a novel AmpC beta-lactamase, designated CMY-37, with an isoelectric point of approximately 9.0. CMY-37 is a variant of C. freundii chromosomal AmpC enzymes with at least seven amino acid substitutions. One of these substitutions, L316I, is located within the R2 loop that is considered the hotspot region responsible for the extended substrate spectrum in class C beta-lactamases. The blaCMY-37 gene was cloned and expressed in Escherichia coli TG1. CMY-37 is chromosomally encoded and is not associated with ISEcp1-like element. Phylogenetic analysis suggested that CMY-37 is the origin of many plasmid-mediated AmpC beta-lactamases. This study highlights the emergence of cefepime and cefpirome resistance in C. freundii owing to a new type of AmpC beta-lactamase.
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Affiliation(s)
- Ashraf M Ahmed
- Laboratory of Food Microbiology and Hygiene, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, Japan
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23
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Bay DC, Rommens KL, Turner RJ. Small multidrug resistance proteins: A multidrug transporter family that continues to grow. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1778:1814-38. [DOI: 10.1016/j.bbamem.2007.08.015] [Citation(s) in RCA: 183] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2007] [Revised: 08/07/2007] [Accepted: 08/14/2007] [Indexed: 11/17/2022]
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24
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Han HL, Jang SJ, Park G, Kook JK, Shin JH, Shin SH, Kim DM, Cheon JS, Moon DS, Park YJ. Identification of an atypical integron carrying an IS26-disrupted aadA1 gene cassette in Acinetobacter baumannii. Int J Antimicrob Agents 2008; 32:165-9. [PMID: 18565738 DOI: 10.1016/j.ijantimicag.2008.03.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2008] [Revised: 03/13/2008] [Accepted: 03/14/2008] [Indexed: 11/28/2022]
Abstract
An unusual class 1 integron was identified that carries an IS26-disrupted aadA1 gene cassette (designated as 'integron-IS26') in an imipenem-resistant Acinetobacter baumannii (IRAB) outbreak strain. DNA sequencing revealed that integron-IS26 contained two gene cassettes, the aac(6')-Im cassette and a peculiar aadA1 cassette that was disrupted by IS26 (disrupted aadA1 cassette). Southern blotting localised integron-IS26 to the chromosome. Nested polymerase chain reaction (PCR) was performed to define the frequency of integron-IS26 in five groups of bacteria. Nested PCR identified integron-IS26 in 19 (73.1%) of 26 clinical outbreak strains of IRAB, 10 (100%) of 10 IRAB isolated from environmental cultures, 3 (13.0%) of 23 imipenem-susceptible A. baumannii (ISAB) non-outbreak strains, 1 (3.6%) of 28 netilmicin- and tobramycin-resistant A. baumannii and none of the netilmicin- and tobramycin-resistant Pseudomonas aeruginosa. In conclusion, we have identified a novel class I integron that carries the aac(6')-Im cassette and an IS26-disrupted copy of aadA1 (integron-IS26) in most IRAB outbreak strains and in a few ISAB non-outbreak control strains. Integron-IS26 is located chromosomally.
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Affiliation(s)
- Hu Lin Han
- Research Center for Resistant Cells, Chosun University Medical School, Gwang-Ju, South Korea
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25
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CMY-20, a novel AmpC-type β-lactamase from South African clinical Escherichia coli isolates. Diagn Microbiol Infect Dis 2008; 60:405-8. [DOI: 10.1016/j.diagmicrobio.2007.11.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2007] [Revised: 11/20/2007] [Accepted: 11/20/2007] [Indexed: 11/19/2022]
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26
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Outbreak caused by a multidrug-resistant Klebsiella pneumoniae clone carrying blaVIM-12 in a university hospital. J Clin Microbiol 2008; 46:1005-8. [PMID: 18199780 DOI: 10.1128/jcm.01573-07] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
From November 2006 to April 2007, nine nonrepetitive isolates of Klebsiella pneumoniae with reduced susceptibility or resistance to carbapenems were recovered from clinical specimens from separate patients hospitalized in a tertiary care hospital. The imipenem-EDTA synergy test was positive for all isolates. PCR, sequencing, and transferability experiments revealed the novel bla(VIM-12) metallo-beta-lactamase gene, which was plasmid mediated and located in a class 1 integron. Pulsed-field gel electrophoresis demonstrated a single macrorestriction pattern, indicating the clonal spread of VIM-12-producing K. pneumoniae.
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27
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Su LH, Chu C, Cloeckaert A, Chiu CH. An epidemic of plasmids? Dissemination of extended-spectrum cephalosporinases among Salmonella and other Enterobacteriaceae. ACTA ACUST UNITED AC 2007; 52:155-68. [PMID: 18093140 DOI: 10.1111/j.1574-695x.2007.00360.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
CTX-M- and AmpC-type beta-lactamases comprise the two most rapidly growing populations among the extended-spectrum cephalosporinases. The evolution and dissemination of resistance genes encoding these enzymes occur mostly through the transmission of plasmids. The high prevalence of clinical isolates of Enterobacteriaceae producing the plasmid-mediated extended-spectrum cephalosporinases resembles an epidemic of plasmids, and has generated serious therapeutic problems. This review describes the emergence and worldwide spread of various classes of plasmid-mediated extended-spectrum cephalosporinases in Salmonella and other Enterobacteriaceae, the transfer mechanism of the plasmids, detection methods, and therapeutic choices.
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Affiliation(s)
- Lin-Hui Su
- Department of Clinical Pathology, Chang Gung Memorial Hospital, Taoyuan, Taiwan
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28
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Ahmed AM, Motoi Y, Sato M, Maruyama A, Watanabe H, Fukumoto Y, Shimamoto T. Zoo animals as reservoirs of gram-negative bacteria harboring integrons and antimicrobial resistance genes. Appl Environ Microbiol 2007; 73:6686-90. [PMID: 17720829 PMCID: PMC2075039 DOI: 10.1128/aem.01054-07] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A total of 232 isolates of gram-negative bacteria were recovered from mammals, reptiles, and birds housed at Asa Zoological Park, Hiroshima prefecture, Japan. Forty-nine isolates (21.1%) showed multidrug resistance phenotypes and harbored at least one antimicrobial resistance gene. PCR and DNA sequencing identified class 1 and class 2 integrons and many beta-lactamase-encoding genes, in addition to a novel AmpC beta-lactamase gene, bla(CMY-26). Furthermore, the plasmid-mediated quinolone resistance genes qnr and aac(6')-Ib-cr were also identified.
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Affiliation(s)
- Ashraf M Ahmed
- Laboratory of Food Microbiology and Hygiene, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan.
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29
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Stubbs KA, Balcewich M, Mark BL, Vocadlo DJ. Small Molecule Inhibitors of a Glycoside Hydrolase Attenuate Inducible AmpC-mediated β-Lactam Resistance. J Biol Chem 2007; 282:21382-91. [PMID: 17439950 DOI: 10.1074/jbc.m700084200] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The increasing spread of plasmid-borne ampC-ampR operons is of considerable medical importance, since the AmpC beta-lactamases they encode confer high level resistance to many third generation cephalosporins. Induction of AmpC beta-lactamase from endogenous or plasmid-borne ampC-ampR operons is mediated by a catabolic inducer molecule, 1,6-anhydro-N-acetylmuramic acid (MurNAc) tripeptide, an intermediate of the cell wall recycling pathway derived from the peptidoglycan. Here we describe a strategy for attenuating the antibiotic resistance associated with the ampC-ampR operon by blocking the formation of the inducer molecule using small molecule inhibitors of NagZ, the glycoside hydrolase catalyzing the formation of this inducer molecule. The structure of the NagZ-inhibitor complex provides insight into the molecular basis for inhibition and enables the development of inhibitors with 100-fold selectivity for NagZ over functionally related human enzymes. These PUGNAc-derived inhibitors reduce the minimal inhibitory concentration (MIC) values for several clinically relevant cephalosporins in both wild-type and AmpC-hyperproducing strains lacking functional AmpD.
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Affiliation(s)
- Keith A Stubbs
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6
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30
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Nakano R, Okamoto R, Nagano N, Inoue M. Resistance to gram-negative organisms due to high-level expression of plasmid-encoded ampC β-lactamase blaCMY-4 promoted by insertion sequence ISEcp1. J Infect Chemother 2007; 13:18-23. [PMID: 17334724 DOI: 10.1007/s10156-006-0483-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Accepted: 10/10/2006] [Indexed: 10/23/2022]
Abstract
A Klebsiella pneumoniae strain, KU6500, which showed resistance to extended-spectrum beta-lactams and produced the plasmid-encoded AmpC beta-lactamase CMY-4, was identified from clinical isolates in Japan. The aim of this study was to identify the mechanism of the high-level expression of blaCMY-4. Sequence analysis indicated that the promoter element of Citrobacter freundii was conserved, but the insertion sequence ISEcp1 coding with the putative promoter element, was inserted into the AmpR binding site. We determined the influence of the promoter on blaCMY-4 expression and beta-lactam resistance. Two recombinant plasmids containing the entire blaCMY-4 gene, with or without the ISEcp1-mediated promoter sequences, were constructed and named pMWampC and pMWISEcp1, respectively. Escherichia coli DH5alpha (pMWISEcp1) was resistant to almost all beta-lactams tested and E. coli DH5alpha (pMWampC) was susceptible to all, except for cephalothin. In addition, the activity of each promoter was measured by subcloning the element into a promoterless luciferase plasmid pGL3-Basic vector. The expression of the putative promoter of ISEcp1 was 18.9-fold higher than that of C. freundii. These results suggest that the putative promoter element of ISEcp1 is necessary for the high-level expression of blaCMY-4 to confer resistance to extended-spectrum cephalosporins.
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Affiliation(s)
- Ryuichi Nakano
- School of Medicine and Environmental Infectious Diseases, Graduate School of Medical Sciences, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555, Japan.
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31
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Ktari S, Arlet G, Mnif B, Gautier V, Mahjoubi F, Ben Jmeaa M, Bouaziz M, Hammami A. Emergence of multidrug-resistant Klebsiella pneumoniae isolates producing VIM-4 metallo-beta-lactamase, CTX-M-15 extended-spectrum beta-lactamase, and CMY-4 AmpC beta-lactamase in a Tunisian university hospital. Antimicrob Agents Chemother 2006; 50:4198-201. [PMID: 17015633 PMCID: PMC1694011 DOI: 10.1128/aac.00663-06] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Klebsiella pneumoniae clinical isolates resistant to carbapenems were recovered from 11 patients in the hospital of Sfax, Tunisia. The isolates were closely related as shown by pulsed-field gel electrophoresis, and they produced VIM-4 metallo-enzyme, CTX-M-15 extended-spectrum beta-lactamase, and CMY-4 AmpC enzyme. The bla(VIM-4) gene is part of a class 1 integron.
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Affiliation(s)
- Sonia Ktari
- Laboratoire de Microbiologie, CHU Habib Bourguiba, Sfax, Tunisie
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32
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Rossolini GM, Docquier JD. New β-lactamases: a paradigm for the rapid response of bacterial evolution in the clinical setting. Future Microbiol 2006; 1:295-308. [PMID: 17661642 DOI: 10.2217/17460913.1.3.295] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Production of β-lactamases is one of the most common mechanisms of bacterial resistance to β-lactam antibiotics. In the clinical setting, the introduction of new classes of β-lactams has invariably been followed by the emergence of new β-lactamases capable of degrading them, as a paradigmatic example of rapid bacterial evolution under a rapidly changing selective environment. The scope of this article is to provide an overview on the recent evolution of β-lactamase-mediated resistance among bacterial pathogens. Focus is on the mechanisms of evolution and dissemination of enzymes of greater clinical impact, including the extended-spectrum β-lactamases, the AmpC-type β-lactamases and the carbapenemases, which are currently responsible for emerging resistance to the most recent and powerful β-lactams (the expanded-spectrum cephalosporins and the carbapenems) among major Gram-negative pathogens such as Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter.
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Affiliation(s)
- Gian Maria Rossolini
- University of Siena, Department of Molecular Biology, Section of Microbiology, Policlinico Santa Maria alle Scotte, Siena, Italy.
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33
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Schmidtke AJ, Hanson ND. Model system to evaluate the effect of ampD mutations on AmpC-mediated beta-lactam resistance. Antimicrob Agents Chemother 2006; 50:2030-7. [PMID: 16723562 PMCID: PMC1479098 DOI: 10.1128/aac.01458-05] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mutations within the structural gene of ampD can lead to AmpC overproduction and increases in beta-lactam MICs in organisms with an inducible ampC. However, identification of mutations alone cannot predict the impact that those mutations have on AmpD function. Therefore, a model system was designed to determine the effect of ampD mutations on ceftazidime MICs using an AmpD(-) mutant Escherichia coli strain which produced an inducible plasmid-encoded AmpC. ampD genes were amplified by PCR from strains of E. coli, Citrobacter freundii, and Pseudomonas aeruginosa. Also, carboxy-terminal truncations of C. freundii ampD genes were constructed representing deletions of 10, 21, or 25 codons. Amplified ampD products were cloned into pACYC184 containing inducible bla(ACT-1)-ampR. Plasmids were transformed into E. coli strains JRG582 (AmpD(-)) and K-12 259 (AmpD(+)). The strains were evaluated for a derepressed phenotype using ceftazidime MICs. Some mutated ampD genes, including the ampD gene of a derepressed C. freundii isolate, resulted in substantial decreases in ceftazidime MICs (from >256 microg/ml to 12 to 24 microg/ml) for the AmpD(-) strain, indicating no role for these mutations in derepressed phenotypes. However, ampD truncation products and ampD from a partially derepressed P. aeruginosa strain resulted in ceftazidime MICs of >256 microg/ml, indicating a role for these gene modifications in derepressed phenotypes. The use of this model system indicated that alternative mechanisms were involved in the derepressed phenotype observed in strains of C. freundii and P. aeruginosa. The alternative mechanism involved in the derepressed phenotype of the C. freundii isolate was downregulation of ampD transcription.
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Affiliation(s)
- Amber J Schmidtke
- Department of Medical Microbiology and Immunology, Creighton University, Omaha, NE 68178, USA
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D'Andrea MM, Nucleo E, Luzzaro F, Giani T, Migliavacca R, Vailati F, Kroumova V, Pagani L, Rossolini GM. CMY-16, a novel acquired AmpC-type beta-lactamase of the CMY/LAT lineage in multifocal monophyletic isolates of Proteus mirabilis from northern Italy. Antimicrob Agents Chemother 2006; 50:618-24. [PMID: 16436718 PMCID: PMC1366893 DOI: 10.1128/aac.50.2.618-624.2006] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We report multifocal detection (four different cities in northern Italy) of Proteus mirabilis isolates resistant to both oxyimino- and 7-alpha-methoxy-cephalosporins and producing a novel acquired AmpC-like beta-lactamase. The enzyme, named CMY-16, is a variant of the CMY/LAT lineage, which differs from the closest homologues, CMY-4 and CMY-12, by a single amino acid substitution (A171S or N363S, respectively) and from CMY-2 by two substitutions (A171S and W221R). Expression of the cloned bla(CMY-16) gene in Escherichia coli decreased susceptibility to penicillins, cephalosporins, and aztreonam. Tazobactam was more effective than clavulanate at antagonizing the enzyme activity. Genotyping, by random amplification of polymorphic DNA and pulsed-field gel electrophoresis of genomic DNA digested with SfiI, showed that isolates were clonally related to each other, although not identical. The bla(CMY-16) gene was not transferable to E. coli by conjugation or transformation. In all isolates, it was chromosomally located and inserted in a conserved genetic environment. PCR mapping experiments revealed that the bla(CMY-16) was flanked by ISEcp1 and the blc gene, similar to other genes of this lineage from plasmids of Salmonella enterica, Klebsiella spp., and E. coli. Overall, these results revealed multifocal spreading of a CMY-16-producing P. mirabilis clone in northern Italy. This finding represents the first report of an acquired AmpC-like beta-lactamase in Proteus mirabilis from Italy and underscores the emergence of similar resistance determinants in the European setting.
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Affiliation(s)
- Marco M D'Andrea
- Dipartimento di Biologia Molecolare, Laboratorio di Fisiologia e Biotecnologia dei Microrganismi, Università di Siena, I-53100 Siena, Italy
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Verdet C, Benzerara Y, Gautier V, Adam O, Ould-Hocine Z, Arlet G. Emergence of DHA-1-producing Klebsiella spp. in the Parisian region: genetic organization of the ampC and ampR genes originating from Morganella morganii. Antimicrob Agents Chemother 2006; 50:607-17. [PMID: 16436717 PMCID: PMC1366880 DOI: 10.1128/aac.50.2.607-617.2006] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Eleven Klebsiella pneumoniae clinical isolates and one Klebsiella oxytoca clinical isolate showing various pulsed-field gel electrophoresis types and producing an inducible DHA-1 class C beta-lactamase were isolated in the Parisian region between 1998 and 2003. The aim of this study was to compare the genetic organization of the bla(DHA-1) genes in this collection of clinical isolates. In four isolates, the Morganella morganii-derived genomic region containing bla(DHA-1) was inserted in an entire complex sul1-type integron, including a region common to In6-In7 (CR1), as previously described in a bla(DHA-1)-producing Salmonella enterica serovar Enteritidis KF92 isolate from Saudi Arabia in 1992. Different gene cassette arrays were characterized in each of these integrons. In two of them, an additional 10-kb fragment was inserted between the CR1 and the M. morganii-derived region and was similar to the sap (ABC transporter family) and psp (phage shock protein) operons originated from Salmonella enterica serovar Typhimurium. The length of the M. morganii region was variable, suggesting that several independent recombination events have occurred and that open reading frame orf513 encodes a recombinase involved in the mobilization of the resistance genes. The genetic organization of bla(DHA-1) was identical in the eight other isolates. This structure is likely derived from a complex integron following the insertion of IS26, leading to the deletion of the first part of integron. The horizontal transfer of one plasmid carrying that truncated integron was shown for seven of these isolates.
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Affiliation(s)
- Charlotte Verdet
- Service de Bactériologie, Hôpital Tenon, 4, rue de la Chine, Paris 75970 cedex, France
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Pournaras S, Ikonomidis A, Tzouvelekis LS, Tokatlidou D, Spanakis N, Maniatis AN, Legakis NJ, Tsakris A. VIM-12, a novel plasmid-mediated metallo-beta-lactamase from Klebsiella pneumoniae that resembles a VIM-1/VIM-2 hybrid. Antimicrob Agents Chemother 2006; 49:5153-6. [PMID: 16304191 PMCID: PMC1315972 DOI: 10.1128/aac.49.12.5153-5156.2005] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A transferable plasmid from Klebsiella pneumoniae carried a class 1 integron containing bla(VIM-12), a novel bla(VIM)-type gene, flanked by two copies of aacA7. bla(VIM-12) was clustered between bla(VIM-1) and bla(VIM-2) and differed from bla(VIM-1) by 18 nucleotides that were all located at the 3' end and matched the corresponding nucleotides in bla(VIM-2). The bla(VIM-12)-associated 59-base element was identical to that described in bla(VIM-2) alleles.
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Affiliation(s)
- Spyros Pournaras
- Department of Microbiology, Medical School, University of Thessaly, Larissa, Greece.
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Fournier PE, Vallenet D, Barbe V, Audic S, Ogata H, Poirel L, Richet H, Robert C, Mangenot S, Abergel C, Nordmann P, Weissenbach J, Raoult D, Claverie JM. Comparative genomics of multidrug resistance in Acinetobacter baumannii. PLoS Genet 2006; 2:e7. [PMID: 16415984 PMCID: PMC1326220 DOI: 10.1371/journal.pgen.0020007] [Citation(s) in RCA: 559] [Impact Index Per Article: 31.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2005] [Accepted: 12/06/2005] [Indexed: 02/06/2023] Open
Abstract
Acinetobacter baumannii is a species of nonfermentative gram-negative bacteria commonly found in water and soil. This organism was susceptible to most antibiotics in the 1970s. It has now become a major cause of hospital-acquired infections worldwide due to its remarkable propensity to rapidly acquire resistance determinants to a wide range of antibacterial agents. Here we use a comparative genomic approach to identify the complete repertoire of resistance genes exhibited by the multidrug-resistant A. baumannii strain AYE, which is epidemic in France, as well as to investigate the mechanisms of their acquisition by comparison with the fully susceptible A. baumannii strain SDF, which is associated with human body lice. The assembly of the whole shotgun genome sequences of the strains AYE and SDF gave an estimated size of 3.9 and 3.2 Mb, respectively. A. baumannii strain AYE exhibits an 86-kb genomic region termed a resistance island--the largest identified to date--in which 45 resistance genes are clustered. At the homologous location, the SDF strain exhibits a 20 kb-genomic island flanked by transposases but devoid of resistance markers. Such a switching genomic structure might be a hotspot that could explain the rapid acquisition of resistance markers under antimicrobial pressure. Sequence similarity and phylogenetic analyses confirm that most of the resistance genes found in the A. baumannii strain AYE have been recently acquired from bacteria of the genera Pseudomonas, Salmonella, or Escherichia. This study also resulted in the discovery of 19 new putative resistance genes. Whole-genome sequencing appears to be a fast and efficient approach to the exhaustive identification of resistance genes in epidemic infectious agents of clinical significance.
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Affiliation(s)
- Pierre-Edouard Fournier
- Information Génomique et Structurale, Institute for Structural Biology and Microbiology, IBSM, Marseille, France
- * To whom correspondence should be addressed. E-mail: (PEF); (JMC)
| | - David Vallenet
- Génoscope, Centre National de Séquençage and CNRS UMR8030, Evry, France
| | - Valérie Barbe
- Génoscope, Centre National de Séquençage and CNRS UMR8030, Evry, France
| | - Stéphane Audic
- Information Génomique et Structurale, Institute for Structural Biology and Microbiology, IBSM, Marseille, France
| | - Hiroyuki Ogata
- Information Génomique et Structurale, Institute for Structural Biology and Microbiology, IBSM, Marseille, France
| | - Laurent Poirel
- Département de Bactériologie-Virologie, Hôpital de Bicêtre, Le-Kremlin-Bicêtre, France
| | - Hervé Richet
- Unité des Rickettsies, CNRS UMR6020, Faculté de Médecine, Université de la Méditerranée, Marseille, France
| | - Catherine Robert
- Unité des Rickettsies, CNRS UMR6020, Faculté de Médecine, Université de la Méditerranée, Marseille, France
| | - Sophie Mangenot
- Génoscope, Centre National de Séquençage and CNRS UMR8030, Evry, France
| | - Chantal Abergel
- Information Génomique et Structurale, Institute for Structural Biology and Microbiology, IBSM, Marseille, France
| | - Patrice Nordmann
- Département de Bactériologie-Virologie, Hôpital de Bicêtre, Le-Kremlin-Bicêtre, France
| | - Jean Weissenbach
- Génoscope, Centre National de Séquençage and CNRS UMR8030, Evry, France
| | - Didier Raoult
- Unité des Rickettsies, CNRS UMR6020, Faculté de Médecine, Université de la Méditerranée, Marseille, France
| | - Jean-Michel Claverie
- Information Génomique et Structurale, Institute for Structural Biology and Microbiology, IBSM, Marseille, France
- * To whom correspondence should be addressed. E-mail: (PEF); (JMC)
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Giakkoupi P, Tambic-Andrasevic A, Vourli S, Skrlin J, Sestan-Crnek S, Tzouvelekis LS, Vatopoulos AC. Transferable DHA-1 cephalosporinase in Escherichia coli. Int J Antimicrob Agents 2005; 27:77-80. [PMID: 16352422 DOI: 10.1016/j.ijantimicag.2005.09.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2005] [Accepted: 09/15/2005] [Indexed: 10/25/2022]
Abstract
Three Escherichia coli isolates resistant to third-generation cephalosporins but negative for extended-spectrum beta-lactamase production were isolated from hospitalised patients in Zagreb, Croatia, during June 2003 to February 2004. Resistance was due to the inducible production of a DHA-1 cephalosporinase. Each isolate contained an integron-associated bla(DHA-1)-ampR sequence carried by similar-sized plasmids, of which one was self-transferable. Serotyping and polymerase chain reaction typing using ERIC2 primer indicated that the isolates were distinct. This is the first description of DHA beta-lactamase production in E. coli.
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Affiliation(s)
- P Giakkoupi
- Department of Microbiology, National School of Public Health, Athens, Greece
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Miriagou V, Carattoli A, Tzelepi E, Villa L, Tzouvelekis LS. IS26-associated In4-type integrons forming multiresistance loci in enterobacterial plasmids. Antimicrob Agents Chemother 2005; 49:3541-3. [PMID: 16048979 PMCID: PMC1196216 DOI: 10.1128/aac.49.8.3541-3543.2005] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Three distinct multiresistant loci from enterobacterial plasmids each comprised an integron and an IS26-associated sequence. Sequence comparison suggested a common ancestral structure that derived from an IS26 insertion into the 5' conserved segment of an In4-type integron and evolved through acquisition of gene cassettes and IS26-mediated recruitment of additional resistance genes of diverse origin.
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Affiliation(s)
- Vivi Miriagou
- Laboratory of Bacteriology, Hellenic Pasteur Institute, Vas. Sofias 127, Athens 11521, Greece.
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Kaneko K, Okamoto R, Nakano R, Kawakami S, Inoue M. Gene mutations responsible for overexpression of AmpC beta-lactamase in some clinical isolates of Enterobacter cloacae. J Clin Microbiol 2005; 43:2955-8. [PMID: 15956430 PMCID: PMC1151923 DOI: 10.1128/jcm.43.6.2955-2958.2005] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AmpC regulatory genes in 21 ceftazidime-resistant clinical isolates of Enterobacter cloacae (MICs of > or = 16 microg/ml) were characterized. All isolates exhibited AmpC overproduction due to AmpD mutation. Additionally, we found two AmpR mutants among the isolates. This is the first report of chromosomal ampR mutation in clinical isolates of E. cloacae.
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Affiliation(s)
- Kenichi Kaneko
- Department of Environmental Infectious Diseases, Graduate School of Medical Sciences, Kitasato University, 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555, Japan
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