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Bhat BA, Mir RA, Qadri H, Dhiman R, Almilaibary A, Alkhanani M, Mir MA. Integrons in the development of antimicrobial resistance: critical review and perspectives. Front Microbiol 2023; 14:1231938. [PMID: 37720149 PMCID: PMC10500605 DOI: 10.3389/fmicb.2023.1231938] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 08/14/2023] [Indexed: 09/19/2023] Open
Abstract
Antibiotic resistance development and pathogen cross-dissemination are both considered essential risks to human health on a worldwide scale. Antimicrobial resistance genes (AMRs) are acquired, expressed, disseminated, and traded mainly through integrons, the key players capable of transferring genes from bacterial chromosomes to plasmids and their integration by integrase to the target pathogenic host. Moreover, integrons play a central role in disseminating and assembling genes connected with antibiotic resistance in pathogenic and commensal bacterial species. They exhibit a large and concealed diversity in the natural environment, raising concerns about their potential for comprehensive application in bacterial adaptation. They should be viewed as a dangerous pool of resistance determinants from the "One Health approach." Among the three documented classes of integrons reported viz., class-1, 2, and 3, class 1 has been found frequently associated with AMRs in humans and is a critical genetic element to serve as a target for therapeutics to AMRs through gene silencing or combinatorial therapies. The direct method of screening gene cassettes linked to pathogenesis and resistance harbored by integrons is a novel way to assess human health. In the last decade, they have witnessed surveying the integron-associated gene cassettes associated with increased drug tolerance and rising pathogenicity of human pathogenic microbes. Consequently, we aimed to unravel the structure and functions of integrons and their integration mechanism by understanding horizontal gene transfer from one trophic group to another. Many updates for the gene cassettes harbored by integrons related to resistance and pathogenicity are extensively explored. Additionally, an updated account of the assessment of AMRs and prevailing antibiotic resistance by integrons in humans is grossly detailed-lastly, the estimation of AMR dissemination by employing integrons as potential biomarkers are also highlighted. The current review on integrons will pave the way to clinical understanding for devising a roadmap solution to AMR and pathogenicity. Graphical AbstractThe graphical abstract displays how integron-aided AMRs to humans: Transposons capture integron gene cassettes to yield high mobility integrons that target res sites of plasmids. These plasmids, in turn, promote the mobility of acquired integrons into diverse bacterial species. The acquisitions of resistant genes are transferred to humans through horizontal gene transfer.
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Affiliation(s)
- Basharat Ahmad Bhat
- Department of Bio-Resources, School of Biological Sciences, University of Kashmir, Srinagar, India
| | - Rakeeb Ahmad Mir
- Department of Biotechnology, School of Life Sciences, Central University of Kashmir, Ganderbal, India
| | - Hafsa Qadri
- Department of Bio-Resources, School of Biological Sciences, University of Kashmir, Srinagar, India
| | - Rohan Dhiman
- Department of Life Sciences, National Institute of Technology (NIT), Rourkela, Odisha, India
| | - Abdullah Almilaibary
- Department of Family and Community Medicine, Faculty of Medicine, Al Baha University, Al Bahah, Saudi Arabia
| | - Mustfa Alkhanani
- Department of Biology, College of Science, Hafr Al Batin University of Hafr Al-Batin, Hafar Al Batin, Saudi Arabia
| | - Manzoor Ahmad Mir
- Department of Bio-Resources, School of Biological Sciences, University of Kashmir, Srinagar, India
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Barbu IC, Gheorghe-Barbu I, Grigore GA, Vrancianu CO, Chifiriuc MC. Antimicrobial Resistance in Romania: Updates on Gram-Negative ESCAPE Pathogens in the Clinical, Veterinary, and Aquatic Sectors. Int J Mol Sci 2023; 24:7892. [PMID: 37175597 PMCID: PMC10178704 DOI: 10.3390/ijms24097892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/15/2023] Open
Abstract
Multidrug-resistant Gram-negative bacteria such as Acinetobacter baumannii, Pseudomonas aeruginosa, and members of the Enterobacterales order are a challenging multi-sectorial and global threat, being listed by the WHO in the priority list of pathogens requiring the urgent discovery and development of therapeutic strategies. We present here an overview of the antibiotic resistance profiles and epidemiology of Gram-negative pathogens listed in the ESCAPE group circulating in Romania. The review starts with a discussion of the mechanisms and clinical significance of Gram-negative bacteria, the most frequent genetic determinants of resistance, and then summarizes and discusses the epidemiological studies reported for A. baumannii, P. aeruginosa, and Enterobacterales-resistant strains circulating in Romania, both in hospital and veterinary settings and mirrored in the aquatic environment. The Romanian landscape of Gram-negative pathogens included in the ESCAPE list reveals that all significant, clinically relevant, globally spread antibiotic resistance genes and carrying platforms are well established in different geographical areas of Romania and have already been disseminated beyond clinical settings.
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Affiliation(s)
- Ilda Czobor Barbu
- Microbiology-Immunology Department, Faculty of Biology, University of Bucharest, 050095 Bucharest, Romania
- The Research Institute of the University of Bucharest, 050095 Bucharest, Romania
| | - Irina Gheorghe-Barbu
- Microbiology-Immunology Department, Faculty of Biology, University of Bucharest, 050095 Bucharest, Romania
- The Research Institute of the University of Bucharest, 050095 Bucharest, Romania
| | - Georgiana Alexandra Grigore
- Microbiology-Immunology Department, Faculty of Biology, University of Bucharest, 050095 Bucharest, Romania
- The Research Institute of the University of Bucharest, 050095 Bucharest, Romania
- National Institute of Research and Development for Biological Sciences, 060031 Bucharest, Romania
| | - Corneliu Ovidiu Vrancianu
- Microbiology-Immunology Department, Faculty of Biology, University of Bucharest, 050095 Bucharest, Romania
- The Research Institute of the University of Bucharest, 050095 Bucharest, Romania
| | - Mariana Carmen Chifiriuc
- Microbiology-Immunology Department, Faculty of Biology, University of Bucharest, 050095 Bucharest, Romania
- The Research Institute of the University of Bucharest, 050095 Bucharest, Romania
- Academy of Romanian Scientists, 050044 Bucharest, Romania
- Romanian Academy, 010071 Bucharest, Romania
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Ghaly TM, Tetu SG, Penesyan A, Qi Q, Rajabal V, Gillings MR. Discovery of integrons in Archaea: Platforms for cross-domain gene transfer. SCIENCE ADVANCES 2022; 8:eabq6376. [PMID: 36383678 PMCID: PMC9668308 DOI: 10.1126/sciadv.abq6376] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 10/19/2022] [Indexed: 06/16/2023]
Abstract
Horizontal gene transfer between different domains of life is increasingly being recognized as an important evolutionary driver, with the potential to increase the pace of biochemical innovation and environmental adaptation. However, the mechanisms underlying the recruitment of exogenous genes from foreign domains are mostly unknown. Integrons are a family of genetic elements that facilitate this process within Bacteria. However, they have not been reported outside Bacteria, and thus their potential role in cross-domain gene transfer has not been investigated. Here, we discover that integrons are also present in 75 archaeal metagenome-assembled genomes from nine phyla, and are particularly enriched among Asgard archaea. Furthermore, we provide experimental evidence that integrons can facilitate the recruitment of archaeal genes by bacteria. Our findings establish a previously unknown mechanism of cross-domain gene transfer whereby bacteria can incorporate archaeal genes from their surrounding environment via integron activity. These findings have important implications for prokaryotic ecology and evolution.
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Affiliation(s)
- Timothy M. Ghaly
- School of Natural Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Sasha G. Tetu
- School of Natural Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Anahit Penesyan
- School of Natural Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Qin Qi
- School of Natural Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Vaheesan Rajabal
- School of Natural Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Michael R. Gillings
- School of Natural Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
- ARC Centre of Excellence in Synthetic Biology, Macquarie University, Sydney, New South Wales 2109, Australia
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Ayala Nuñez T, Cerbino GN, Rapisardi MF, Quiroga C, Centrón D. Novel Mobile Integrons and Strain-Specific Integrase Genes within Shewanella spp. Unveil Multiple Lateral Genetic Transfer Events within The Genus. Microorganisms 2022; 10:microorganisms10061102. [PMID: 35744620 PMCID: PMC9229058 DOI: 10.3390/microorganisms10061102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 04/28/2022] [Accepted: 04/29/2022] [Indexed: 11/16/2022] Open
Abstract
Shewanella spp. are Gram-negative bacteria that thrive in aquatic niches and also can cause infectious diseases as opportunistic pathogens. Chromosomal (CI) and mobile integrons (MI) were previously described in some Shewanella isolates. Here, we evaluated the occurrence of integrase genes, the integron systems and their genetic surroundings in the genus. We identified 22 integrase gene types, 17 of which were newly described, showing traits of multiple events of lateral genetic transfer (LGT). Phylogenetic analysis showed that most of them were strain-specific, except for Shewanella algae, where SonIntIA-like may have co-evolved within the host as typical CIs. It is noteworthy that co-existence of up to five different integrase genes within a strain, as well as their wide dissemination to Alteromonadales, Vibrionales, Chromatiales, Oceanospirillales and Enterobacterales was observed. In addition, identification of two novel MIs suggests that continuous LGT events may have occurred resembling the behavior of class 1 integrons. The constant emergence of determinants associated to antimicrobial resistance worldwide, concomitantly with novel MIs in strains capable to harbor several types of integrons, may be an alarming threat for the recruitment of novel antimicrobial resistance gene cassettes in the genus Shewanella, with its consequent contribution towards multidrug resistance in clinical isolates.
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Affiliation(s)
- Teolincacihuatl Ayala Nuñez
- Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM, UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires CP1121, Argentina; (T.A.N.); (G.N.C.); (M.F.R.)
| | - Gabriela N. Cerbino
- Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM, UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires CP1121, Argentina; (T.A.N.); (G.N.C.); (M.F.R.)
| | - María Florencia Rapisardi
- Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM, UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires CP1121, Argentina; (T.A.N.); (G.N.C.); (M.F.R.)
| | - Cecilia Quiroga
- Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM, UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires CP1121, Argentina; (T.A.N.); (G.N.C.); (M.F.R.)
- Laboratorio de Investigación en Biología del ARN Bacteriano IMPaM (UBA/CONICET), Faculty of Medicine, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires CP1121, Argentina
- Correspondence: or (C.Q.); (D.C.); Tel.: +54-11-5285-3500 (C.Q.); +54-911-50987496 (D.C.)
| | - Daniela Centrón
- Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM, UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires CP1121, Argentina; (T.A.N.); (G.N.C.); (M.F.R.)
- Laboratorio de Investigaciones en Mecanismos de Resistencia a Antibióticos IMPaM (UBA/CONICET), Faculty of Medicine, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires CP1121, Argentina
- Correspondence: or (C.Q.); (D.C.); Tel.: +54-11-5285-3500 (C.Q.); +54-911-50987496 (D.C.)
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Integron gene cassettes harboring novel variants of D-alanine-D-alanine ligase confer high-level resistance to D-cycloserine. Sci Rep 2020; 10:20709. [PMID: 33244063 PMCID: PMC7691350 DOI: 10.1038/s41598-020-77377-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 11/10/2020] [Indexed: 11/08/2022] Open
Abstract
Antibiotic resistance poses an increasing threat to global health. To tackle this problem, the identification of principal reservoirs of antibiotic resistance genes (ARGs) plus an understanding of drivers for their evolutionary selection are important. During a PCR-based screen of ARGs associated with integrons in saliva-derived metagenomic DNA of healthy human volunteers, two novel variants of genes encoding a d-alanine-d-alanine ligase (ddl6 and ddl7) located within gene cassettes in the first position of a reverse integron were identified. Treponema denticola was identified as the likely host of the ddl cassettes. Both ddl6 and ddl7 conferred high level resistance to d-cycloserine when expressed in Escherichia coli with ddl7 conferring four-fold higher resistance to D-cycloserine compared to ddl6. A SNP was found to be responsible for this difference in resistance phenotype between the two ddl variants. Molecular dynamics simulations were used to explain the mechanism of this phenotypic change at the atomic scale. A hypothesis for the evolutionary selection of ddl containing integron gene cassettes is proposed, based on molecular docking of plant metabolites within the ATP and d-cycloserine binding pockets of Ddl.
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Ali N, Lin Y, Qing Z, Xiao D, Ud Din A, Ali I, Lian T, Chen B, Wen R. The Role of Agriculture in the Dissemination of Class 1 Integrons, Antimicrobial Resistance, and Diversity of Their Gene Cassettes in Southern China. Genes (Basel) 2020; 11:genes11091014. [PMID: 32872161 PMCID: PMC7564866 DOI: 10.3390/genes11091014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 08/21/2020] [Accepted: 08/26/2020] [Indexed: 12/15/2022] Open
Abstract
Integrons are hot spots for acquiring gene cassettes from the environment and play a major role in the bacterial evolution and dissemination of antimicrobial resistance (AMR), thus posing a serious threat. There are currently studies on integrons and antibiotic resistance genes; however, the presence and association of integrons in different agricultural crops and their subsequent dissemination and role in AMR have not been reported previously. This study examines the abundance of integrons, their gene cassette diversity in various crop soils, and their role in the dissemination of AMR in the southern region of China. Samples from different agri-crop soil, such as rice (R.S), sugarcane (S.S), citrus (C.S), banana (B.S), agricultural runoff (the point where the runoff of all sites meet (R.O)), and wild (non-agricultural) soil (W.S), were collected. Quantitative PCR was used to determine the abundance of integrons, and clone libraries were constructed to examine the gene cassette arrays. All the tested samples were found positive for Class-I (CL1) integrons and revealed a higher concentration and higher relative abundance of R.S than the others, with the least found at the W.S site. The W.S CL1 cassette arrays were found empty, and no putative conserved domains were found. The R.O was found to contain a high number of gene cassettes with various functions, while the smallest number of gene cassettes was found in the S.S among the crop soils. Most of the gene cassettes presented by the R.O were primarily shared with other sites, and the antibiotic-resistant genes were consistently observed to be dominant. The constructed clone libraries represented a diverse gene cassette array with 16% novel gene cassettes that play a vital role in pathogenesis, transportation, biosynthesis, and AMR. Most resistance-related gene cassettes were associated with the genes encoding resistance to quaternary ammonium compound (QAC) and aminoglycosides. This study highlights the significant differences in the abundance of integrons among various agricultural soils and offers deep insight into the pools of gene cassettes that play a key role in the dissemination of integrons and AMR.
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Affiliation(s)
- Niyaz Ali
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bio-Resources, College of Life Science and Technology, Guangxi University, Nanning 530004, China; (N.A.); (Y.L.); (Z.Q.); (D.X.); (I.A.); (B.C.)
| | - Yinfu Lin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bio-Resources, College of Life Science and Technology, Guangxi University, Nanning 530004, China; (N.A.); (Y.L.); (Z.Q.); (D.X.); (I.A.); (B.C.)
| | - Zhen Qing
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bio-Resources, College of Life Science and Technology, Guangxi University, Nanning 530004, China; (N.A.); (Y.L.); (Z.Q.); (D.X.); (I.A.); (B.C.)
| | - Dan Xiao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bio-Resources, College of Life Science and Technology, Guangxi University, Nanning 530004, China; (N.A.); (Y.L.); (Z.Q.); (D.X.); (I.A.); (B.C.)
| | - Ahmad Ud Din
- Drug Discovery Research Center, South West Medical University, Luzhou 646000, China;
| | - Izhar Ali
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bio-Resources, College of Life Science and Technology, Guangxi University, Nanning 530004, China; (N.A.); (Y.L.); (Z.Q.); (D.X.); (I.A.); (B.C.)
| | - Tengxiang Lian
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bio-Resources, South China Agricultural University, Guangzhou 510642, China;
| | - Baoshan Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bio-Resources, College of Life Science and Technology, Guangxi University, Nanning 530004, China; (N.A.); (Y.L.); (Z.Q.); (D.X.); (I.A.); (B.C.)
- Guangxi Key Lab for Sugarcane Biology, College of Agriculture, Guangxi University, Nanning 530004, China
| | - Ronghui Wen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bio-Resources, College of Life Science and Technology, Guangxi University, Nanning 530004, China; (N.A.); (Y.L.); (Z.Q.); (D.X.); (I.A.); (B.C.)
- Correspondence: ; Tel.: +86-13669614062
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Tansirichaiya S, Mullany P, Roberts AP. Promoter activity of ORF-less gene cassettes isolated from the oral metagenome. Sci Rep 2019; 9:8388. [PMID: 31182805 PMCID: PMC6557892 DOI: 10.1038/s41598-019-44640-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 05/17/2019] [Indexed: 01/09/2023] Open
Abstract
Integrons are genetic elements consisting of a functional platform for recombination and expression of gene cassettes (GCs). GCs usually carry promoter-less open reading frames (ORFs), encoding proteins with various functions including antibiotic resistance. The transcription of GCs relies mainly on a cassette promoter (PC), located upstream of an array of GCs. Some integron GCs, called ORF-less GCs, contain no identifiable ORF with a small number shown to be involved in antisense mRNA mediated gene regulation. In this study, the promoter activity of ORF-less GCs, previously recovered from the oral metagenome, was verified by cloning them upstream of a gusA reporter, proving they can function as a promoter, presumably allowing bacteria to adapt to multiple stresses within the complex physico-chemical environment of the human oral cavity. A bi-directional promoter detection system was also developed allowing direct identification of clones with promoter-containing GCs on agar plates. Novel promoter-containing GCs were identified from the human oral metagenomic DNA using this construct, called pBiDiPD. This is the first demonstration and detection of promoter activity of ORF-less GCs from Treponema bacteria and the development of an agar plate-based detection system will enable similar studies in other environments.
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Affiliation(s)
- Supathep Tansirichaiya
- Department of Microbial Diseases, University College London, Eastman Dental Institute, 256 Gray's Inn Road, London, WC1X 8LD, UK.,Department of Clinical Dentistry, Faculty of Health Sciences, UiT the Arctic University of Norway, Tromsø, Norway
| | - Peter Mullany
- Department of Microbial Diseases, University College London, Eastman Dental Institute, 256 Gray's Inn Road, London, WC1X 8LD, UK
| | - Adam P Roberts
- Department of Microbial Diseases, University College London, Eastman Dental Institute, 256 Gray's Inn Road, London, WC1X 8LD, UK. .,Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
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Detection of Novel Integrons in the Metagenome of Human Saliva. PLoS One 2016; 11:e0157605. [PMID: 27304457 PMCID: PMC4909258 DOI: 10.1371/journal.pone.0157605] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 06/01/2016] [Indexed: 01/08/2023] Open
Abstract
Integrons are genetic elements capable of capturing and expressing open reading frames (ORFs) embedded within gene cassettes. They are involved in the dissemination of antibiotic resistance genes (ARGs) in clinically important pathogens. Although the ARGs are common in the oral cavity the association of integrons and antibiotic resistance has not been reported there. In this work, a PCR-based approach was used to investigate the presence of integrons and associated gene cassettes in human oral metagenomic DNA obtained from both the UK and Bangladesh. We identified a diverse array of gene cassettes containing ORFs predicted to confer antimicrobial resistance and other adaptive traits. The predicted proteins include a putative streptogramin A O-acetyltransferase, a bleomycin binding protein, cof-like hydrolase, competence and motility related proteins. This is the first study detecting integron gene cassettes directly from oral metagenomic DNA samples. The predicted proteins are likely to carry out a multitude of functions; however, the function of the majority is yet unknown.
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Abstract
Integrons are versatile gene acquisition systems commonly found in bacterial genomes. They are ancient elements that are a hot spot for genomic complexity, generating phenotypic diversity and shaping adaptive responses. In recent times, they have had a major role in the acquisition, expression, and dissemination of antibiotic resistance genes. Assessing the ongoing threats posed by integrons requires an understanding of their origins and evolutionary history. This review examines the functions and activities of integrons before the antibiotic era. It shows how antibiotic use selected particular integrons from among the environmental pool of these elements, such that integrons carrying resistance genes are now present in the majority of Gram-negative pathogens. Finally, it examines the potential consequences of widespread pollution with the novel integrons that have been assembled via the agency of human antibiotic use and speculates on the potential uses of integrons as platforms for biotechnology.
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Gillings MR, Gaze WH, Pruden A, Smalla K, Tiedje JM, Zhu YG. Using the class 1 integron-integrase gene as a proxy for anthropogenic pollution. ISME JOURNAL 2014; 9:1269-79. [PMID: 25500508 PMCID: PMC4438328 DOI: 10.1038/ismej.2014.226] [Citation(s) in RCA: 807] [Impact Index Per Article: 80.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2014] [Revised: 09/18/2014] [Accepted: 10/23/2014] [Indexed: 12/14/2022]
Abstract
Around all human activity, there are zones of pollution with pesticides, heavy metals, pharmaceuticals, personal care products and the microorganisms associated with human waste streams and agriculture. This diversity of pollutants, whose concentration varies spatially and temporally, is a major challenge for monitoring. Here, we suggest that the relative abundance of the clinical class 1 integron-integrase gene, intI1, is a good proxy for pollution because: (1) intI1 is linked to genes conferring resistance to antibiotics, disinfectants and heavy metals; (2) it is found in a wide variety of pathogenic and nonpathogenic bacteria; (3) its abundance can change rapidly because its host cells can have rapid generation times and it can move between bacteria by horizontal gene transfer; and (4) a single DNA sequence variant of intI1 is now found on a wide diversity of xenogenetic elements, these being complex mosaic DNA elements fixed through the agency of human selection. Here we review the literature examining the relationship between anthropogenic impacts and the abundance of intI1, and outline an approach by which intI1 could serve as a proxy for anthropogenic pollution.
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Affiliation(s)
- Michael R Gillings
- Department of Biological Sciences, Genes to Geoscience Research Centre, Macquarie University, Sydney, New South Wales, Australia
| | - William H Gaze
- European Centre for Environment and Human Health, University of Exeter Medical School, Royal Cornwall Hospital, Truro, UK
| | - Amy Pruden
- Via Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA
| | - Kornelia Smalla
- Institute for Epidemiology and Pathogen Diagnostics, Julius Kühn-Institut, Federal Research Centre for Cultivated Plants, Braunschweig, Germany
| | - James M Tiedje
- Center for Microbial Ecology, Michigan State University, East Lansing, MI, USA
| | - Yong-Guan Zhu
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
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