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Afify FA, Shata AH, Aboelnaga N, Osama D, Elsayed SW, Saif NA, Mouftah SF, Shawky SM, Mohamed AA, Loay O, Elhadidy M. Emergence of carbapenem resistant gram-negative pathogens with high rate of colistin resistance in Egypt: A cross sectional study to assess resistance trends during the COVID-19 pandemic. J Genet Eng Biotechnol 2024; 22:100351. [PMID: 38494251 PMCID: PMC10980871 DOI: 10.1016/j.jgeb.2024.100351] [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: 11/21/2023] [Accepted: 11/22/2023] [Indexed: 03/19/2024]
Abstract
The current study investigated the temporal phenotypic and genotypic antimicrobial resistance (AMR) trends among multi-drug resistant and carbapenem-resistant Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa recovered from Egyptian clinical settings between 2020 and 2021. Bacterial identification and antimicrobial sensitivity of 111 clinical isolates against a panel of antibiotics were performed. Molecular screening for antibiotic resistance determinants along with integrons and associated gene cassettes was implemented. An alarming rate (98.2%) of these isolates were found to be phenotypically resistant to carbapenem. Although 23.9 % K. pneumoniae isolates were phenotypically resistant to colistin, no mobile colistin resistance (mcr) genes were detected. Among carbapenem-resistant isolates, blaNDM and blaOXA-48-like were the most prevalent genetic determinants and were significantly overrepresented among K. pneumoniae. Furthermore, 84.78% of K. pneumoniae isolates co-produced these two carbapenemase genes. The plasmid-mediated quinolone resistance genes (qnrS and qnrB) were detected among the bacterial species and were significantly more prevalent among K. pneumoniae. Moreover, Class 1 integron was detected in 82% of the bacterial isolates. This study alarmingly reveals elevated resistance to last-resort antibiotics such as carbapenems as well as colistin which impose a considerable burden in the health care settings in Egypt. Our future work will implement high throughput sequencing-based antimicrobial resistance surveillance analysis for characterization of novel AMR determinants. This information could be applied as a step forward to establish a robust antibiotic stewardship program in Egyptian clinical settings, thereby addressing the rising challenges of AMR.
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Affiliation(s)
- Fatma A Afify
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt; Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
| | - Ahmed H Shata
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt; Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
| | - Nirmeen Aboelnaga
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt; Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
| | - Dina Osama
- Department of Microbiology and Immunology, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA), Cairo, Egypt
| | - Salma W Elsayed
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt; Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt; Department of Microbiology & Immunology, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Nehal A Saif
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt; Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
| | - Shaimaa F Mouftah
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt
| | - Sherine M Shawky
- Department of Microbiology, Medical Research Institute, Alexandria University, Alexandria, Egypt
| | - Ahmed A Mohamed
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt; Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
| | - Omar Loay
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt; Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt
| | - Mohamed Elhadidy
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt; Center for Genomics, Helmy Institute for Medical Sciences, Zewail City of Science and Technology, Giza, Egypt; Department of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt.
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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: 3] [Impact Index Per Article: 3.0] [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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Celejewski-Marciniak P, Wolinowska R, Wróblewska M. Molecular Characterization of Class 1, 2 and 3 Integrons in Serratia spp. Clinical Isolates in Poland - Isolation of a New Plasmid and Identification of a Gene for a Novel Fusion Protein. Infect Drug Resist 2021; 14:4601-4610. [PMID: 34764657 PMCID: PMC8575446 DOI: 10.2147/idr.s325943] [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: 06/26/2021] [Accepted: 09/09/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose Gram-negative rods of the genus Serratia play an increasing role as etiological agents of healthcare-associated infections (HAI) in humans. These bacteria are characterized by natural and acquired resistance to several groups of antibacterial agents. The aim of the study was to characterize class 1, 2 and 3 integrons in the clinical isolates of Serratia spp. in Poland. Methods The study comprised 112 clinical strains of Serratia, isolated from patients hospitalized in Poland in 2010-2012. Identification of strains was confirmed using MALDI-TOF MS (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry) system. Detection of class 1, 2 and 3 integrase DNA sequence was performed by multiplex-PCR. Amplicons obtained in the PCR reactions were purified and then sequenced bidirectionally. Results Among the analyzed strains, Serratia marcescens was a predominant species (103/112, 92.0%). All three classes of integrase DNA sequence were detected in the analyzed strains of Serratia spp. DNA sequence of class 3 integron, besides integrase gene, revealed three gene cassettes (dfrB3, bla GES-7,bla OXA/aac(6')-Ib-cr). BLAST analysis of DNA sequence revealed that class 3 integron was carried on 9448 bp plasmid which was named pPCMI3 - whole sequence of its DNA was submitted to GenBank NCBI (National Center for Biotechnology Information) - NCBI MH569711. Conclusion In this study, we identified a new plasmid pPCMI3 harboring class 3 integron. This is the first report of a gene oxa/aac(6')-Ib-cr coding for a novel fusion protein, which consists of OXA β-lactamase and acetyltransferase aac(6')-Ib-cr. In the analyzed strains, class 1 and 2 integrons were also detected. Among the strains with class 1 integron, nine contained cassette array 5'CS-aadA2-ORF-dfrA12-3'CS, and two - cassette array 5'CS-aacC1-ORF-ORF-aadA1-3'CS, which were not previously reported in Serratia spp.
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Affiliation(s)
| | - Renata Wolinowska
- Department of Pharmaceutical Microbiology, Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
| | - Marta Wróblewska
- Department of Dental Microbiology, Medical University of Warsaw, Warsaw, Poland.,Department of Microbiology, Central Clinical Hospital, University Clinical Centre, Medical University of Warsaw, Warsaw, Poland
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Qian WD, Huang J, Zhang JN, Li XC, Kong Y, Wang T, Li YD. Antimicrobial and Antibiofilm Activities and Mechanism of Action of Chelerythrine Against Carbapenem-Resistant Serratia marcescens In Vitro. Microb Drug Resist 2021; 27:1105-1116. [PMID: 33439767 DOI: 10.1089/mdr.2020.0207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Aim: To evaluate the antimicrobial and antibiofilm effects of chelerythrine (CHE) against carbapenem-resistant Serratia marcescens (CRSM). Materials and Methods: The minimum inhibitory concentration (MIC) of CHE against CRSM was determined using the agar dilution method. Changes in intracellular adenosine triphosphate (ATP) concentration, intracellular pH, cell membrane potential, and cell membrane integrity were investigated to assess the influence of CHE on the cell membrane. The effects of CHE on cell morphology were observed by field emission scanning electron microscopy (FESEM) and transmission electron microscopy. The antibiofilm formation of CHE was measured by crystal violet staining and visualized with confocal laser scanning microscopy (CLSM) and FESEM. The influence of CHE on biofilm components was further investigated using CLSM specific combined with double-dyeing methods. Results: Our results showed that CHE had an MIC at 125 μg/mL against CRSM was capable of inhibiting the growth of CRSM and destroying its cell membrane integrity, as well as obviously changing the cell morphology. Sub-MIC CHE displayed robust inhibitory effects against CRSM biofilm formation by mediating the production of biofilm components. In addition, CLSM- and FESEM-mediated evaluation of the damage of biofilm cells and biofilm persistence revealed that at high concentrations, CHE could compromise the cells within biofilms and remove preformed biofilms. Conclusion: CHE shows promise as a natural antimicrobial substance against biofilm-positive CRSM, with the potential to serve as an alternative therapeutic agent.
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Affiliation(s)
- Wei-Dong Qian
- Department of Pharmacy, School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, P.R. China
| | - Jie Huang
- Department of Pharmacy, School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, P.R. China
| | - Jia-Ning Zhang
- Department of Pharmacy, School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, P.R. China
| | - Xin-Cheng Li
- Department of Pharmacy, School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, P.R. China
| | - Yi Kong
- Department of Clinical Laboratory Medicine, Jining First Peoples' Hospital, Jining, P.R. China
| | - Ting Wang
- Department of Pharmacy, School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, P.R. China
| | - Yong-Dong Li
- Ningbo Municipal Center for Disease Control and Prevention, Ningbo, P.R. China
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Sultan I, Rahman S, Jan AT, Siddiqui MT, Mondal AH, Haq QMR. Antibiotics, Resistome and Resistance Mechanisms: A Bacterial Perspective. Front Microbiol 2018; 9:2066. [PMID: 30298054 PMCID: PMC6160567 DOI: 10.3389/fmicb.2018.02066] [Citation(s) in RCA: 132] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 08/13/2018] [Indexed: 12/28/2022] Open
Abstract
History of mankind is regarded as struggle against infectious diseases. Rather than observing the withering away of bacterial diseases, antibiotic resistance has emerged as a serious global health concern. Medium of antibiotic resistance in bacteria varies greatly and comprises of target protection, target substitution, antibiotic detoxification and block of intracellular antibiotic accumulation. Further aggravation to prevailing situation arose on observing bacteria gradually becoming resistant to different classes of antibiotics through acquisition of resistance genes from same and different genera of bacteria. Attributing bacteria with feature of better adaptability, dispersal of antibiotic resistance genes to minimize effects of antibiotics by various means including horizontal gene transfer (conjugation, transformation, and transduction), Mobile genetic elements (plasmids, transposons, insertion sequences, integrons, and integrative-conjugative elements) and bacterial toxin-antitoxin system led to speedy bloom of antibiotic resistance amongst bacteria. Proficiency of bacteria to obtain resistance genes generated an unpleasant situation; a grave, but a lot unacknowledged, feature of resistance gene transfer.
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Affiliation(s)
- Insha Sultan
- Department of Biosciences, Jamia Millia Islamia, New Delhi, India
| | - Safikur Rahman
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, South Korea
| | - Arif Tasleem Jan
- School of Biosciences and Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, India
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Integrons in Enterobacteriaceae: diversity, distribution and epidemiology. Int J Antimicrob Agents 2017; 51:167-176. [PMID: 29038087 DOI: 10.1016/j.ijantimicag.2017.10.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 09/29/2017] [Accepted: 10/07/2017] [Indexed: 01/03/2023]
Abstract
Integrons are versatile gene acquisition systems that allow efficient capturing of exogenous genes and ensure their expression. Various classes of integrons possessing a wide variety of gene cassettes are ubiquitously distributed in enteric bacteria worldwide. The epidemiology of integrons associated multidrug resistance in Enterobacteriaceae is rapidly evolving. In the past two decades, the incidence of integrons in enteric bacteria has increased drastically with evolution of multiple gene cassettes, novel gene arrangements and complex chromosomal integrons such as Salmonella genomic islands. This review focuses on the distribution, versatility, spread and global trends of integrons among important members of the Enterobacteriaceae, including Escherichia coli, Klebsiella, Shigella and Salmonella, which are known to cause infections globally. Such a comprehensive understanding of integron-associated antibiotic resistance, their role in the spread of such resistance traits and their clinical relevance especially with regard to each genus individually is paramount to contain the global spread of antibiotic resistance.
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Deng Y, Bao X, Ji L, Chen L, Liu J, Miao J, Chen D, Bian H, Li Y, Yu G. Resistance integrons: class 1, 2 and 3 integrons. Ann Clin Microbiol Antimicrob 2015; 14:45. [PMID: 26487554 PMCID: PMC4618277 DOI: 10.1186/s12941-015-0100-6] [Citation(s) in RCA: 198] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 08/14/2015] [Indexed: 11/30/2022] Open
Abstract
As recently indiscriminate abuse of existing antibiotics in both clinical and veterinary treatment leads to proliferation of antibiotic resistance in microbes and poses a dilemma for the future treatment of such bacterial infection, antimicrobial resistance has been considered to be one of the currently leading concerns in global public health, and reported to widely spread and extended to a large variety of microorganisms. In China, as one of the currently worst areas for antibiotics abuse, the annual prescription of antibiotics, including both clinical and veterinary treatment, has approaching 140 gram per person and been roughly estimated to be 10 times higher than that in the United Kingdom, which is considered to be a potential area for the emergence of “Super Bugs”. Based on the integrons surveillance in Guangzhou, China in the past decade, this review thus aimed at summarizing the role of integrons in the perspective of both clinical setting and environment, with the focus on the occurrence and prevalence of class 1, 2 and 3 integrons.
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Affiliation(s)
- Yang Deng
- College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, 510640, China.
| | - Xuerui Bao
- College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, 510640, China.
| | - Lili Ji
- College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, 510640, China.
| | - Lei Chen
- Institute of Agro-products Processing, Anhui Academy of Agricultural Sciences, Hefei, 230031, China.
| | - Junyan Liu
- College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, 510640, China.
| | - Jian Miao
- College of Light Industry and Food Sciences, South China University of Technology, Guangzhou, 510640, China.
| | - Dingqiang Chen
- Department of Laboratory Medicine, First Affiliated Hospital of Guangzhou Medical College, Guangzhou, 510120, China.
| | - Huawei Bian
- The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510630, China.
| | - Yanmei Li
- Guangzhou Women and Children's Medical Center, 9 Jinsui Road, Guangzhou, 510620, China.
| | - Guangchao Yu
- First Affiliated Hospital of Jinan University, Guangzhou, 510620, China.
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Hsu JT, Chen CY, Young CW, Chao WL, Li MH, Liu YH, Lin CM, Ying C. Prevalence of sulfonamide-resistant bacteria, resistance genes and integron-associated horizontal gene transfer in natural water bodies and soils adjacent to a swine feedlot in northern Taiwan. JOURNAL OF HAZARDOUS MATERIALS 2014; 277:34-43. [PMID: 24637153 DOI: 10.1016/j.jhazmat.2014.02.016] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 02/06/2014] [Accepted: 02/11/2014] [Indexed: 05/10/2023]
Abstract
Antibiotics are commonly used in swine feed to treat and prevent disease, as well as to promote growth. Antibiotics released into the environment via wastewater could accelerate the emergence of antibiotic-resistant bacteria and resistance genes in the surrounding environment. In this study, we quantified the occurrence of sulfonamides, sulfonamide-resistant microorganisms and resistance genes in the wastewater from a swine farm in northern Taiwan and its surrounding natural water bodies and soils. Sulfonamide levels were similar in the receiving downstream and upstream river water. However, the prevalence of sulfonamide-resistant bacteria and resistance genes, as analyzed by cultivation-dependent and -independent molecular approaches, was significantly greater in the downstream compared to the upstream river water samples. Barcoded-pyrosequencing revealed a highly diverse bacterial community structure in each sample. However, the sequence identity of the sulfonamide resistance gene sul1 in the wastewater and downstream environment samples was nearly identical (99-100%). The sul1 gene, which is genetically linked to class 1 integrons, was dominant in the downstream water bodies and soils. In conclusion, the increased prevalence of sulfonamide resistance genes in the wastewater from a swine farm, independent of the persistent presence of sulfonamides, could be a potential source of resistant gene pools in the surrounding environment.
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Affiliation(s)
- Jih-Tay Hsu
- Department of Animal Sciences, National Taiwan University, Taipei, Taiwan, ROC
| | - Chia-Yang Chen
- Institute of Environmental Health, National Taiwan University, Taipei, Taiwan, ROC
| | - Chu-Wen Young
- Department of Microbiology, Soochow University, Taipei, Taiwan, ROC
| | - Wei-Liang Chao
- Department of Microbiology, Soochow University, Taipei, Taiwan, ROC
| | - Mao-Hao Li
- Department of Microbiology, Soochow University, Taipei, Taiwan, ROC
| | - Yung-Hsin Liu
- Department of Microbiology, Soochow University, Taipei, Taiwan, ROC
| | - Chu-Ming Lin
- Department of Microbiology, Soochow University, Taipei, Taiwan, ROC
| | - Chingwen Ying
- Department of Microbiology, Soochow University, Taipei, Taiwan, ROC.
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Emergence of resistance to antibacterial agents: the role of quaternary ammonium compounds--a critical review. Int J Antimicrob Agents 2012; 39:381-9. [PMID: 22421329 DOI: 10.1016/j.ijantimicag.2012.01.011] [Citation(s) in RCA: 343] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 01/12/2012] [Indexed: 12/11/2022]
Abstract
Quaternary ammonium compounds (QACs) are widely distributed in hospitals, industry and cosmetics. Little attention has been focused on the potential impact of QACs on the emergence of antibiotic resistance in patients and the environment. To assess this issue, we conducted a literature review on QAC chemical structure, fields of application, mechanism of action, susceptibility testing, prevalence, and co- or cross-resistance to antibiotics. Special attention was paid to the effects of QACs on microflora; in particular, the issue of the potential of QACs for applying selective pressure on multiple-antibiotic-resistant organisms was raised. It was found that there is a lack of standardised procedures for interpreting susceptibility test results. QACs have different impacts on the minimum inhibitory concentrations of antibacterials depending on the antibacterial compound investigated, the resistance genes involved, the measuring methodology and the interpretative criteria. The unmet needs for adequate detection of reduced susceptibility to QACs and antibiotics include (i) a consensus definition for resistance, (ii) epidemiological cut-off values and (iii) clinical resistance breakpoints. This review advocates the design of international guidelines for QAC use.
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Zhang XX, Zhang T, Zhang M, Fang HHP, Cheng SP. Characterization and quantification of class 1 integrons and associated gene cassettes in sewage treatment plants. Appl Microbiol Biotechnol 2009; 82:1169-77. [PMID: 19224208 DOI: 10.1007/s00253-009-1886-y] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2008] [Revised: 01/18/2009] [Accepted: 01/20/2009] [Indexed: 10/21/2022]
Abstract
Class 1 integrons and gene cassettes containing antibiotic resistance genes (ARGs) in five different sewage treatment plants (STPs) were characterized and quantified using polymerase chain reaction (PCR), sequencing, and quantitative real-time PCR (qRT-PCR) in this study. Class 1 integronase gene (intI1) was found commonly occurring in all of activated sludge samples from the five STPs, as well as in influent and effluent of two STPs at Hong Kong. One hundred and nine lactose-fermenting Enterobacteriaceae (LFE) strains were isolated from activated sludge of Shatin STP. Among them, 36 strains (33.0%) were found to carry class 1 integrons. PCR assays showed that 11 of the 36 intI1-carrying isolates harbored a common type of gene cassette array of about 1,600 bps, as well as the static genes (sulI and qacEDelta1) on class 1 integrons. This gene cassette array was found phylogenetically close to antibiotic resistance genes dfr17 and aadA5, encoding dihydrofolate reductase conferring resistance to trimethoprim and adenylyltransferase conferring resistance to spectinomycin/streptomycin, respectively. Antimicrobial susceptibility analysis demonstrated that all the 11 LFEs carrying gene cassette were multi-resistant, especially having common resistance to trimethoprim and streptomycin. qRT-PCR assay showed that genes copies of both class 1 integron and the gene cassette varied significantly among the activated sludge sampled from different STPs, at different time points or different treatment steps. More than 90% of class 1 integrons and the gene cassette were removed by activated sludge processes in two STPs, while the disinfection process removed 94% integron and 77% gene cassette in one STP.
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Affiliation(s)
- Xu-Xiang Zhang
- Environmental Biotechnology Lab, Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR, China
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11
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Zhang XX, Zhang T, Fang HHP. Antibiotic resistance genes in water environment. Appl Microbiol Biotechnol 2009; 82:397-414. [PMID: 19130050 DOI: 10.1007/s00253-008-1829-z] [Citation(s) in RCA: 558] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2008] [Revised: 12/11/2008] [Accepted: 12/13/2008] [Indexed: 12/30/2022]
Abstract
The use of antibiotics may accelerate the development of antibiotic resistance genes (ARGs) and bacteria which shade health risks to humans and animals. The emerging of ARGs in the water environment is becoming an increasing worldwide concern. Hundreds of various ARGs encoding resistance to a broad range of antibiotics have been found in microorganisms distributed not only in hospital wastewaters and animal production wastewaters, but also in sewage, wastewater treatment plants, surface water, groundwater, and even in drinking water. This review summarizes recently published information on the types, distributions, and horizontal transfer of ARGs in various aquatic environments, as well as the molecular methods used to detect environmental ARGs, including specific and multiplex PCR (polymerase chain reaction), real-time PCR, DNA sequencing, and hybridization based techniques.
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Affiliation(s)
- Xu-Xiang Zhang
- Environmental Biotechnology Lab,Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR, China
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