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Huang J, Xiao J, Wang X, Xue X, Ma Y, Zhang Z, Zheng L, Zafir M, Liu P, Zhao X, Larsen AR, Xue H. Unearthing New ccr Genes and Staphylococcal Cassette Chromosome Elements in Staphylococci Through Genome Mining. J Infect Dis 2024; 230:231-238. [PMID: 39052728 DOI: 10.1093/infdis/jiae044] [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: 08/18/2023] [Revised: 01/12/2024] [Accepted: 01/24/2024] [Indexed: 01/27/2024] Open
Abstract
Staphylococcal cassette chromosome mec (SCCmec) typing is crucial for investigating methicillin-resistant Staphylococcus aureus (MRSA), relying primarily on the combination of ccr and mec gene complexes. To date, 19 ccr genes and 10 ccr gene complexes have been identified, forming 15 SCCmec types. With the vast release of bacterial genome sequences, mining the database for novel ccr gene complexes and SCC/SCCmec elements could enhance MRSA epidemiological studies. In this study, we identified 12 novel ccr genes (6 ccrA, 3 ccrB, and 3 ccrC) through mining of the National Center for Biotechnology Information (NCBI) database, forming 12 novel ccr gene complexes and 10 novel SCC elements. Overexpression of 5 groups of novel Ccr recombinases (CcrA9B3, CcrA10B1, CcrC3, CcrC4, and CcrC5) in a mutant MRSA strain lacking the ccr gene and extrachromosomal circular intermediate (ciSCC) production significantly promoted ciSCC production, demonstrating their biological activity. This discovery provides an opportunity to advance MRSA epidemiological research and develop database-based bacterial typing methods.
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Affiliation(s)
- Jianguo Huang
- College of Animal Science and Technology, Northwest Agricultural and Forestry University, Yangling, Shaanxi, People's Republic of China
| | - Jinhe Xiao
- College of Animal Science and Technology, Northwest Agricultural and Forestry University, Yangling, Shaanxi, People's Republic of China
| | - Xiaokun Wang
- College of Animal Science and Technology, Northwest Agricultural and Forestry University, Yangling, Shaanxi, People's Republic of China
| | - Xuemei Xue
- College of Animal Science and Technology, Northwest Agricultural and Forestry University, Yangling, Shaanxi, People's Republic of China
| | - Yadong Ma
- College of Animal Science and Technology, Northwest Agricultural and Forestry University, Yangling, Shaanxi, People's Republic of China
| | - Ziqian Zhang
- College of Animal Science and Technology, Northwest Agricultural and Forestry University, Yangling, Shaanxi, People's Republic of China
| | - Liangjun Zheng
- College of Animal Science and Technology, Northwest Agricultural and Forestry University, Yangling, Shaanxi, People's Republic of China
| | - Muhammad Zafir
- College of Animal Science and Technology, Northwest Agricultural and Forestry University, Yangling, Shaanxi, People's Republic of China
| | - Pilong Liu
- College of Animal Science and Technology, Northwest Agricultural and Forestry University, Yangling, Shaanxi, People's Republic of China
| | - Xin Zhao
- Department of Animal Science, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Anders Rhod Larsen
- Department of Bacteria, Parasites, and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Huping Xue
- College of Animal Science and Technology, Northwest Agricultural and Forestry University, Yangling, Shaanxi, People's Republic of China
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2
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Chowdhury AR, Mukherjee D, Chatterjee R, Chakravortty D. Defying the odds: Determinants of the antimicrobial response of Salmonella Typhi and their interplay. Mol Microbiol 2024; 121:213-229. [PMID: 38071466 DOI: 10.1111/mmi.15209] [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: 07/31/2023] [Revised: 11/12/2023] [Accepted: 11/27/2023] [Indexed: 02/12/2024]
Abstract
Salmonella Typhi, the invasive serovar of S. enterica subspecies enterica, causes typhoid fever in healthy human hosts. The emergence of antibiotic-resistant strains has consistently challenged the successful treatment of typhoid fever with conventional antibiotics. Antimicrobial resistance (AMR) in Salmonella is acquired either by mutations in the genomic DNA or by acquiring extrachromosomal DNA via horizontal gene transfer. In addition, Salmonella can form a subpopulation of antibiotic persistent (AP) cells that can survive at high concentrations of antibiotics. These have reduced the effectiveness of the first and second lines of antibiotics used to treat Salmonella infection. The recurrent and chronic carriage of S. Typhi in human hosts further complicates the treatment process, as a remarkable shift in the immune response from pro-inflammatory Th1 to anti-inflammatory Th2 is observed. Recent studies have also highlighted the overlap between AP, persistent infection (PI) and AMR. These incidents have revealed several areas of research. In this review, we have put forward a timeline for the evolution of antibiotic resistance in Salmonella and discussed the different mechanisms of the same availed by the pathogen at the genotypic and phenotypic levels. Further, we have presented a detailed discussion on Salmonella antibiotic persistence (AP), PI, the host and bacterial virulence factors that can influence PI, and how both AP and PI can lead to AMR.
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Affiliation(s)
- Atish Roy Chowdhury
- Department of Microbiology and Cell Biology, Division of Biological Sciences, Indian Institute of Science, Bangalore, India
| | - Debapriya Mukherjee
- Department of Microbiology and Cell Biology, Division of Biological Sciences, Indian Institute of Science, Bangalore, India
| | - Ritika Chatterjee
- Department of Microbiology and Cell Biology, Division of Biological Sciences, Indian Institute of Science, Bangalore, India
| | - Dipshikha Chakravortty
- Department of Microbiology and Cell Biology, Division of Biological Sciences, Indian Institute of Science, Bangalore, India
- School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, India
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3
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Piña-Iturbe A, Hoppe-Elsholz G, Suazo ID, Kalergis AM, Bueno SM. Subinhibitory antibiotic concentrations promote the excision of a genomic island carried by the globally spread carbapenem-resistant Klebsiella pneumoniae sequence type 258. Microb Genom 2023; 9:001138. [PMID: 38079200 PMCID: PMC10763509 DOI: 10.1099/mgen.0.001138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 11/07/2023] [Indexed: 12/18/2023] Open
Abstract
The ICEKp258.2 genomic island (GI) has been proposed as an important factor for the emergence and success of the globally spread carbapenem-resistant Klebsiella pneumoniae sequence type (ST) 258. However, a characterization of this horizontally acquired element is lacking. Using bioinformatic and experimental approaches, we found that ICEKp258.2 is not confined to ST258 and ST512, but also carried by ST3795 strains and emergent invasive multidrug-resistant pathogens from ST1519. We also identified several ICEKp258.2-like GIs spread among different K. pneumoniae STs, other Klebsiella species and even other pathogen genera, uncovering horizontal gene transfer events between different STs and bacterial genera. Also, the comparative and phylogenetic analyses of the ICEKp258.2-like GIs revealed that the most closely related ICEKp258.2-like GIs were harboured by ST11 strains. Importantly, we found that subinhibitory concentrations of antibiotics used in treating K. pneumoniae infections can induce the excision of this GI and modulate its gene expression. Our findings provide the basis for the study of ICEKp258.2 and its role in the success of K. pneumoniae ST258. They also highlight the potential role of antibiotics in the spread of ICEKp258.2-like GIs among bacterial pathogens.
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Affiliation(s)
- Alejandro Piña-Iturbe
- Millennium Institute on Immunology and Immunotherapy, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
- Present address: Escuela de Medicina Veterinaria, Facultad de Agronomía y Sistemas Naturales, Facultad de Ciencias Biológicas y Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 7820436, Chile
| | - Guillermo Hoppe-Elsholz
- Millennium Institute on Immunology and Immunotherapy, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Isidora D. Suazo
- Millennium Institute on Immunology and Immunotherapy, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Alexis M. Kalergis
- Millennium Institute on Immunology and Immunotherapy, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
- Departamento de Endocrinología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330023, Chile
| | - Susan M. Bueno
- Millennium Institute on Immunology and Immunotherapy, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
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Mikkelsen K, Bowring JZ, Ng YK, Svanberg Frisinger F, Maglegaard JK, Li Q, Sieber RN, Petersen A, Andersen PS, Rostøl JT, Høyland-Kroghsbo NM, Ingmer H. An Endogenous Staphylococcus aureus CRISPR-Cas System Limits Phage Proliferation and Is Efficiently Excised from the Genome as Part of the SCC mec Cassette. Microbiol Spectr 2023; 11:e0127723. [PMID: 37404143 PMCID: PMC10434264 DOI: 10.1128/spectrum.01277-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 06/11/2023] [Indexed: 07/06/2023] Open
Abstract
CRISPR-Cas is an adaptive immune system that allows bacteria to inactivate mobile genetic elements. Approximately 50% of bacteria harbor CRISPR-Cas; however, in the human pathogen Staphylococcus aureus, CRISPR-Cas loci are less common and often studied in heterologous systems. We analyzed the prevalence of CRISPR-Cas in genomes of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated in Denmark. Only 2.9% of the strains carried CRISPR-Cas systems, but for strains of sequence type ST630, over half were positive. All CRISPR-Cas loci were type III-A and located within the staphylococcal cassette chromosome mec (SCCmec) type V(5C2&5), conferring β-lactam resistance. Curiously, only 23 different CRISPR spacers were identified in 69 CRISPR-Cas positive strains, and almost identical SCCmec cassettes, CRISPR arrays, and cas genes are present in staphylococcal species other than S. aureus, suggesting that these were transferred horizontally. For the ST630 strain 110900, we demonstrate that the SCCmec cassette containing CRISPR-Cas is excised from the chromosome at high frequency. However, the cassette was not transferable under the conditions investigated. One of the CRISPR spacers targets a late gene in the lytic bacteriophage phiIPLA-RODI, and we show that the system protects against phage infection by reducing phage burst size. However, CRISPR-Cas can be overloaded or circumvented by CRISPR escape mutants. Our results imply that the endogenous type III-A CRISPR-Cas system in S. aureus is active against targeted phages, albeit with low efficacy. This suggests that native S. aureus CRISPR-Cas offers only partial immunity and in nature may work in tandem with other defense systems. IMPORTANCE CRISPR-Cas is an adaptive immune system protecting bacteria and archaea against mobile genetic elements such as phages. In strains of Staphylococcus aureus, CRISPR-Cas is rare, but when present, it is located within the SCCmec element, which encodes resistance to methicillin and other β-lactam antibiotics. We show that the element is excisable, suggesting that the CRISPR-Cas locus is transferable. In support of this, we found almost identical CRISPR-Cas-carrying SCCmec elements in different species of non-S. aureus staphylococci, indicating that the system is mobile but only rarely acquires new spacers in S. aureus. Additionally, we show that in its endogenous form, the S. aureus CRISPR-Cas is active but inefficient against lytic phages that can overload the system or form escape mutants. Thus, we propose that CRISPR-Cas in S. aureus offers only partial immunity in native systems and so may work with other defense systems to prevent phage-mediated killing.
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Affiliation(s)
- Kasper Mikkelsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Janine Zara Bowring
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Yong Kai Ng
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | | | | | - Qiuchun Li
- Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
| | - Raphael N. Sieber
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Andreas Petersen
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Paal Skytt Andersen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Jakob T. Rostøl
- Centre for Bacterial Resistance Biology, Imperial College London, London, United Kingdom
| | - Nina Molin Høyland-Kroghsbo
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Hanne Ingmer
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
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Xiao J, Huang J, Xue X, Wang C, Sun Y, Zheng L, Zhao X, Wang X, Zhao X, Xue H. Novel cassette chromosome recombinases CcrA8B9 catalyse the excision and integration of the staphylococcal cassette chromosome mec element. J Antimicrob Chemother 2023; 78:440-444. [PMID: 36480296 DOI: 10.1093/jac/dkac410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Accepted: 11/15/2022] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVES A defining feature of MRSA is the SCCmec element. The excision and integration of SCCmec elements are catalysed by Ccr recombinases. Currently, seven ccrA, eight ccrB and two ccrC allotypes have been described. However, there have been no recent reports of a novel Ccr recombinase and thus this area should be explored. METHODS According to the proposed criteria of the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements (IWG-SCC) committee, novel ccr genes were explored by searching the genome of our laboratory staphylococcal strains, which were isolated from bovine mastitis in Northwest China. The biological activity of the novel Ccr recombinases to excise and integrate SCCmec elements was determined. The distribution of the novel ccr genes in staphylococci was conducted by querying the NCBI nr/nt database. RESULTS We report a set of novel Ccr recombinases CcrA8B9, which share nucleotide identities of 46.6%-50.2% and 47.4%-52.8% with the ccrA and ccrB alleles, respectively. We used PCR to show that CcrA8B9 can excise and integrate the SCCmec element. Furthermore, using NCBI BLAST we showed that the ccrA8B9 genes exist in other staphylococcal strains. Unlike the common ccr genes, ccrA8B9 is located outside the SCCmec/SCC element. CONCLUSIONS The novel Ccr recombinases CcrA8B9 can help excise and integrate SCCmec/SCC from the genome and provide a new way to facilitate the transmission of SCCmec/SCC elements among staphylococci.
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Affiliation(s)
- Jinhe Xiao
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Jianguo Huang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Xuemei Xue
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Chen Wang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Yanting Sun
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Liangjun Zheng
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Xu Zhao
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Xiaokun Wang
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Xin Zhao
- Department of Animal Science, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Huping Xue
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
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6
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Wagner TM, Howden BP, Sundsfjord A, Hegstad K. Transiently silent acquired antimicrobial resistance: an emerging challenge in susceptibility testing. J Antimicrob Chemother 2023; 78:586-598. [PMID: 36719135 PMCID: PMC9978586 DOI: 10.1093/jac/dkad024] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Acquisition and expression of antimicrobial resistance (AMR) mechanisms in bacteria are often associated with a fitness cost. Thus, evolutionary adaptation and fitness cost compensation may support the advance of subpopulations with a silent resistance phenotype when the antibiotic selection pressure is absent. However, reports are emerging on the transient nature of silent acquired AMR, describing genetic alterations that can change the expression of these determinants to a clinically relevant level of resistance, and the association with breakthrough infections causing treatment failures. This phenomenon of transiently silent acquired AMR (tsaAMR) is likely to increase, considering the overall expansion of acquired AMR in bacterial pathogens. Moreover, the augmented use of genotypic methods in combination with conventional phenotypic antimicrobial susceptibility testing (AST) will increasingly enable the detection of genotype and phenotype discrepancy. This review defines tsaAMR as acquired antimicrobial resistance genes with a corresponding phenotype within the wild-type distribution or below the clinical breakpoint for susceptibility for which genetic alterations can mediate expression to a clinically relevant level of resistance. References to in vivo resistance development and therapeutic failures caused by selected resistant subpopulations of tsaAMR in Gram-positive and Gram-negative pathogens are given. We also describe the underlying molecular mechanisms, including alterations in the expression, reading frame or copy number of AMR determinants, and discuss the clinical relevance concerning challenges for conventional AST.
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Affiliation(s)
- Theresa Maria Wagner
- Research Group for Host-Microbe Interactions, Department of Medical Biology, Faculty of Health Sciences, UiT the Arctic University of Norway, Tromsø, Norway
| | - Benjamin Peter Howden
- Microbiological Diagnostic Unit Public Health Laboratory, The Department of Microbiology and Immunology, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
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Huber C, Wolf SA, Ziebuhr W, Holmes MA, Assmann J, Lübke-Becker A, Thürmer A, Semmler T, Brombach J, Bethe A, Bischoff M, Wieler LH, Epping L, Walther B. How to survive pig farming: Mechanism of SCC mec element deletion and metabolic stress adaptation in livestock-associated MRSA. Front Microbiol 2022; 13:969961. [PMID: 36504815 PMCID: PMC9728531 DOI: 10.3389/fmicb.2022.969961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 10/04/2022] [Indexed: 11/24/2022] Open
Abstract
Previous research on methicillin susceptible Staphylococcus aureus (MSSA) belonging to livestock-associated (LA-) sequence type (ST) 398, isolated from pigs and their local surroundings, indicated that differences between these MSSA and their methicillin resistant predecessors (MRSA) are often limited to the absence of the staphylococcal cassette chromosome mec (SCCmec) and few single nucleotide polymorphisms. So far, our understanding on how LA-MRSA endure the environmental conditions associated with pig-farming as well as the putative impact of this particular environment on the mobilisation of SCCmec elements is limited. Thus, we performed in-depth genomic and transcriptomic analyses using the LA-MRSA ST398 strain IMT38951 and its methicillin susceptible descendant. We identified a mosaic-structured SCCmec region including a putative replicative SCCmecVc which is absent from the MSSA chromosome through homologous recombination. Based on our data, such events occur between short repetitive sequences identified within and adjacent to two distinct alleles of the large cassette recombinase genes C (ccrC). We further evaluated the global transcriptomic response of MRSA ST398 to particular pig-farm associated conditions, i.e., contact with host proteins (porcine serum) and a high ammonia concentration. Differential expression of global regulators involved in stress response control were identified, i.e., ammonia-induced alternative sigma factor B-depending activation of genes for the alkaline shock protein 23, the heat shock response and the accessory gene regulator (agr)-controlled transcription of virulence factors. Exposure to serum transiently induced the transcription of distinct virulence factor encoding genes. Transcription of genes reported for mediating the loss of methicillin resistance, especially ccrC, was not significantly different compared to the unchallenged controls. We concluded that, from an evolutionary perspective, bacteria may save energy by incidentally dismissing a fully replicative SCCmec element in contrast to the induction of ccr genes on a population scale. Since the genomic SCCmec integration site is a hot-spot of recombination, occasional losses of elements of 16 kb size may restore capacities for the uptake of foreign genetic material. Subsequent spread of resistance, on the other hand, might depend on the autonomous replication machinery of the deleted SCCmec elements that probably enhance chances for reintegration of SCCmec into susceptible genomes by mere multiplication.
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Affiliation(s)
- Charlotte Huber
- Advanced Light and Electron Microscopy (ZBS4), Robert Koch Institute, Berlin, Germany
| | - Silver A. Wolf
- Genome Sequencing and Genomic Epidemiology (MF2), Robert Koch Institute, Berlin, Germany
| | - Wilma Ziebuhr
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Mark A. Holmes
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Julia Assmann
- Advanced Light and Electron Microscopy (ZBS4), Robert Koch Institute, Berlin, Germany
| | - Antina Lübke-Becker
- Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
| | - Andrea Thürmer
- Genome Sequencing and Genomic Epidemiology (MF2), Robert Koch Institute, Berlin, Germany
| | - Torsten Semmler
- Genome Sequencing and Genomic Epidemiology (MF2), Robert Koch Institute, Berlin, Germany
| | - Julian Brombach
- Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
| | - Astrid Bethe
- Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
| | - Markus Bischoff
- Institute of Medical Microbiology and Hygiene, Saarland University, Homburg, Germany
| | - Lothar H. Wieler
- Methodology and Research Infrastructure, Robert Koch Institute, Berlin, Germany
| | - Lennard Epping
- Genome Sequencing and Genomic Epidemiology (MF2), Robert Koch Institute, Berlin, Germany
| | - Birgit Walther
- Advanced Light and Electron Microscopy (ZBS4), Robert Koch Institute, Berlin, Germany,*Correspondence: Birgit Walther,
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8
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Lima-Noronha MA, Fonseca DLH, Oliveira RS, Freitas RR, Park JH, Galhardo RS. Sending out an SOS - the bacterial DNA damage response. Genet Mol Biol 2022; 45:e20220107. [PMID: 36288458 PMCID: PMC9578287 DOI: 10.1590/1678-4685-gmb-2022-0107] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 07/15/2022] [Indexed: 11/04/2022] Open
Abstract
The term “SOS response” was first coined by Radman in 1974, in an intellectual effort to put together the data suggestive of a concerted gene expression program in cells undergoing DNA damage. A large amount of information about this cellular response has been collected over the following decades. In this review, we will focus on a few of the relevant aspects about the SOS response: its mechanism of control and the stressors which activate it, the diversity of regulated genes in different species, its role in mutagenesis and evolution including the development of antimicrobial resistance, and its relationship with mobile genetic elements.
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Affiliation(s)
- Marco A. Lima-Noronha
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
| | - Douglas L. H. Fonseca
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
| | - Renatta S. Oliveira
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
| | - Rúbia R. Freitas
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
| | - Jung H. Park
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
| | - Rodrigo S. Galhardo
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
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9
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Eisenreich W, Rudel T, Heesemann J, Goebel W. Link Between Antibiotic Persistence and Antibiotic Resistance in Bacterial Pathogens. Front Cell Infect Microbiol 2022; 12:900848. [PMID: 35928205 PMCID: PMC9343593 DOI: 10.3389/fcimb.2022.900848] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 06/21/2022] [Indexed: 12/15/2022] Open
Abstract
Both, antibiotic persistence and antibiotic resistance characterize phenotypes of survival in which a bacterial cell becomes insensitive to one (or even) more antibiotic(s). However, the molecular basis for these two antibiotic-tolerant phenotypes is fundamentally different. Whereas antibiotic resistance is genetically determined and hence represents a rather stable phenotype, antibiotic persistence marks a transient physiological state triggered by various stress-inducing conditions that switches back to the original antibiotic sensitive state once the environmental situation improves. The molecular basics of antibiotic resistance are in principle well understood. This is not the case for antibiotic persistence. Under all culture conditions, there is a stochastically formed, subpopulation of persister cells in bacterial populations, the size of which depends on the culture conditions. The proportion of persisters in a bacterial population increases under different stress conditions, including treatment with bactericidal antibiotics (BCAs). Various models have been proposed to explain the formation of persistence in bacteria. We recently hypothesized that all physiological culture conditions leading to persistence converge in the inability of the bacteria to re-initiate a new round of DNA replication caused by an insufficient level of the initiator complex ATP-DnaA and hence by the lack of formation of a functional orisome. Here, we extend this hypothesis by proposing that in this persistence state the bacteria become more susceptible to mutation-based antibiotic resistance provided they are equipped with error-prone DNA repair functions. This is - in our opinion - in particular the case when such bacterial populations are exposed to BCAs.
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Affiliation(s)
- Wolfgang Eisenreich
- Bavarian NMR Center – Structural Membrane Biochemistry, Department of Chemistry, Technische Universität München, Garching, Germany
- *Correspondence: Wolfgang Eisenreich,
| | - Thomas Rudel
- Chair of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Jürgen Heesemann
- Max von Pettenkofer-Institute, Ludwig Maximilian University of Munich, München, Germany
| | - Werner Goebel
- Max von Pettenkofer-Institute, Ludwig Maximilian University of Munich, München, Germany
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10
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Dimitriu T. Evolution of horizontal transmission in antimicrobial resistance plasmids. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35849537 DOI: 10.1099/mic.0.001214] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Mobile genetic elements (MGEs) are one of the main vectors for the spread of antimicrobial resistance (AMR) across bacteria, due to their ability to move horizontally between bacterial lineages. Horizontal transmission of AMR can increase AMR prevalence at multiple scales, from increasing the prevalence of infections by resistant bacteria to pathogen epidemics and worldwide spread of AMR across species. Among MGEs, conjugative plasmids are the main contributors to the spread of AMR. This review discusses the selective pressures acting on MGEs and their hosts to promote or limit the horizontal transmission of MGEs, the mechanisms by which transmission rates can evolve, and their implications for limiting the spread of AMR, with a focus on AMR plasmids.
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11
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Hailemariam M, Alemayehu T, Tadesse B, Nigussie N, Agegnehu A, Habtemariam T, Ali M, Mitiku E, Azerefegne E. Major bacterial isolate and antibiotic resistance from routine clinical samples in Southern Ethiopia. Sci Rep 2021; 11:19710. [PMID: 34611232 PMCID: PMC8492677 DOI: 10.1038/s41598-021-99272-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 08/13/2021] [Indexed: 02/08/2023] Open
Abstract
Currently, antibiotic-resistant bacterial infections are a challenge for the health care system. Although physicians demand timely drug resistance data to guide empirical treatment, local data is rather scarce. Hence, this study performed a retrospective analysis of microbiological findings at the Hawassa public hospital. Secondary data were retrieved to assess the prevalence and level of drug resistance for the most common bacterial isolates from clinical samples processed at Hawassa University Comprehensive Specialized Hospital. Out of 1085 clinical samples processed in the microbiology laboratory, the prevalence of bacterial infection was 32.6%. Bacterial bloodstream infection was higher in children than in adults (OR, 4; 95% CI 1.8-14.6; p = 0.005). E. coli and K. pneumoniae were the commonest bacterial isolate both in children (36.8%, 26.3%) and in adults (33.3%, 26.7%) from the urine sample while, the leading bacteria identified from the CSF sample was P. aeruginosa, 37% in children and 43% in adult. In this study, all identified bacterial isolates were multi-drug resistant (MDR) ranging from 50 to 91%. The highest proportion of MDR was S. aureus 91.1 followed by K. pneumoniae 87.6%. Since the nationwide investigation of bacterial isolate, and drug resistance is rare in Ethiopia, a report from such type of local surveillance is highly useful to guide empirical therapy by providing awareness on the level resistance of isolates.
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Affiliation(s)
- Mengistu Hailemariam
- grid.192268.60000 0000 8953 2273School of Medical Laboratory Science, Hawassa University College of Medicine and Health Sciences, P.O. Box 1560, Hawassa, Ethiopia
| | - Tsegaye Alemayehu
- grid.192268.60000 0000 8953 2273School of Medical Laboratory Science, Hawassa University College of Medicine and Health Sciences, P.O. Box 1560, Hawassa, Ethiopia
| | - Bereket Tadesse
- grid.192268.60000 0000 8953 2273Hawassa University Comprehensive and Specialized Hospital, Hawassa, Ethiopia
| | - Netsanete Nigussie
- grid.192268.60000 0000 8953 2273Hawassa University Comprehensive and Specialized Hospital, Hawassa, Ethiopia
| | - Asnakech Agegnehu
- grid.192268.60000 0000 8953 2273Hawassa University Comprehensive and Specialized Hospital, Hawassa, Ethiopia
| | - Techilo Habtemariam
- grid.192268.60000 0000 8953 2273Hawassa University Comprehensive and Specialized Hospital, Hawassa, Ethiopia
| | - Mulubrhan Ali
- grid.192268.60000 0000 8953 2273School of Medical Laboratory Science, Hawassa University College of Medicine and Health Sciences, P.O. Box 1560, Hawassa, Ethiopia
| | - Enkosilassie Mitiku
- grid.192268.60000 0000 8953 2273Hawassa University Comprehensive and Specialized Hospital, Hawassa, Ethiopia
| | - Elshaday Azerefegne
- grid.192268.60000 0000 8953 2273Hawassa University Comprehensive and Specialized Hospital, Hawassa, Ethiopia
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12
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Liu P, Hao Z, Liu M, Niu M, Sun P, Yan S, Zhao L, Zhao X. Genetic mutations in adaptive evolution of growth-independent vancomycin-tolerant Staphylococcus aureus. J Antimicrob Chemother 2021; 76:2765-2773. [PMID: 34302174 DOI: 10.1093/jac/dkab260] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 06/29/2021] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Antibiotic tolerance allows bacteria to overcome antibiotic treatment transiently and potentially accelerates the emergence of resistance. However, our understanding of antibiotic tolerance at the genetic level during adaptive evolution of Staphylococcus aureus remains incomplete. We sought to identify the mutated genes and verify the role of these genes in the formation of vancomycin tolerance in S. aureus. METHODS Vancomycin-susceptible S. aureus strain Newman was used to induce vancomycin-tolerant isolates in vitro by cyclic exposure under a high concentration of vancomycin (20× MIC). WGS and Sanger sequencing were performed to identify the genetic mutations. The function of mutated genes in vancomycin-tolerant isolates were verified by gene complementation. Other phenotypes of vancomycin-tolerant isolates were also determined, including mutation frequency, autolysis, lysostaphin susceptibility, cell wall thickness and cross-tolerance. RESULTS A series of vancomycin-tolerant S. aureus (VTSA) strains were isolated and 18 mutated genes were identified by WGS. Among these genes, pbp4, htrA, stp1, pth and NWMN_1068 were confirmed to play roles in VTSA formation. Mutation of mutL promoted the emergence of VTSA. All VTSA showed no changes in growth phenotype. Instead, they exhibited reduced autolysis, decreased lysostaphin susceptibility and thickened cell walls. In addition, all VTSA strains were cross-tolerant to antibiotics targeting cell wall synthesis but not to quinolones and lipopeptides. CONCLUSIONS Our results demonstrate that genetic mutations are responsible for emergence of phenotypic tolerance and formation of vancomycin tolerance may lie in cell wall changes in S. aureus.
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Affiliation(s)
- Pilong Liu
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China.,Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Zehua Hao
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Miaomiao Liu
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Mingze Niu
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Peng Sun
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Shunhua Yan
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Lixiu Zhao
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Xin Zhao
- Department of Animal Science, McGill University, Ste. Anne de Bellevue, Quebec, Canada
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13
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Sridhar S, Forrest S, Pickard D, Cormie C, Lees EA, Thomson NR, Dougan G, Baker S. Inhibitory Concentrations of Ciprofloxacin Induce an Adaptive Response Promoting the Intracellular Survival of Salmonella enterica Serovar Typhimurium. mBio 2021; 12:e0109321. [PMID: 34154399 PMCID: PMC8262899 DOI: 10.1128/mbio.01093-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 05/19/2021] [Indexed: 12/02/2022] Open
Abstract
Antimicrobial resistance (AMR) is a pressing global health crisis, which has been fueled by the sustained use of certain classes of antimicrobials, including fluoroquinolones. While the genetic mutations responsible for decreased fluoroquinolone (ciprofloxacin) susceptibility are known, the implications of ciprofloxacin exposure on bacterial growth, survival, and interactions with host cells are not well described. Aiming to understand the influence of inhibitory concentrations of ciprofloxacin in vitro, we subjected three clinical isolates of Salmonella enterica serovar Typhimurium to differing concentrations of ciprofloxacin, dependent on their MICs, and assessed the impact on bacterial growth, morphology, and transcription. We further investigated the differential morphology and transcription that occurred following ciprofloxacin exposure and measured the ability of ciprofloxacin-treated bacteria to invade and replicate in host cells. We found that ciprofloxacin-exposed S. Typhimurium is able to recover from inhibitory concentrations of ciprofloxacin and that the drug induces specific morphological and transcriptional signatures associated with the bacterial SOS response, DNA repair, and intracellular survival. In addition, ciprofloxacin-treated S. Typhimurium has increased capacity for intracellular replication in comparison to that of untreated organisms. These data suggest that S. Typhimurium undergoes an adaptive response under ciprofloxacin perturbation that promotes cellular survival, a consequence that may justify more measured use of ciprofloxacin for Salmonella infections. The combination of multiple experimental approaches provides new insights into the collateral effects that ciprofloxacin and other antimicrobials have on invasive bacterial pathogens. IMPORTANCE Antimicrobial resistance is a critical concern in global health. In particular, there is rising resistance to fluoroquinolones, such as ciprofloxacin, a first-line antimicrobial for many Gram-negative pathogens. We investigated the adaptive response of clinical isolates of Salmonella enterica serovar Typhimurium to ciprofloxacin, finding that the bacteria adapt in short timespans to high concentrations of ciprofloxacin in a way that promotes intracellular survival during early infection. Importantly, by studying three clinically relevant isolates, we were able to show that individual isolates respond differently to ciprofloxacin and that for each isolate, there was a heterogeneous response under ciprofloxacin treatment. The heterogeneity that arises from ciprofloxacin exposure may drive survival and proliferation of Salmonella during treatment and lead to drug resistance.
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Affiliation(s)
- Sushmita Sridhar
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
- Wellcome Sanger Institute, Hinxton, United Kingdom
| | - Sally Forrest
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
| | - Derek Pickard
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
| | - Claire Cormie
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
| | - Emily A. Lees
- Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | - Nicholas R. Thomson
- Wellcome Sanger Institute, Hinxton, United Kingdom
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Gordon Dougan
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
| | - Stephen Baker
- Department of Medicine, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
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14
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Chen L, Huang J, Huang X, He Y, Sun J, Dai X, Wang X, Shafiq M, Wang L. Horizontal Transfer of Different erm(B)-Carrying Mobile Elements Among Streptococcus suis Strains With Different Serotypes. Front Microbiol 2021; 12:628740. [PMID: 33841355 PMCID: PMC8032901 DOI: 10.3389/fmicb.2021.628740] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 02/03/2021] [Indexed: 11/24/2022] Open
Abstract
Macrolide-resistant Streptococcus suis is highly prevalent worldwide. The acquisition of the erm(B) gene mediated by mobile genetic elements (MGEs) in particular integrative and conjugative elements (ICEs) is recognized as the main reason for the rapid spread of macrolide-resistant streptococcal strains. However, knowledge about different erm(B)-carrying elements responsible for the widespread of macrolide resistance and their transferability in S. suis remains poorly understood. In the present study, two erm(B)- and tet(O)-harboring putative ICEs, designated as ICESsuYSB17_rplL and ICESsuYSJ15_rplL, and a novel erm(B)- and aadE-spw-like-carrying genomic island (GI), named GISsuJHJ17_rpsI, were identified to be excised from the chromosome and transferred among S. suis strains with different serotypes. ICESsuYSB17_rplL and ICESsuYSJ15_rplL were integrated downstream the rplL gene, a conserve locus of the ICESa2603 family. GISsuJHJ17_rpsI, with no genes belonging to the conjugation module, was integrated into the site of rpsI. All transconjugants did not exhibit obvious fitness cost by growth curve and competition assays when compared with the recipient. The results demonstrate that different erm(B)-carrying elements were presented and highlight the role of these elements in the dissemination of macrolide resistance in S. suis.
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Affiliation(s)
- Li Chen
- Ministry of Education (MOE) Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Jinhu Huang
- Ministry of Education (MOE) Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Xinxin Huang
- Technical Center for Animal, Plant and Food Inspection and Quarantine of Shanghai Customs, Shanghai, China
| | - Yuping He
- Technical Center for Animal, Plant and Food Inspection and Quarantine of Shanghai Customs, Shanghai, China
| | - Junjie Sun
- Ministry of Education (MOE) Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Xingyang Dai
- Ministry of Education (MOE) Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Xiaoming Wang
- Ministry of Education (MOE) Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Muhammad Shafiq
- Ministry of Education (MOE) Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Liping Wang
- Ministry of Education (MOE) Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
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15
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Song Z, Zuo L, Li C, Tian Y, Wang H. Copper Ions Facilitate the Conjugative Transfer of SXT/R391 Integrative and Conjugative Element Across Bacterial Genera. Front Microbiol 2021; 11:616792. [PMID: 33603719 PMCID: PMC7884315 DOI: 10.3389/fmicb.2020.616792] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 12/22/2020] [Indexed: 12/16/2022] Open
Abstract
Copper can persist stably in the environment for prolonged periods. Except for inducing antibiotic resistance in bacteria, copper ions (Cu2+) can facilitate the horizontal transfer of plasmid DNA. However, whether and how Cu2+ can accelerate the conjugative transfer of SXT/R391 integrative and conjugative element (ICE) is still largely unknown. In this study, Proteus mirabilis ChSC1905, harboring an SXT/R391 ICE that carried 21 antibiotic resistance genes (ARGs), was used as a donor, and Escherichia coli EC600 was used as a recipient. Cu2+, at subinhibitory and environmentally relevant concentrations (1–10 μmol/L), significantly accelerated the conjugative transfer of SXT/R391 ICE across bacterial genera (from P. mirabilis to E. coli) (p < 0.05). The combined analyses of phenotypic tests and genome-wide sequencing indicated that reactive oxygen species (ROS) production and cell membrane permeability were critical in the enhanced conjugative transfer of SXT/R391 ICE. Furthermore, the expression of genes related to cell adhesion and ATP synthesis was also significantly upregulated on exposure to Cu2+ at a concentration of 5 μmol/L. This study clarified the potential mechanisms of Cu2+ to promote the conjugative transfer of SXT/R391 ICE, revealing the potential risk imposed by Cu2+ on the horizontal transfer of SXT/R391 ICE-mediated ARGs.
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Affiliation(s)
- Zhou Song
- Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Lei Zuo
- Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Cui Li
- Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Yiming Tian
- Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Hongning Wang
- Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
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16
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Memar MY, Yekani M, Celenza G, Poortahmasebi V, Naghili B, Bellio P, Baghi HB. The central role of the SOS DNA repair system in antibiotics resistance: A new target for a new infectious treatment strategy. Life Sci 2020; 262:118562. [PMID: 33038378 DOI: 10.1016/j.lfs.2020.118562] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/15/2020] [Accepted: 10/01/2020] [Indexed: 01/19/2023]
Abstract
Bacteria have a considerable ability and potential to acquire resistance against antimicrobial agents by acting diverse mechanisms such as target modification or overexpression, multidrug transporter systems, and acquisition of drug hydrolyzing enzymes. Studying the mechanisms of bacterial cell physiology is mandatory for the development of novel strategies to control the antimicrobial resistance phenomenon, as well as for the control of infections in clinics. The SOS response is a cellular DNA repair mechanism that has an essential role in the bacterial biologic process involved in resistance to antibiotics. The activation of the SOS network increases the resistance and tolerance of bacteria to stress and, as a consequence, to antimicrobial agents. Therefore, SOS can be an applicable target for the discovery of new antimicrobial drugs. In the present review, we focus on the central role of SOS response in bacterial resistance mechanisms and its potential as a new target for control of resistant pathogens.
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Affiliation(s)
- Mohammad Yousef Memar
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Students' Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mina Yekani
- Department of Microbiology, Faculty of Medicine, Kashan University of Medical Sciences, Kashan, Iran; Student Research Committee, Kashan University of Medical Sciences, Kashan, Iran
| | - Giuseppe Celenza
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy.
| | - Vahdat Poortahmasebi
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; Research Center for Clinical Virology, Tehran University of Medical Sciences, Tehran, Iran
| | - Behrooz Naghili
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Pierangelo Bellio
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy
| | - Hossein Bannazadeh Baghi
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
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17
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Li H, Wei Z, Wang C, Chen W, He Y, Zhang C. Gender Differences in Gastric Cancer Survival: 99,922 Cases Based on the SEER Database. J Gastrointest Surg 2020; 24:1747-1757. [PMID: 31346960 DOI: 10.1007/s11605-019-04304-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 06/10/2019] [Indexed: 01/31/2023]
Abstract
OBJECTIVES To evaluate gender differences in initial presentation, pathology and outcomes with GC (GC). METHODS The 1973-2013 Surveillance Epidemiology and End Results (SEER) 17-registry database was analysed for renal tumours from 1973 to 2013 coded as primary site "stomach". After various exclusions, a final study group of 99,922 cases with complete data was obtained. Demographic variables analysed included age, sex, marital status and race. Tumour variables included size, stage at diagnosis, grade, primary site, treatment and histology. Primary outcome variables included overall survival (OS) and cancer-specific survival (CSS). RESULTS Overall, 96,501 gastric cancer patients were identified. Of those, 34,862 (36.2%) were women. For woman, log-rank test showed that OS and CSS were significantly longer in man (p < 0.0001). In Cox regression analysis, woman was associated with a significantly improved OS [(HR of death in 1973 to 2003 = 0.87, 95% CI = 0.85-0.89, P < 0.001) (HR of death in 2004 to 2013 = 0.94, 95% CI = 0.91-0.97, P < 0.001)] and cancer-specific survival [(HR of death in 1973 to 2003 = 0.90, 95% CI = 0.87-0.92, P < 0.001) (HR of death in 2004 to 2013 = 0.90, 95% CI = 0.87-0.93, P < 0.001)]. When performing a Kaplan-Meier curve analysis after propensity score matching, gender persisted to be a significant survival of woman for OS and CSS. CONCLUSIONS Men present with larger, higher stage, higher grade GC than women. OS and CSS are better in women, which is significantly different.
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Affiliation(s)
- Huafu Li
- Dermatovenerology Digestive Medicine Center, The Seventh Affiliated Hospital of Sun Yat-Sen University, No. 628, Zhenyuan Rd, Guangming (New) Dist., Shenzhen, China.,Department of Gastrointestinopancreatic Surgery, The First Affiliated Hospital of Sun Yat-Sen University, 58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China
| | - Zhewei Wei
- Department of Gastrointestinopancreatic Surgery, The First Affiliated Hospital of Sun Yat-Sen University, 58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China
| | - Chunming Wang
- Dermatovenerology Digestive Medicine Center, The Seventh Affiliated Hospital of Sun Yat-Sen University, No. 628, Zhenyuan Rd, Guangming (New) Dist., Shenzhen, China.,Department of Gastrointestinopancreatic Surgery, The First Affiliated Hospital of Sun Yat-Sen University, 58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China
| | - Wei Chen
- Department of Gastrointestinopancreatic Surgery, The First Affiliated Hospital of Sun Yat-Sen University, 58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China
| | - Yulong He
- Dermatovenerology Digestive Medicine Center, The Seventh Affiliated Hospital of Sun Yat-Sen University, No. 628, Zhenyuan Rd, Guangming (New) Dist., Shenzhen, China. .,Department of Gastrointestinopancreatic Surgery, The First Affiliated Hospital of Sun Yat-Sen University, 58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China.
| | - Changhua Zhang
- Dermatovenerology Digestive Medicine Center, The Seventh Affiliated Hospital of Sun Yat-Sen University, No. 628, Zhenyuan Rd, Guangming (New) Dist., Shenzhen, China. .,Department of Gastrointestinopancreatic Surgery, The First Affiliated Hospital of Sun Yat-Sen University, 58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China.
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18
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Jiang Y, Liu Y, Zhang J. Antibiotic contaminants reduced the treatment efficiency of UV-C on Microcystis aeruginosa through hormesis. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 261:114193. [PMID: 32088440 DOI: 10.1016/j.envpol.2020.114193] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 02/12/2020] [Accepted: 02/13/2020] [Indexed: 06/10/2023]
Abstract
Antibiotic contaminants exert stimulatory hormetic effects in cyanobacteria at low (ng L-1) concentrations, which may interfere with the control of cyanobacterial bloom in aquatic environments exhibiting combined pollution. This study investigated the influence of a mixture of four popular antibiotics (sulfamethoxazole, amoxicillin, ciprofloxacin, and tetracycline) during the application of UV-C irradiation for controlling the bloom of Microcystis aeruginosa. In the absence of antibiotics, 100-500 mJ cm-2 UV-C irradiation reduced cell density, growth rate, chlorophyll a content, Fv/Fm value and microcystin concentration in M. aeruginosa in a dose-dependent manner through the downregulation of proteins related to cell division, chlorophyll synthesis, photosynthesis and microcystin synthesis. UV-C irradiation stimulated microcystin release through the upregulation of the microcystin release regulatory protein (mcyH). The presence of 40 ng L-1 antibiotic mixture during UV-C treatment significantly reduced (p < 0.05) the treatment efficiency of 100-300 mJ cm-2 UV-C on microcystin concentration, while 80 and 160 ng L-1 antibiotic mixture significantly reduced (p < 0.05) the treatment efficiency of 100-500 mJ cm-2 UV-C on cell density and microcystin concentration. The antibiotic mixture alleviated the toxicity of UV-C on M. aeruginosa through a significant stimulation of photosynthetic activity (p < 0.05) and the upregulation of proteins involved in photosynthesis, biosynthesis, protein expression, and DNA repair. Microcystin release in UV-C-treated cyanobacterial cells was further stimulated by the antibiotic mixture through the upregulation of mcyH and four ATP-binding cassette transport proteins. The interference effects of antibiotic contaminants should be fully considered when UV-C is applied to control cyanobacterial bloom in antibiotic-polluted environments. In order to eliminate the interference effects of antibiotics, the concentration of each target antibiotic is suggested to be controlled below 5 ng L-1 before the application of UV-C irradiation.
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Affiliation(s)
- Yunhan Jiang
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, People's Republic of China
| | - Ying Liu
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, People's Republic of China.
| | - Jian Zhang
- School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, People's Republic of China
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19
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Almebairik N, Zamudio R, Ironside C, Joshi C, Ralph JD, Roberts AP, Gould IM, Morrissey JA, Hijazi K, Oggioni MR. Genomic Stability of Composite SCC mec ACME and COMER-Like Genetic Elements in Staphylococcus epidermidis Correlates With Rate of Excision. Front Microbiol 2020; 11:166. [PMID: 32117176 PMCID: PMC7029739 DOI: 10.3389/fmicb.2020.00166] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 01/23/2020] [Indexed: 01/08/2023] Open
Abstract
The epidemiological success of methicillin-resistant Staphylococcus aureus USA300 has been associated with the presence of two mobile elements, the arginine catabolic mobile element (ACME) and the copper and mercury resistance (COMER) element. These two mobile elements are associated with resistance to copper, which has been related to host fitness and survival within macrophages. Several studies found that ACME is more prevalent, and exhibits greater diversity, in Staphylococcus epidermidis while COMER has not been identified in S. epidermidis or any other staphylococcal species. We aimed in this study to evaluate the presence and diversity of ACME and COMER-like elements in our S. epidermidis clinical isolates. The genomes of 58 S. epidermidis clinical isolates, collected between 2009 and 2018 in a Scottish hospital, were sequenced. A core-genome phylogenetic tree and genome based MLST typing showed that more than half of the isolates belong to the clinically predominant sequence type2 (ST2) and these isolates have been found to split into two lineages within the phylogenetic tree. Analysis showed the presence of SCCmec in the majority of isolates. Comparative analysis identified a cluster of ACME-positive isolates with most of them belonging to ST48. ACME showed high variation even between isolates of the same ACME type and ST. COMER-like elements have been identified in one of the two major hospital adapted drug resistant ST2 lineages; and showed high stability. This difference in stability at the genomic level correlates well with the up to one hundred times higher excision frequency found for the SCCmec elements in ACME-containing isolates compared to COMER-like element containing isolates. ACME/COMER-like element positive isolates did not show a significant phenotype of decreased copper susceptibility, while resistance to mercury was over-represented in COMER-like element positive isolates. To the best of our knowledge, this is the first molecular characterization of COMER-like elements in S. epidermidis isolates. The presence of the COMER-like elements is the most prominent accessory genome feature of these successful lineages suggesting that this chromosomal island contributes to the success and wide clinical distribution of ST2 S. epidermidis.
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Affiliation(s)
- Nada Almebairik
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Roxana Zamudio
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Corinne Ironside
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, United Kingdom
| | - Chaitanya Joshi
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, United Kingdom
| | - Joseph D Ralph
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Adam P Roberts
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Ian M Gould
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, United Kingdom
| | - Julie A Morrissey
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Karolin Hijazi
- School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, United Kingdom
| | - Marco R Oggioni
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
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20
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Rossi CC, Pereira MF, Giambiagi-deMarval M. Underrated Staphylococcus species and their role in antimicrobial resistance spreading. Genet Mol Biol 2020; 43:e20190065. [PMID: 32052827 PMCID: PMC7198029 DOI: 10.1590/1678-4685-gmb-2019-0065] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 05/06/2019] [Indexed: 01/06/2023] Open
Abstract
The increasing threat of antimicrobial resistance has shed light on the interconnection between humans, animals, the environment, and their roles in the exchange and spreading of resistance genes. In this review, we present evidences that show that Staphylococcus species, usually referred to as harmless or opportunistic pathogens, represent a threat to human and animal health for acting as reservoirs of antimicrobial resistance genes. The capacity of genetic exchange between isolates of different sources and species of the Staphylococcus genus is discussed with emphasis on mobile genetic elements, the contribution of biofilm formation, and evidences obtained either experimentally or through genome analyses. We also discuss the involvement of CRISPR-Cas systems in the limitation of horizontal gene transfer and its suitability as a molecular clock to describe the history of genetic exchange between staphylococci.
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Affiliation(s)
- Ciro César Rossi
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Laboratório de Microbiologia Molecular, Rio de Janeiro, RJ, Brazil
| | | | - Marcia Giambiagi-deMarval
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Laboratório de Microbiologia Molecular, Rio de Janeiro, RJ, Brazil
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21
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Blázquez J, Rodríguez-Beltrán J, Matic I. Antibiotic-Induced Genetic Variation: How It Arises and How It Can Be Prevented. Annu Rev Microbiol 2019; 72:209-230. [PMID: 30200850 DOI: 10.1146/annurev-micro-090817-062139] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
By targeting essential cellular processes, antibiotics provoke metabolic perturbations and induce stress responses and genetic variation in bacteria. Here we review current knowledge of the mechanisms by which these molecules generate genetic instability. They include production of reactive oxygen species, as well as induction of the stress response regulons, which lead to enhancement of mutation and recombination rates and modulation of horizontal gene transfer. All these phenomena influence the evolution and spread of antibiotic resistance. The use of strategies to stop or decrease the generation of resistant variants is also discussed.
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Affiliation(s)
- Jesús Blázquez
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CNB-CSIC), 28049 Madrid, Spain; .,Unidad de Enfermedades Infecciosas, Microbiologia y Medicina Preventiva, Hospital Universitario Virgen del Rocio, 41013 Seville, Spain.,Red Española de Investigacion en Patologia Infecciosa, Instituto de Salud Carlos III, 28029 Madrid, Spain
| | | | - Ivan Matic
- Faculté de Médecine Paris Descartes, INSERM 1001, CNRS, Université Paris-Descartes-Sorbonne Paris Cité, 75014 Paris, France;
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22
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Structural Insights into Bacteriophage GIL01 gp7 Inhibition of Host LexA Repressor. Structure 2019; 27:1094-1102.e4. [PMID: 31056420 DOI: 10.1016/j.str.2019.03.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 03/04/2019] [Accepted: 03/25/2019] [Indexed: 11/20/2022]
Abstract
Bacteria identify and respond to DNA damage using the SOS response. LexA, a central repressor in the response, has been implicated in the regulation of lysogeny in various temperate bacteriophages. During infection of Bacillus thuringiensis with GIL01 bacteriophage, LexA represses the SOS response and the phage lytic cycle by binding DNA, an interaction further stabilized upon binding of a viral protein, gp7. Here we report the crystallographic structure of phage-borne gp7 at 1.7-Å resolution, and characterize the 4:2 stoichiometry and potential interaction with LexA using surface plasmon resonance, static light scattering, and small-angle X-ray scattering. These data suggest that gp7 stabilizes LexA binding to operator DNA via coordination of the N- and C-terminal domains of LexA. Furthermore, we have found that gp7 can interact with LexA from Staphylococcus aureus, a significant human pathogen. Our results provide structural evidence as to how phage factors can directly associate with LexA to modulate the SOS response.
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23
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Becker K, van Alen S, Idelevich EA, Schleimer N, Seggewiß J, Mellmann A, Kaspar U, Peters G. Plasmid-Encoded Transferable mecB-Mediated Methicillin Resistance in Staphylococcus aureus. Emerg Infect Dis 2019; 24:242-248. [PMID: 29350135 PMCID: PMC5782906 DOI: 10.3201/eid2402.171074] [Citation(s) in RCA: 132] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
During cefoxitin-based nasal screening, phenotypically categorized methicillin-resistant Staphylococcus aureus (MRSA) was isolated and tested negative for the presence of the mecA and mecC genes as well as for the SCCmec-orfX junction region. The isolate was found to carry a mecB gene previously described for Macrococcus caseolyticus but not for staphylococcal species. The gene is flanked by β-lactam regulatory genes similar to mecR, mecI, and blaZ and is part of an 84.6-kb multidrug-resistance plasmid that harbors genes encoding additional resistances to aminoglycosides (aacA-aphD, aphA, and aadK) as well as macrolides (ermB) and tetracyclines (tetS). This further plasmidborne β-lactam resistance mechanism harbors the putative risk of acceleration or reacceleration of MRSA spread, resulting in broad ineffectiveness of β-lactams as a main therapeutic application against staphylococcal infections.
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24
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Yin D, Sun D, Han Z, Ni D, Norris A, Jiang CZ. PhERF2, an ethylene-responsive element binding factor, plays an essential role in waterlogging tolerance of petunia. HORTICULTURE RESEARCH 2019; 6:83. [PMID: 31645944 PMCID: PMC6804856 DOI: 10.1038/s41438-019-0165-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Revised: 05/01/2019] [Accepted: 05/09/2019] [Indexed: 05/22/2023]
Abstract
Ethylene-responsive element binding factors (ERFs) are involved in regulation of various stress responses in plants, but their biological functions in waterlogging stress are largely unclear. In this study, we identified a petunia (Petunia × hybrida) ERF gene, PhERF2, that was significantly induced by waterlogging in wild-type (WT). To study the regulatory role of PhERF2 in waterlogging responses, transgenic petunia plants with RNAi silencing and overexpression of PhERF2 were generated. Compared with WT plants, PhERF2 silencing compromised the tolerance of petunia seedlings to waterlogging, shown as 96% mortality after 4 days waterlogging and 14 days recovery, while overexpression of PhERF2 improved the survival of seedlings subjected to waterlogging. PhERF2-RNAi lines exhibited earlier and more severe leaf chlorosis and necrosis than WT, whereas plants overexpressing PhERF2 showed promoted growth vigor under waterlogging. Chlorophyll content was dramatically lower in PhERF2-silenced plants than WT or overexpression plants. Typical characteristics of programmed cell death (PCD), DNA condensation, and moon-shaped nuclei were only observed in PhERF2-overexpressing lines but not in PhERF2-RNAi or control lines. Furthermore, transcript abundances of the alcoholic fermentation-related genes ADH1-1, ADH1-2, ADH1-3, PDC1, and PDC2 were reduced in PhERF2-silenced plants, but increased in PhERF2-overexpressing plants following exposure to 12-h waterlogging. In contrast, expression of the lactate fermentation-related gene LDH was up-regulated in PhERF2-silenced plants, but down-regulated in its overexpressing plants. Moreover, PhERF2 was observed to directly bind to the ADH1-2 promoter bearing ATCTA motifs. Our results demonstrate that PhERF2 contributes to petunia waterlogging tolerance through modulation of PCD and alcoholic fermentation system.
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Affiliation(s)
- Dongmei Yin
- College of Ecology, Shanghai Institute of Technology, Shanghai, 201418 China
| | - Daoyang Sun
- College of Landscape Architecture and Arts, Northwest A&F University, Yangling, Shaanxi 712100 China
| | - Zhuqing Han
- College of Ecology, Shanghai Institute of Technology, Shanghai, 201418 China
| | - Dian Ni
- College of Ecology, Shanghai Institute of Technology, Shanghai, 201418 China
| | - Ayla Norris
- Crops Pathology & Genetic Research Unit, United States Department of Agriculture, Agricultural Research Service, Davis, CA 95616 USA
| | - Cai-Zhong Jiang
- Crops Pathology & Genetic Research Unit, United States Department of Agriculture, Agricultural Research Service, Davis, CA 95616 USA
- Department of Plant Sciences, University of California Davis, Davis, CA 95616 USA
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25
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Wu Z, Zhang L, Qiao D, Xue H, Zhao X. Functional Analyses of Cassette Chromosome Recombinase C2 (CcrC2) and Its Use in Eliminating Methicillin Resistance by Combining CRISPR-Cas9. ACS Synth Biol 2018; 7:2590-2599. [PMID: 30278126 DOI: 10.1021/acssynbio.8b00261] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Worldwide occurrence of methicillin-resistant Staphylococcus aureus (MRSA) poses enormous challenges for both communities and health care settings. Cassette chromosome recombinases (Ccr) specifically perform excision and acquisition of a staphylococcal cassette chromosome mec (SCC mec) in staphylococci and are responsible for the spread of methicillin resistance. This study explored the roles of CcrC2, a recently discovered Ccr, in the horizontal transfer of SCC mec and developed a potential means to control the spread of methicillin resistance. Knockout of CcrC2 completely aborted the excision of SCC mec, while overexpression of CcrC2 partially removed the SCC mec from the genome and transformed methicillin-resistant Staphylococcus aureus (MRSA) into methicillin-susceptible Staphylococcus aureus (MSSA). Moreover, two nucleotide residues (G5C6) in the direct repeat sequence within an att site were found to be critical for excision and acquisition efficiencies. To block the horizontal transfer of methicillin resistance, a SCC mec killer system was developed by combining the CcrC2-mediated SCC mec excision and the mecA-targeting CRISPR-Cas9 machinery. The SCC mec killer transformed MRSA to MSSA and disrupted the mecA-carrying SCC mec intermediate, thereby eliminating methicillin resistance determinant mecA gene inside a MRSA cell and blocking the horizontal transfer of SCC mec. The SCC mec killer was versatile for efficiently removing multiple types of SCC mec elements. It is envisioned that this approach could offer a new means to control the spread of methicillin resistance.
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Affiliation(s)
- Zhaowei Wu
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100 Shaanxi, People’s Republic of China
| | - Limin Zhang
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100 Shaanxi, People’s Republic of China
| | - Dandan Qiao
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100 Shaanxi, People’s Republic of China
| | - Huping Xue
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100 Shaanxi, People’s Republic of China
| | - Xin Zhao
- College of Animal Science and Technology, Northwest A&F University, Yangling, 712100 Shaanxi, People’s Republic of China
- Department of Animal Science, McGill University, Ste. Anne de Bellevue, Quebec H9X 3V9, Canada
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26
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Abstract
Staphylococcus aureus is a serious human pathogen with remarkable adaptive powers. Antibiotic-resistant clones rapidly emerge mainly by acquisition of antibiotic-resistance genes from other S. aureus strains or even from other genera. Transfer is mediated by a diverse complement of mobile genetic elements and occurs primarily by conjugation or bacteriophage transduction, with the latter traditionally being perceived as the primary route. Recent work on conjugation and transduction suggests that transfer by these mechanisms may be more extensive than previously thought, in terms of the range of plasmids that can be transferred by conjugation and the efficiency with which transduction occurs. Here, we review the main routes of antibiotic resistance gene transfer in S. aureus in the context of its biology as a human commensal and a life-threatening pathogen.
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Affiliation(s)
- Jakob Haaber
- Department of Veterinary and Animal Sciences, Faculty of Health & Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - José R Penadés
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Hanne Ingmer
- Department of Veterinary and Animal Sciences, Faculty of Health & Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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