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Furmanek-Blaszk B, Sektas M, Rybak B. High Prevalence of Plasmid-Mediated Quinolone Resistance among ESBL/AmpC-Producing Enterobacterales from Free-Living Birds in Poland. Int J Mol Sci 2023; 24:12804. [PMID: 37628984 PMCID: PMC10454011 DOI: 10.3390/ijms241612804] [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: 07/25/2023] [Revised: 08/08/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
In this study, we investigated the occurrence of plasmid-mediated quinolone resistance (PMQR) in extended-spectrum β-lactamase- (ESBL) and/or AmpC-type β-lactamase-producing Enterobacterales isolates from free-living birds in Poland. The prevalence of the qnrB19 gene was 63%, and the distribution of isolates in terms of bacterial species was as follows: 67% (22/33) corresponded to Escherichia coli, 83% (5/6) to Rahnella aquatilis, 44% (4/9) to Enterobacter cloacae and 33% (1/3) to Klebsiella pneumoniae. The qnrB19 gene was also found in a single isolate of Citrobacter freundii. The molecular characteristics of qnrB19-positive isolates pointed to extended-spectrum beta lactamase CTX-M as the most prevalent one (89%) followed by TEM (47%), AmpC (37%) and SHV (16%). This study demonstrates the widespread occurrence of PMQR-positive and ESBL/AmpC-producing Enterobacterales isolates in fecal samples from wild birds. In this work, plasmid pAM1 isolated from Escherichia coli strain SN25556 was completely sequenced. This plasmid is 3191 nucleotides long and carries the qnrB19 gene, which mediates decreased susceptibility to quinolones. It shares extensive homology with other previously described small qnrB19-harboring plasmids. The nucleotide sequence of pAM1 showed a variable region flanked by an oriT locus and a Xer recombination site. The presence of a putative recombination site was detected, suggesting that interplasmid recombination events might have played a role in the development of pAM1. Our results highlight the broad geographical spread of ColE-type Qnr resistance plasmids in clinical and environmental isolates of Enterobacterales. As expected from the results of phenotypic susceptibility testing, no resistance genes other than qnrB19 were identified.
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Affiliation(s)
- Beata Furmanek-Blaszk
- Department of Microbiology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland;
| | - Marian Sektas
- Department of Microbiology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland;
| | - Bartosz Rybak
- Department of Environmental Toxicology, Faculty of Health Sciences with Institute of Maritime and Tropical Medicine, Medical University of Gdansk, Debowa Str. 23A, 80-204 Gdansk, Poland;
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Chen CY, Nguyen LHT, Strobaugh TP. Sequence analysis and plasmid mobilization of a 6.6-kb kanamycin resistance plasmid, pSNC3-Kan, from a Salmonella enterica serotype Newport isolate. PLoS One 2022; 17:e0268502. [PMID: 35834529 PMCID: PMC9282650 DOI: 10.1371/journal.pone.0268502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 05/03/2022] [Indexed: 11/19/2022] Open
Abstract
Research on the transfer of antibiotic resistance plasmids has been mainly focused on the large multi-drug resistance conjugative plasmids, while the transmission of small mobilizable plasmids remains under-investigated. A series of diverse ColE-like kanamycin resistance plasmids (“KanR plasmids”) from Salmonella enterica were characterized previously. In this study, the 6.6-kb pSNC3-Kan from a Salmonella enterica serotype Newport isolate was investigated. It possessed highly conserved RNA I/II and Tn602 (IS903-aph-IS903) regions to two other KanR plasmids pSe-Kan and pSBardo-Kan, but carried a mobC-mobA/BD operon. The mobilization proteins encoded by the mob operon of pSNC3-Kan showed high sequence identity (~95%) to those of an E. coli plasmid pEC34B, except that MobE was not present; and were much less conserved to those of another KanR plasmid pSN11/00Kan (43% - 86% identity). Four structurally different KanR plasmids were investigated for their ability to be mobilized by the conjugal transfer (tra) genes from F and IncP plasmids. Transfer genes derived from IncP plasmids can efficiently mobilize KanR plasmids possessing the mob operons (mobC-mobA/BD), such as pSNC3-Kan and pSN11/00Kan, in bi-parental mating experiments. On the other hand, F tra genes were able to mobilize pU302S, pSNC3-Kan and pSe-Kan, but not pSN11/00Kan. A plasmid-borne mob operon was not required for mobilization of the oriT(F)-bearing pSe-Kan by the F tra genes. This study underscores the complexity of plasmid interaction and the importance of how small mobilizable plasmids may contribute to the spread of antibiotic resistance genes.
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Affiliation(s)
- Chin-Yi Chen
- Molecular Characterization of Foodborne Pathogens Research Unit, Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Wyndmoor, Pennsylvania, United States of America
- * E-mail:
| | - Ly-Huong T. Nguyen
- Molecular Characterization of Foodborne Pathogens Research Unit, Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Wyndmoor, Pennsylvania, United States of America
| | - Terence P. Strobaugh
- Molecular Characterization of Foodborne Pathogens Research Unit, Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Wyndmoor, Pennsylvania, United States of America
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3
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Xie M, Yang X, Xu Q, Ye L, Chen K, Zheng Z, Dong N, Sun Q, Shu L, Gu D, Chan EWC, Zhang R, Chen S. Clinical evolution of ST11 carbapenem resistant and hypervirulent Klebsiella pneumoniae. Commun Biol 2021; 4:650. [PMID: 34075192 PMCID: PMC8169677 DOI: 10.1038/s42003-021-02148-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 04/23/2021] [Indexed: 11/18/2022] Open
Abstract
Carbapenem-resistant and hypervirulent K. pneumoniae (CR-HvKP) strains that have emerged recently have caused infections of extremely high mortality in various countries. In this study, we discovered a conjugative plasmid that encodes carbapenem resistance and hypervirulence in a clinical ST86 K2 CR-HvKP, namely 17ZR-91. The conjugative plasmid (p17ZR-91-Vir-KPC) was formed by fusion of a non-conjugative pLVPK-like plasmid and a conjugative blaKPC-2-bearing plasmid and is present dynamically with two other non-fusion plasmids. Conjugation of p17ZR-91-Vir-KPC to other K. pneumoniae enabled them to rapidly express the carbapenem resistance and hypervirulence phenotypes. More importantly, genome analysis provided direct evidence that p17ZR-91-Vir-KPC could be directly transmitted from K2 CR-HvKP strain, 17ZR-91, to ST11 clinical K. pneumoniae strains to convert them into ST11 CR-HvKP strains, which explains the evolutionary mechanisms of recently emerged ST11 CR-HvKP strains. Carbapenem-resistant and hypervirulent Klebsiella pneumoniae strains are emerging. Here Xie et al. show that these phenotypes are carried on a plasmid formed from the fusion of a virulence plasmid with a conjugative plasmid.
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Affiliation(s)
- Miaomiao Xie
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong
| | - Xuemei Yang
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong
| | - Qi Xu
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong
| | - Lianwei Ye
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong
| | - Kaichao Chen
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong
| | - Zhiwei Zheng
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong
| | - Ning Dong
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong
| | - Qiaoling Sun
- Department of Clinical Laboratory, Second Affiliated Hospital of Zhejiang University, School of Medicine, Zhejiang, Hangzhou, China
| | - Lingbin Shu
- Department of Clinical Laboratory, Second Affiliated Hospital of Zhejiang University, School of Medicine, Zhejiang, Hangzhou, China
| | - Danxia Gu
- Department of Clinical Laboratory, Zhejiang Provincial People's Hospital, Hangzhou, China
| | - Edward Wai-Chi Chan
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong.,State Key Lab of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Rong Zhang
- Department of Clinical Laboratory, Second Affiliated Hospital of Zhejiang University, School of Medicine, Zhejiang, Hangzhou, China.
| | - Sheng Chen
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong.
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4
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Ramirez MS, Iriarte A, Reyes-Lamothe R, Sherratt DJ, Tolmasky ME. Small Klebsiella pneumoniae Plasmids: Neglected Contributors to Antibiotic Resistance. Front Microbiol 2019; 10:2182. [PMID: 31616398 PMCID: PMC6764390 DOI: 10.3389/fmicb.2019.02182] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 09/05/2019] [Indexed: 12/15/2022] Open
Abstract
Klebsiella pneumoniae is the causative agent of community- and, more commonly, hospital-acquired infections. Infections caused by this bacterium have recently become more dangerous due to the acquisition of multiresistance to antibiotics and the rise of hypervirulent variants. Plasmids usually carry genes coding for resistance to antibiotics or virulence factors, and the recent sequence of complete K. pneumoniae genomes showed that most strains harbor many of them. Unlike large plasmids, small, usually high copy number plasmids, did not attract much attention. However, these plasmids may include genes coding for specialized functions, such as antibiotic resistance, that can be expressed at high levels due to gene dosage effect. These genes may be part of mobile elements that not only facilitate their dissemination but also participate in plasmid evolution. Furthermore, high copy number plasmids may also play a role in evolution by allowing coexistence of mutated and non-mutated versions of a gene, which helps to circumvent the constraints imposed by trade-offs after certain genes mutate. Most K. pneumoniae plasmids 25-kb or smaller replicate by the ColE1-type mechanism and many of them are mobilizable. The transposon Tn1331 and derivatives were found in a high percentage of these plasmids. Another transposon that was found in representatives of this group is the bla KPC-containing Tn4401. Common resistance determinants found in these plasmids were aac(6')-Ib and genes coding for β-lactamases including carbapenemases.
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Affiliation(s)
- Maria S. Ramirez
- Center for Applied Biotechnology Studies, Department of Biological Sciences, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, CA, United States
| | - Andrés Iriarte
- Laboratorio de Biología Computacional, Departamento de Desarrollo Biotecnológico, Facultad de Medicina, Universidad de la República de Uruguay, Montevideo, Uruguay
| | | | - David J. Sherratt
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Marcelo E. Tolmasky
- Center for Applied Biotechnology Studies, Department of Biological Sciences, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, CA, United States
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
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Blackwell GA, Hall RM. Mobilisation of a small Acinetobacter plasmid carrying an oriT transfer origin by conjugative RepAci6 plasmids. Plasmid 2019; 103:36-44. [PMID: 30981890 DOI: 10.1016/j.plasmid.2019.04.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 04/09/2019] [Accepted: 04/09/2019] [Indexed: 11/18/2022]
Abstract
Most Acinetobacter plasmids are genus specific but their properties have not been investigated. Small plasmids with Rep_3 family replication initiation proteins and iterons are common in Acinetobacter baumannii and often carry antibiotic resistance genes and toxin-antitoxin systems. A RepAci1 plasmid, carrying the carbapenem resistance gene oxa23 in Tn2006 and a RepAci2 plasmid carrying the amikacin (kanamycin and neomycin) resistance gene aphA6 in TnaphA6 were identified. These two plasmids have related rep regions; the consensus 22 bp iteron repeats differ only at three positions and the RepA proteins are 84% identical. However, they were shown to be compatible, whereas the RepAci1 plasmid displaced another RepAci1 plasmid demonstrating that they were incompatible. Despite encoding no mobilisation proteins, the RepAci1 plasmid was transferred to a new host at low frequency when a conjugatively proficient RepAci6 plasmid was present, whereas the RepAci2 plasmid carrying mobA and mobC mobilisation genes was not. Comparison of the sequences of the mobilised and mobilising plasmids revealed a short region of high similarity that is upstream of the predicted mobilisation genes in the RepAci6 plasmid, and has an organisation similar to that of F-type oriT transfer origins. The segment carrying the oriT-like region is present in many RepAci1 plasmids, including ones carrying the cabarpenem resistance genes oxa24 or oxa58 in dif modules, and in some RepAci2 or other Rep_3 plasmids of further types, including one carrying the tet39 tetracycline resistance determinant. These plasmids are also likely to be mobilised, spreading resistance.
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Affiliation(s)
- Grace A Blackwell
- School of Life and Environmental Sciences, The University of Sydney, NSW 2006, Australia
| | - Ruth M Hall
- School of Life and Environmental Sciences, The University of Sydney, NSW 2006, Australia.
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6
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Marquez-Ortiz RA, Haggerty L, Olarte N, Duarte C, Garza-Ramos U, Silva-Sanchez J, Castro BE, Sim EM, Beltran M, Moncada MV, Valderrama A, Castellanos JE, Charles IG, Vanegas N, Escobar-Perez J, Petty NK. Genomic Epidemiology of NDM-1-Encoding Plasmids in Latin American Clinical Isolates Reveals Insights into the Evolution of Multidrug Resistance. Genome Biol Evol 2018; 9:1725-1741. [PMID: 28854628 PMCID: PMC5554438 DOI: 10.1093/gbe/evx115] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2017] [Indexed: 12/21/2022] Open
Abstract
Bacteria that produce the broad-spectrum Carbapenem antibiotic New Delhi Metallo-β-lactamase (NDM) place a burden on health care systems worldwide, due to the limited treatment options for infections caused by them and the rapid global spread of this antibiotic resistance mechanism. Although it is believed that the associated resistance gene blaNDM-1 originated in Acinetobacter spp., the role of Enterobacteriaceae in its dissemination remains unclear. In this study, we used whole genome sequencing to investigate the dissemination dynamics of blaNDM-1-positive plasmids in a set of 21 clinical NDM-1-positive isolates from Colombia and Mexico (Providencia rettgeri, Klebsiella pneumoniae, and Acinetobacter baumannii) as well as six representative NDM-1-positive Escherichia coli transconjugants. Additionally, the plasmids from three representative P. rettgeri isolates were sequenced by PacBio sequencing and finished. Our results demonstrate the presence of previously reported plasmids from K. pneumoniae and A. baumannii in different genetic backgrounds and geographically distant locations in Colombia. Three new previously unclassified plasmids were also identified in P. rettgeri from Colombia and Mexico, plus an interesting genetic link between NDM-1-positive P. rettgeri from distant geographic locations (Canada, Mexico, Colombia, and Israel) without any reported epidemiological links was discovered. Finally, we detected a relationship between plasmids present in P. rettgeri and plasmids from A. baumannii and K. pneumoniae. Overall, our findings suggest a Russian doll model for the dissemination of blaNDM-1 in Latin America, with P. rettgeri playing a central role in this process, and reveal new insights into the evolution and dissemination of plasmids carrying such antibiotic resistance genes.
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Affiliation(s)
- Ricaurte Alejandro Marquez-Ortiz
- Bacterial Molecular Genetics Laboratory, Universidad El Bosque, Bogotá, D.C., Colombia.,The ithree Institute, University of Technology Sydney, New South Wales, Australia
| | - Leanne Haggerty
- The ithree Institute, University of Technology Sydney, New South Wales, Australia
| | | | - Carolina Duarte
- Grupo de Microbiología, Instituto Nacional de Salud, Bogotá, Colombia
| | - Ulises Garza-Ramos
- Instituto Nacional de Salud Pública (INSP), CISEI, Cuernavaca, Morelos, México
| | - Jesus Silva-Sanchez
- Instituto Nacional de Salud Pública (INSP), CISEI, Cuernavaca, Morelos, México
| | - Betsy E Castro
- Bacterial Molecular Genetics Laboratory, Universidad El Bosque, Bogotá, D.C., Colombia
| | - Eby M Sim
- The ithree Institute, University of Technology Sydney, New South Wales, Australia
| | - Mauricio Beltran
- Grupo de Microbiología, Instituto Nacional de Salud, Bogotá, Colombia
| | - María V Moncada
- Bacterial Molecular Genetics Laboratory, Universidad El Bosque, Bogotá, D.C., Colombia
| | | | - Jaime E Castellanos
- Grupo de Patogénesis Infecciosa, Universidad Nacional de Colombia, Bogotá, D.C., Colombia
| | - Ian G Charles
- The ithree Institute, University of Technology Sydney, New South Wales, Australia
| | - Natasha Vanegas
- Bacterial Molecular Genetics Laboratory, Universidad El Bosque, Bogotá, D.C., Colombia.,The ithree Institute, University of Technology Sydney, New South Wales, Australia
| | - Javier Escobar-Perez
- Bacterial Molecular Genetics Laboratory, Universidad El Bosque, Bogotá, D.C., Colombia
| | - Nicola K Petty
- The ithree Institute, University of Technology Sydney, New South Wales, Australia
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Abstract
Microbes produce an extraordinary array of microbial defense systems. These include broad-spectrum classical antibiotics critical to human health concerns; metabolic by-products, such as the lactic acids produced by lactobacilli; lytic agents, such as lysozymes found in many foods; and numerous types of protein exotoxins and bacteriocins. The abundance and diversity of this biological arsenal are clear. Lactic acid production is a defining trait of lactic acid bacteria. Bacteriocins are found in almost every bacterial species examined to date, and within a species, tens or even hundreds of different kinds of bacteriocins are produced. Halobacteria universally produce their own version of bacteriocins, the halocins. Streptomycetes commonly produce broad-spectrum antibiotics. It is clear that microbes invest considerable energy in the production and elaboration of antimicrobial mechanisms. What is less clear is how such diversity arose and what roles these biological weapons play in microbial communities. One family of microbial defense systems, the bacteriocins, has served as a model for exploring evolutionary and ecological questions. In this review, current knowledge of how the extraordinary range of bacteriocin diversity arose and is maintained in one species of bacteria, Escherichia coli, is assessed and the role these toxins play in mediating microbial dynamics is discussed.
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O'Brien FG, Yui Eto K, Murphy RJT, Fairhurst HM, Coombs GW, Grubb WB, Ramsay JP. Origin-of-transfer sequences facilitate mobilisation of non-conjugative antimicrobial-resistance plasmids in Staphylococcus aureus. Nucleic Acids Res 2015; 43:7971-83. [PMID: 26243776 PMCID: PMC4652767 DOI: 10.1093/nar/gkv755] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 07/14/2015] [Indexed: 11/17/2022] Open
Abstract
Staphylococcus aureus is a common cause of hospital, community and livestock-associated infections and is increasingly resistant to multiple antimicrobials. A significant proportion of antimicrobial-resistance genes are plasmid-borne, but only a minority of S. aureus plasmids encode proteins required for conjugative transfer or Mob relaxase proteins required for mobilisation. The pWBG749 family of S. aureus conjugative plasmids can facilitate the horizontal transfer of diverse antimicrobial-resistance plasmids that lack Mob genes. Here we reveal that these mobilisable plasmids carry copies of the pWBG749 origin-of-transfer (oriT) sequence and that these oriT sequences facilitate mobilisation by pWBG749. Sequences resembling the pWBG749 oriT were identified on half of all sequenced S. aureus plasmids, including the most prevalent large antimicrobial-resistance/virulence-gene plasmids, pIB485, pMW2 and pUSA300HOUMR. oriT sequences formed five subfamilies with distinct inverted-repeat-2 (IR2) sequences. pWBG749-family plasmids encoding each IR2 were identified and pWBG749 mobilisation was found to be specific for plasmids carrying matching IR2 sequences. Specificity of mobilisation was conferred by a putative ribbon-helix-helix-protein gene smpO. Several plasmids carried 2–3 oriT variants and pWBG749-mediated recombination occurred between distinct oriT sites during mobilisation. These observations suggest this relaxase-in trans mechanism of mobilisation by pWBG749-family plasmids is a common mechanism of plasmid dissemination in S. aureus.
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Affiliation(s)
- Frances G O'Brien
- CHIRI Biosciences Precinct, School of Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley WA 6102, Australia Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research, School of Veterinary Sciences and Life Sciences, Murdoch University and School of Biomedical Sciences, Curtin University, Perth, Western Australia, Australia
| | - Karina Yui Eto
- CHIRI Biosciences Precinct, School of Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley WA 6102, Australia
| | - Riley J T Murphy
- CHIRI Biosciences Precinct, School of Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley WA 6102, Australia
| | - Heather M Fairhurst
- CHIRI Biosciences Precinct, School of Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley WA 6102, Australia
| | - Geoffrey W Coombs
- CHIRI Biosciences Precinct, School of Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley WA 6102, Australia Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research, School of Veterinary Sciences and Life Sciences, Murdoch University and School of Biomedical Sciences, Curtin University, Perth, Western Australia, Australia PathWest Laboratory Medicine, Fiona Stanley Hospital, Perth, Western Australia, Australia
| | - Warren B Grubb
- CHIRI Biosciences Precinct, School of Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley WA 6102, Australia Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research, School of Veterinary Sciences and Life Sciences, Murdoch University and School of Biomedical Sciences, Curtin University, Perth, Western Australia, Australia
| | - Joshua P Ramsay
- CHIRI Biosciences Precinct, School of Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley WA 6102, Australia Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research, School of Veterinary Sciences and Life Sciences, Murdoch University and School of Biomedical Sciences, Curtin University, Perth, Western Australia, Australia
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9
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Papagiannitsis CC, Dolejska M, Izdebski R, Dobiasova H, Studentova V, Esteves FJ, Derde LPG, Bonten MJM, Hrabák J, Gniadkowski M. Characterization of pKP-M1144, a Novel ColE1-Like Plasmid Encoding IMP-8, GES-5, and BEL-1 β-Lactamases, from a Klebsiella pneumoniae Sequence Type 252 Isolate. Antimicrob Agents Chemother 2015; 59:5065-8. [PMID: 26033721 PMCID: PMC4505226 DOI: 10.1128/aac.00937-15] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 05/29/2015] [Indexed: 11/20/2022] Open
Abstract
IMP-8 metallo-β-lactamase was identified in Klebsiella pneumoniae sequence type 252 (ST252), isolated in a Portuguese hospital in 2009. blaIMP-8 was the first gene cassette of a novel class 3 integron, In1144, also carrying the blaGES-5, blaBEL-1, and aacA4 cassettes. In1144 was located on a ColE1-like plasmid, pKP-M1144 (12,029 bp), with a replication region of limited nucleotide similarity to those of other RNA-priming plasmids, such as pJHCMW1. In1144 and pKP-M1144 represent an interesting case of evolution of resistance determinants in Gram-negative bacteria.
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Affiliation(s)
- Costas C Papagiannitsis
- Faculty of Medicine and University Hospital in Plzen, Charles University in Prague, Plzen, Czech Republic National Medicines Institute, Warsaw, Poland
| | - Monika Dolejska
- Department of Biology and Wildlife Diseases, Faculty of Veterinary Hygiene and Ecology, University of Veterinary and Pharmaceutical Sciences Brno, Brno, Czech Republic CEITEC VFU, University of Veterinary and Pharmaceutical Sciences Brno, Brno, Czech Republic
| | | | - Hana Dobiasova
- Department of Biology and Wildlife Diseases, Faculty of Veterinary Hygiene and Ecology, University of Veterinary and Pharmaceutical Sciences Brno, Brno, Czech Republic CEITEC VFU, University of Veterinary and Pharmaceutical Sciences Brno, Brno, Czech Republic
| | - Vendula Studentova
- Faculty of Medicine and University Hospital in Plzen, Charles University in Prague, Plzen, Czech Republic
| | | | | | | | - Jaroslav Hrabák
- Faculty of Medicine and University Hospital in Plzen, Charles University in Prague, Plzen, Czech Republic Biomedical Center, Faculty of Medicine in Plzen, Charles University in Prague, Plzen, Czech Republic
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10
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Plasmid-Mediated Antibiotic Resistance and Virulence in Gram-negatives: the Klebsiella pneumoniae Paradigm. Microbiol Spectr 2014; 2:1-15. [PMID: 25705573 DOI: 10.1128/microbiolspec.plas-0016-2013] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Plasmids harbor genes coding for specific functions including virulence factors and antibiotic resistance that permit bacteria to survive the hostile environment found in the host and resist treatment. Together with other genetic elements such as integrons and transposons, and using a variety of mechanisms, plasmids participate in the dissemination of these traits resulting in the virtual elimination of barriers among different kinds of bacteria. In this article we review the current information about physiology and role in virulence and antibiotic resistance of plasmids from the gram-negative opportunistic pathogen Klebsiella pneumoniae. This bacterium has acquired multidrug resistance and is the causative agent of serious communityand hospital-acquired infections. It is also included in the recently defined ESKAPE group of bacteria that cause most of US hospital infections.
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11
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A cointegrate-like plasmid that facilitates dissemination by conjugation of the extended-spectrum β-lactamase CTX-M-17. Antimicrob Agents Chemother 2013; 57:5191-2. [PMID: 23877684 DOI: 10.1128/aac.01365-13] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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12
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Ramirez MS, Nikolaidis N, Tolmasky ME. Rise and dissemination of aminoglycoside resistance: the aac(6')-Ib paradigm. Front Microbiol 2013; 4:121. [PMID: 23730301 PMCID: PMC3656343 DOI: 10.3389/fmicb.2013.00121] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 04/29/2013] [Indexed: 11/21/2022] Open
Abstract
Enzymatic modification is a prevalent mechanism by which bacteria defeat the action of antibiotics. Aminoglycosides are often inactivated by aminoglycoside modifying enzymes encoded by genes present in the chromosome, plasmids, and other genetic elements. The AAC(6′)-Ib (aminoglycoside 6′-N-acetyltransferase type Ib) is an enzyme of clinical importance found in a wide variety of gram-negative pathogens. The AAC(6′)-Ib enzyme is of interest not only because of his ubiquity but also because of other characteristics, it presents significant microheterogeneity at the N-termini and the aac(6′)-Ib gene is often present in integrons, transposons, plasmids, genomic islands, and other genetic structures. Excluding the highly heterogeneous N-termini, there are 45 non-identical AAC(6′)-Ib related entries in the NCBI database, 32 of which have identical name in spite of not having identical amino acid sequence. While some variants conserved similar properties, others show dramatic differences in specificity, including the case of AAC(6′)-Ib-cr that mediates acetylation of ciprofloxacin representing a rare case where a resistance enzyme acquires the ability to utilize an antibiotic of a different class as substrate. Efforts to utilize antisense technologies to turn off expression of the gene or to identify enzymatic inhibitors to induce phenotypic conversion to susceptibility are under way.
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Affiliation(s)
- María S Ramirez
- Department of Biological Science, Center for Applied Biotechnology Studies, College of Natural Sciences and Mathematics, California State University Fullerton Fullerton, CA, USA
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Differential distribution of plasmid-mediated quinolone resistance genes in clinical enterobacteria with unusual phenotypes of quinolone susceptibility from Argentina. Antimicrob Agents Chemother 2013; 57:2467-75. [PMID: 23478955 DOI: 10.1128/aac.01615-12] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We studied a collection of 105 clinical enterobacteria with unusual phenotypes of quinolone susceptibility to analyze the occurrence of plasmid-mediated quinolone resistance (PMQR) and oqx genes and their implications for quinolone susceptibility. The oqxA and oqxB genes were found in 31/34 (91%) Klebsiella pneumoniae and 1/3 Klebsiella oxytoca isolates. However, the oqxA- and oqxB-harboring isolates lacking other known quinolone resistance determinants showed wide ranges of susceptibility to nalidixic acid and ciprofloxacin. Sixty of the 105 isolates (57%) harbored at least one PMQR gene [qnrB19, qnrB10, qnrB2, qnrB1, qnrS1, or aac(6')-Ib-cr)], belong to 8 enterobacterial species, and were disseminated throughout the country, and most of them were categorized as susceptible by the current clinical quinolone susceptibility breakpoints. We developed a disk diffusion-based method to improve the phenotypic detection of aac(6')-Ib-cr. The most common PMQR genes in our collection [qnrB19, qnrB10, and aac(6')-Ib-cr] were differentially distributed among enterobacterial species, and two different epidemiological settings were evident. First, the species associated with community-acquired infections (Salmonella spp. and Escherichia coli) mainly harbored qnrB19 (a unique PMQR gene) located in small ColE1-type plasmids that might constitute its natural reservoirs. qnrB19 was not associated with an extended-spectrum β-lactamase phenotype. Second, the species associated with hospital-acquired infections (Enterobacter spp., Klebsiella spp., and Serratia marcescens) mainly harbored qnrB10 in ISCR1-containing class 1 integrons that may also have aac(6')-Ib-cr as a cassette within the variable region. These two PMQR genes were strongly associated with an extended-spectrum β-lactamase phenotype. Therefore, this differential distribution of PMQR genes is strongly influenced by their linkage or lack of linkage to integrons.
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Small plasmids harboring qnrB19: a model for plasmid evolution mediated by site-specific recombination at oriT and Xer sites. Antimicrob Agents Chemother 2012; 56:1821-7. [PMID: 22290975 DOI: 10.1128/aac.06036-11] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Plasmids pPAB19-1, pPAB19-2, pPAB19-3, and pPAB19-4, isolated from Salmonella and Escherichia coli clinical strains from hospitals in Argentina, were completely sequenced. These plasmids include the qnrB19 gene and are 2,699, 3,082, 2,989, and 2,702 nucleotides long, respectively, and they share extensive homology among themselves and with other previously described small qnrB19-harboring plasmids. The genetic environment of qnrB19 in all four plasmids is identical to that in these other plasmids and in transposons such as Tn2012, Tn5387, and Tn5387-like. Nucleotide sequence comparisons among these and previously described plasmids showed a variable region characterized by being flanked by an oriT locus and a Xer recombination site. We propose that this arrangement could play a role in the evolution of plasmids and present a model for DNA swapping between plasmid molecules mediated by site-specific recombination events at oriT and a Xer target site.
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Abstract
Aminoglycosides have been an essential component of the armamentarium in the treatment of life-threatening infections. Unfortunately, their efficacy has been reduced by the surge and dissemination of resistance. In some cases the levels of resistance reached the point that rendered them virtually useless. Among many known mechanisms of resistance to aminoglycosides, enzymatic modification is the most prevalent in the clinical setting. Aminoglycoside modifying enzymes catalyze the modification at different -OH or -NH₂ groups of the 2-deoxystreptamine nucleus or the sugar moieties and can be nucleotidyltransferases, phosphotransferases, or acetyltransferases. The number of aminoglycoside modifying enzymes identified to date as well as the genetic environments where the coding genes are located is impressive and there is virtually no bacteria that is unable to support enzymatic resistance to aminoglycosides. Aside from the development of new aminoglycosides refractory to as many as possible modifying enzymes there are currently two main strategies being pursued to overcome the action of aminoglycoside modifying enzymes. Their successful development would extend the useful life of existing antibiotics that have proven effective in the treatment of infections. These strategies consist of the development of inhibitors of the enzymatic action or of the expression of the modifying enzymes.
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Characterization of small ColE-like plasmids mediating widespread dissemination of the qnrB19 gene in commensal enterobacteria. Antimicrob Agents Chemother 2009; 54:678-82. [PMID: 20008783 DOI: 10.1128/aac.01160-09] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this work, we have characterized two small ColE-like plasmids (pECY6-7, 2.7 kb in size, and pECC14-9, of 3.0 kb), encoding the QnrB19 quinolone resistance determinant, that were carried by several clonally unrelated quinolone-resistant commensal Escherichia coli strains isolated from healthy children living in different urban areas of Peru and Bolivia. The two plasmids are closely related to each other and carry the qnrB19 gene as the sole resistance determinant, located in a conserved genetic context between the plasmid RNAII sequence (which controls plasmid replication) and the plasmid Xer site (involved in plasmid dimer resolution). ISEcp1-like or other putative insertion sequences are not present in the qnrB19-flanking regions or elsewhere on the plasmids. Since we previously observed a high prevalence (54%) of qnrB genes in the metagenomes of commensal enterobacteria from the same population of healthy children, the presence of pECY6-7- and pECC14-9-like plasmids in those qnrB-positive metagenomes was investigated by PCR mapping. Both plasmids were found to be highly prevalent (67% and 16%, respectively) in the qnrB-positive metagenomes, suggesting that dissemination of these small plasmids played a major role in the widespread dissemination of qnrB genes observed in commensal enterobacteria from healthy children living in those areas.
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Cascales E, Buchanan SK, Duché D, Kleanthous C, Lloubès R, Postle K, Riley M, Slatin S, Cavard D. Colicin biology. Microbiol Mol Biol Rev 2007; 71:158-229. [PMID: 17347522 PMCID: PMC1847374 DOI: 10.1128/mmbr.00036-06] [Citation(s) in RCA: 781] [Impact Index Per Article: 45.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Colicins are proteins produced by and toxic for some strains of Escherichia coli. They are produced by strains of E. coli carrying a colicinogenic plasmid that bears the genetic determinants for colicin synthesis, immunity, and release. Insights gained into each fundamental aspect of their biology are presented: their synthesis, which is under SOS regulation; their release into the extracellular medium, which involves the colicin lysis protein; and their uptake mechanisms and modes of action. Colicins are organized into three domains, each one involved in a different step of the process of killing sensitive bacteria. The structures of some colicins are known at the atomic level and are discussed. Colicins exert their lethal action by first binding to specific receptors, which are outer membrane proteins used for the entry of specific nutrients. They are then translocated through the outer membrane and transit through the periplasm by either the Tol or the TonB system. The components of each system are known, and their implication in the functioning of the system is described. Colicins then reach their lethal target and act either by forming a voltage-dependent channel into the inner membrane or by using their endonuclease activity on DNA, rRNA, or tRNA. The mechanisms of inhibition by specific and cognate immunity proteins are presented. Finally, the use of colicins as laboratory or biotechnological tools and their mode of evolution are discussed.
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Affiliation(s)
- Eric Cascales
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires,Institut de Biologie Structurale et Microbiologie, Centre National de la Recherche Scientifique, UPR 9027, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
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18
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Pasquali F, Kehrenberg C, Manfreda G, Schwarz S. Physical linkage of Tn3 and part of Tn1721 in a tetracycline and ampicillin resistance plasmid from Salmonella Typhimurium. J Antimicrob Chemother 2005; 55:562-5. [PMID: 15731203 DOI: 10.1093/jac/dkh553] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES The complete nucleotide sequence of the 12 656 bp plasmid pFPTB1 from Salmonella enterica subsp. enterica serovar Typhimurium, which mediates resistance to tetracyclines and ampicillin, was determined. The plasmid was analysed for potential reading frames and structural features indicative of transposons and transposon relics. METHODS Plasmid pFPTB1 was transformed into Escherichia coli JM109, overlapping restriction fragments were cloned into E. coli plasmid vectors and sequenced. In vitro susceptibility testing was carried out to confirm the resistance phenotype mediated by this plasmid. RESULTS Plasmid pFPTB1 contains a complete Tn3-like transposon of 4950 bp consisting of the left terminal repeat, Tn3-related tnpR and tnpA genes for transposition functions, a novel gene for ampicillin resistance bla(TEM-135), and the right terminal repeat. Immediately downstream, the terminal 5215 bp at the right end of a Tn1721-like transposon, including the right terminal repeat, a truncated transposase gene, as well as the genes tet(A) and tetR for tetracycline resistance, were detected. A 5 bp direct repeat, TAAAA, was seen immediately upstream of the Tn3 part and immediately downstream of the Tn1721 part. Plasmid pFPTB1 also carries a replication region similar to that of the Klebsiella pneumoniae plasmid pJHCMW1. CONCLUSION Plasmid pFPTB1 is one of the few completely sequenced plasmids from S. Typhimurium and harbours a novel transposon-like structure consisting of a Tn3-related part containing the bla(TEM-135) gene for ampicillin resistance and a Tn1721-related part containing the tetR-tet(A) genes for tetracycline resistance.
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Affiliation(s)
- Frédérique Pasquali
- Department of Food Science, Alma Mater Studiorum, University of Bologna, via San Giacomo 9, 40126 Bologna, Italy
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19
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Abstract
Microbes produce an extraordinary array of microbial defense systems. These include classical antibiotics, metabolic by-products, lytic agents, numerous types of protein exotoxins, and bacteriocins. The abundance and diversity of this potent arsenal of weapons are clear. Less clear are their evolutionary origins and the role they play in mediating microbial interactions. The goal of this review is to explore what we know about the evolution and ecology of the most abundant and diverse family of microbial defense systems: the bacteriocins. We summarize current knowledge of how such extraordinary protein diversity arose and is maintained in microbial populations and what role these toxins play in mediating microbial population-level and community-level dynamics. In the latter half of this review we focus on the potential role bacteriocins may play in addressing human health concerns and the current role they serve in food preservation.
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Affiliation(s)
- Margaret A Riley
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut 06511, USA.
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Sarno R, McGillivary G, Sherratt DJ, Actis LA, Tolmasky ME. Complete nucleotide sequence of Klebsiella pneumoniae multiresistance plasmid pJHCMW1. Antimicrob Agents Chemother 2002; 46:3422-7. [PMID: 12384346 PMCID: PMC128720 DOI: 10.1128/aac.46.11.3422-3427.2002] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The multiresistance plasmid pJHCMW1, harbored by a clinical Klebsiella pneumoniae strain isolated from a neonate with meningitis, was sequenced. A circular sequence of 11,354 bp was generated, of which 7,993 bp make up Tn1331, a transposon including the antibiotic resistance genes aac(6')-Ib, aadA1, bla(OXA-9), and bla(TEM-1). The gene aac(6')-Ib is included in a gene cassette, and both aadA1 and bla(OXA-9) are included in a single-gene cassette that may have arisen as a consequence of a recombination event involving two integrons. The pJHCMW1 plasmid replicates through a ColE1-like RNA-regulated mechanism, includes a functional oriT, and two loci with similarity to XerCD site-specific recombination target sites involved in plasmid stabilization by the resolution of multimers. One of these two loci, mwr, is active and has been the subject of previous studies, and the other, dxs, is not functional but binds the recombinase XerD with low affinity. Two additional open reading frames were identified, one with low similarity to two hypothetical membrane proteins from Mycobacterium tuberculosis and Mycobacterium leprae and the other with low similarity to psiB, a gene encoding a function that facilitates the establishment of the transferring plasmid in the recipient bacterial cell during the process of conjugation.
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Affiliation(s)
- Renee Sarno
- Department of Biological Science, Institute of Molecular Biology and Nutrition, College of Natural Science and Mathematics, California State University Fullerton, Fullerton, California 92834-6850, USA
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Abstract
The bacteriocin family is the most abundant and diverse group of bacterial defense systems. Bacteriocins range from the well-studied narrow spectrum, high molecular weight colicins produced by Escherichia coli and the short polypeptide lantibiotics of lactic acid bacteria to the relatively unknown halocins produced almost universally by the haolobacteria. The abundance and diversity of this potent arsenal of weapons is clear. Less clear is their evolutionary origins and the role they play in mediating microbial interactions. The goal of this review is to explore what we know about the evolution and ecology of the best-characterized family of bacteriocins, the colicins. We summarize current knowledge of how such extraordinary protein diversity arose and is maintained in microbial populations and what role these toxins play in mediating microbial population-level and community-level dynamics.
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Affiliation(s)
- Margaret A Riley
- Department of Ecology and Evolutionary Biology, 165 Prospect Street, Yale University, New Haven, CT 06511, USA.
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Cao V, Lambert T, Courvalin P. ColE1-like plasmid pIP843 of Klebsiella pneumoniae encoding extended-spectrum beta-lactamase CTX-M-17. Antimicrob Agents Chemother 2002; 46:1212-7. [PMID: 11959547 PMCID: PMC127148 DOI: 10.1128/aac.46.5.1212-1217.2002] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2001] [Revised: 10/28/2001] [Accepted: 01/28/2002] [Indexed: 11/20/2022] Open
Abstract
The resistance of Klebsiella pneumoniae BM4493, isolated in Ho Chi Minh City, Vietnam, to cefotaxime and aztreonam was due to production of a novel beta-lactamase, CTX-M-17. The bla(CTX-M-17) gene was borne by 7,086-bp plasmid pIP843, which was entirely sequenced and which was found to belong to the ColE1 family. The 876-bp bla(CTX-M-17) gene differed from bla(CTX-M-14) by 2 nucleotides, which led to the single amino acid substitution Glu289-->Lys. bla(CTX-M-17) was flanked upstream by an ISEcp1-like element and downstream by an insertion sequence (IS) IS903 variant designated IS903-C. The transcriptional start site of bla(CTX-M-17) was located 109 nucleotides upstream from the initiation codon in the ISEcp1-like element, which also provided the promoter sequences. Plasmid pIP843, which was non-self-transferable and nonmobilizable, contained five open reading frames transcribed in the same orientation. Regions homologous to sequences coding for putative RNA II and RNA I transcripts, a rom gene, which is involved in initiation of replication, and a cer-like gene, which is responsible for the stability of ColE1-like plasmids, were identified. Consensus sequences for putative replication (oriV) and transfer (oriT) origins were present. Results of primer extension experiments indicated that ISEcp1 provides the promoter for expression of bla(CTX-M-17) and may contribute to dissemination of this gene.
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Affiliation(s)
- Van Cao
- Unité des Agents Antibactériens, Institut Pasteur, 75724 Paris Cedex 15, France
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Pham H, Dery KJ, Sherratt DJ, Tolmasky ME. Osmoregulation of dimer resolution at the plasmid pJHCMW1 mwr locus by Escherichia coli XerCD recombination. J Bacteriol 2002; 184:1607-16. [PMID: 11872712 PMCID: PMC134880 DOI: 10.1128/jb.184.6.1607-1616.2002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Xer-mediated dimer resolution at the mwr site of plasmid pJHCMW1 is osmoregulated in Escherichia coli. Whereas under low-salt conditions, the site-specific recombination reaction is efficient, under high-salt conditions, it proceeds inefficiently. Regulation of dimer resolution is independent of H-NS and is mediated by changes in osmolarity rather than ionic effects. The low level of recombination at high salt concentrations can be overcome by high levels of PepA or by mutating the ARG box to a sequence closer to the E. coli ARG box consensus. The central region of the mwr core recombination site plays a role in regulation of site-specific recombination by the osmotic pressure of the medium.
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Affiliation(s)
- Huong Pham
- Division of Molecular Genetics, Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
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Riley MA, Pinou T, Wertz JE, Tan Y, Valletta CM. Molecular characterization of the klebicin B plasmid of Klebsiella pneumoniae. Plasmid 2001; 45:209-21. [PMID: 11407916 DOI: 10.1006/plas.2001.1519] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The nucleotide sequence of a bacteriocin-encoding plasmid isolated from Klebsiella pneumoniae (pKlebB-K17/80) has been determined. The encoded klebicin B protein is similar in sequence to the DNase pyocins and colicins, suggesting that klebicin B functions as a nonspecific endonuclease. The klebicin gene cluster, as well as the plasmid backbone, is a chimera, with regions similar to those of pore-former colicins, nuclease pyocins and colicins as well as noncolicinogenic plasmids. Similarities between pKlebB plasmid maintenance functions and those of the colicin E1 plasmid suggest that pKlebB is a member of the ColE1 plasmid replication family.
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Affiliation(s)
- M A Riley
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut 06520, USA
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25
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Tolmasky ME, Colloms S, Blakely G, Sherratt DJ. Stability by multimer resolution of pJHCMW1 is due to the Tn1331 resolvase and not to the Escherichia coli Xer system. MICROBIOLOGY (READING, ENGLAND) 2000; 146 ( Pt 3):581-589. [PMID: 10746761 DOI: 10.1099/00221287-146-3-581] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The plasmid pJHCMW1 encodes resistance to several aminoglycosides and beta-lactams and consists of a copy of the transposon Tn1331, a region including the replication functions, and a sequence with homology to ColE1 cer, designated mwr. In this work, the role of this cer-like site in ensuring the stable inheritance of pJHCMW1 by multimer resolution was studied. The Escherichia coli Xer site-specific recombination system acts at sites such as ColE1 cer to resolve plasmid multimers formed by homologous recombination, thereby maintaining plasmids in a monomeric state and helping to ensure stable plasmid inheritance. Despite its high similarity to ColE1 cer, the pJHCMW1 mwr was a poor substrate for Xer recombination in E. coli and did not contribute significantly to plasmid stability. Instead, the Tn1331 co-integrate resolution system was highly active at resolving pJHCMW1 multimers and ensured the stable inheritance of pJHCMW1. Although Xer recombination at pJHCMW1 mwr was inefficient in E. coli, the recombination that did occur was dependent on ArgR, PepA, XerC and XerD. A supercoiled circular DNA molecule containing two pJHCMW1 mwr sites in direct repeat yielded Holliday-junction-containing product when incubated with ArgR, PepA, XerC and XerD in vitro, confirming that pJHCMW1 mwr is a functional recombination site. However, unlike cer, some Holliday-junction-containing product could be detected for mwr in the absence of ArgR, although addition of this protein resulted in formation of more Holliday junctions. Binding experiments demonstrated that XerD bound to pJHCMW1 mwr core with a high affinity, but that XerC bound to this site very poorly, even in the presence of XerD.
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Affiliation(s)
- Marcelo E Tolmasky
- Institute of Molecular Biology and Nutrition, Department of Biological Science, School of Natural Science and Mathematics, California State University Fullerton, Fullerton, CA 92834-6850, USA2
- Microbiology Unit, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK1
| | - Sean Colloms
- Microbiology Unit, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK1
| | - Garry Blakely
- Microbiology Unit, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK1
| | - David J Sherratt
- Microbiology Unit, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK1
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Wu SW, Dornbusch K, Kronvall G, Norgren M. Characterization and nucleotide sequence of a Klebsiella oxytoca cryptic plasmid encoding a CMY-type beta-lactamase: confirmation that the plasmid-mediated cephamycinase originated from the Citrobacter freundii AmpC beta-lactamase. Antimicrob Agents Chemother 1999; 43:1350-7. [PMID: 10348751 PMCID: PMC89277 DOI: 10.1128/aac.43.6.1350] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Plasmid pTKH11, originally obtained by electroporation of a Klebsiella oxytoca plasmid preparation into Escherichia coli XAC, expressed a high level of an AmpC-like beta-lactamase. The enzyme, designated CMY-5, conferred resistance to extended-spectrum beta-lactams in E. coli; nevertheless, the phenotype was cryptic in the K. oxytoca donor. Determination of the complete nucleotide sequence of pTKH11 revealed that the 8,193-bp plasmid encoded seven open reading frames, including that for the CMY-5 beta-lactamase (blaCMY-5). The blaCMY-5 product was similar to the plasmidic CMY-2 beta-lactamase of K. pneumoniae and the chromosomal AmpC of Citrobacter freundii, with 99.7 and 97.0% identities, respectively; there was a substitution of phenylalanine in CMY-5 for isoleucine 105 in CMY-2. blaCMY-5 was followed by the Blc and SugE genes of C. freundii, and this cluster exhibited a genetic organization identical to that of the ampC region on the chromosome of C. freundii; these results confirmed that C. freundii AmpC was the evolutionary origin of the plasmidic cephamycinases. In the K. oxytoca host, the copy number of pTKH11 was very low and the plasmid coexisted with plasmid pNBL63. Analysis of the replication regions of the two plasmids revealed 97% sequence similarity in the RNA I transcripts; this result implied that the two plasmids might be incompatible. Incompatibility of the two plasmids might explain the cryptic phenotype of blaCMY-5 in K. oxytoca through an exclusion effect on pTKH11 by resident plasmid pNBL63.
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Affiliation(s)
- S W Wu
- Department of Laboratory Medicine, Division of Clinical Microbiology, Karolinska Institute and Karolinska Hospital, 171 76 Stockholm, Sweden.
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Panaite DM, Tolmasky ME. Characterization of mutants of the 6'-N-acetyltransferase encoded by the multiresistance transposon Tn1331: effect of Phen171-to-Leu171 and Tyr80-to-Cys80 substitutions. Plasmid 1998; 39:123-33. [PMID: 9514709 DOI: 10.1006/plas.1997.1330] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Klebsiella pneumoniae plasmid pJHCMW1 harbors a copy of Tn1331, a multiresistance transposon that includes the aac(6')-Ib gene which encodes a 6'-N-aminoglycoside acetyltransferase. This gene was mutagenized using the mutator Escherichia coli XL1-Red. Two plasmids with a single nucleotide mutation in aac(6')-Ib were selected for further analysis: pDP1 and pDP6. Plasmid pDP1 codes for a mutant enzyme, AAC(6')-IbDP1, that has the Phe171 replaced by a Leu residue. This mutant derivative showed a lower specific activity than the wild-type enzyme when either kanamycin (Km) or its semisynthetic derivative amikacin (Ak) were used as substrates in enzymatic assays performed at 30 degrees C. Furthermore, AAC(6')-IbDP1 showed a change of specificity of substrate when incubated at 42 degrees C. While its acetylating activity for Km was higher at this temperature than at 30 degrees C, it had its ability to utilize Ak as substrate for acetylation considerably reduced. Accordingly, minimal inhibitory concentration assays showed that E. coli(pDP1) was resistant to Ak at 37 degrees C but susceptible at 42 degrees C. The same assays showed that E. coli(pDP1) was highly resistant to Km at either 37 degrees C or 42 degrees C. A high level of resistance to Ak was observed for E. coli(pJHCMW1) which harbors the wild-type AAC(6')-Ib at either 37 or 42 degrees C. Extension of the analyses to other aminoglycosides showed that the enzymatic activity of AAC(6')-IbDP1 as well as the E. coli(pDP1) MICs for netilmicin dropped at 42 degrees C as was the case for Ak. These results could indicate that at 42 degrees C the mutant adopts a conformation that makes it unable to efficiently acetylate aminoglycoside molecules substituted in the C-1amino group of the deoxystreptamine moiety. Plasmid pDP6 encodes the mutant AAC(6')-IbDP6 which has the Tyr80 substituted by a Cys residue. E. coli(pDP6) exhibited reduced MICs for Ak, Km, tobramycin, and netilmicin. Analysis of the acetylating activity of AAC(6')-IbDP6 showed only marginal levels of activity when either Ak, Km, tobramycin, or netilmicin were used as substrates.
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Affiliation(s)
- D M Panaite
- Department of Biological Science, School of Natural Sciences and Mathematics, California State University Fullerton, California 92834-6850, USA
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