1
|
Leão PVS, Ferreira ALDS, Oliveira FADA, Mesquita ABDS, Lima-Net JDS, Gutierrez SJC, Nogueira CES, Cruz-Martins N, Arcanjo DDR, Barreto HM, Lima Ferreira JH. Riparin-B as a Potential Inhibitor of AdeABC Efflux System from Acinetobacter baumannii. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2023; 2023:1780838. [PMID: 37089710 PMCID: PMC10118900 DOI: 10.1155/2023/1780838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 01/07/2023] [Accepted: 02/02/2023] [Indexed: 04/25/2023]
Abstract
Acinetobacter baumannii is an important opportunistic pathogen that causes serious health-related infections, especially in intensive care units. The present study aimed to investigate the antimicrobial activity of Riparin-B (Rip-B) alone and in association with norfloxacin against multidrug-resistant clinical isolates of A. baumannii. For this, the minimum inhibitory concentrations were determined by the microdilution method. For the evaluation of resistance-modulating activity, MIC values for antibiotics were determined in the presence or absence of subinhibitory concentrations of Rip-B or chlorpromazine (CPZ). The AdeABC-AdeRS efflux system genes from these isolates were detected by PCR. Docking studies were also carried out to evaluate the interaction of Riparin-B and the AdeABC-AdeRS efflux system. The study was conducted from 2017 to 2019. The results showed that Rip-B showed weak intrinsic activity against the strains tested. On the other hand, Rip-B was able to modulate norfloxacin's response against A. baumannii strains that express efflux pump-mediated resistance. Docking studies provided projections of the interaction between Rip-B and EtBr with the AdeB protein, suggesting that Rip-B acts by competitive inhibition with the drug. Results found by in vitro and in silico assays suggest that Rip-B, in combination with norfloxacin, has the potential to treat infections caused by multidrug-resistant A. baumanni with efflux pump resistance.
Collapse
Affiliation(s)
- Patrícia Virna Sales Leão
- Laboratory of Research in Microbiology, Department of Parasitology and Microbiology, Federal University of Piaui, Teresina, Piauí, Brazil
| | - Ana Laura da Silva Ferreira
- Laboratory of Research in Microbiology, Department of Parasitology and Microbiology, Federal University of Piaui, Teresina, Piauí, Brazil
| | | | - Avilnete Belém de Souza Mesquita
- Laboratory of Research in Microbiology, Department of Parasitology and Microbiology, Federal University of Piaui, Teresina, Piauí, Brazil
| | | | | | | | - Natália Cruz-Martins
- Faculty of Medicine, University of Porto, Alameda Prof. Hernâni Monteiro, Porto 4200-319, Portugal
- Institute for Research and Innovation in Health (i3S), University of Porto, Porto 4200-135, Portugal
| | - Daniel Dias Rufino Arcanjo
- Laboratory of Functional and Molecular Studies on Physiopharmacology (LAFMOL), Department of Biophysics and Physiology, Federal University of Piaui, Teresina, Piauí, Brazil
| | - Humberto Medeiros Barreto
- Laboratory of Research in Microbiology, Department of Parasitology and Microbiology, Federal University of Piaui, Teresina, Piauí, Brazil
| | - Josie Haydée Lima Ferreira
- Laboratory of Research in Microbiology, Department of Parasitology and Microbiology, Federal University of Piaui, Teresina, Piauí, Brazil
| |
Collapse
|
2
|
A prospective matched case-control study on the genomic epidemiology of colistin-resistant Enterobacterales from Dutch patients. COMMUNICATIONS MEDICINE 2022; 2:55. [PMID: 35607432 PMCID: PMC9122983 DOI: 10.1038/s43856-022-00115-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 04/20/2022] [Indexed: 11/08/2022] Open
Abstract
Abstract
Background
Colistin is a last-resort treatment option for infections with multidrug-resistant Gram-negative bacteria. However, colistin resistance is increasing.
Methods
A six-month prospective matched case-control study was performed in which 22 Dutch laboratories with 32 associated hospitals participated. Laboratories were invited to send a maximum of five colistin-resistant Escherichia coli or Klebsiella pneumoniae (COLR-EK) isolates and five colistin-susceptible isolates (COLS-EK) to the reference laboratory, matched for patient location, material of origin and bacterial species. Epidemiological/clinical data were collected and included in the analysis. Characteristics of COLR-EK/COLS-EK isolates were compared using logistic regression with correction for variables used for matching. Forty-six ColR-EK/ColS-EK pairs were analysed by next-generation sequencing (NGS) for whole-genome multi-locus sequence typing and identification of resistance genes, including mcr genes. To identify chromosomal mutations potentially leading to colistin resistance, NGS reads were mapped against gene sequences of pmrAB, phoPQ, mgrB and crrB.
Results
In total, 72 COLR-EK/COLS-EK pairs (75% E. coli and 25% K. pneumoniae) were included. Twenty-one percent of COLR-EK patients had received colistin, in contrast to 3% of COLS-EK patients (OR > 2.9). Of COLR-EK isolates, five contained mcr-1 and two mcr-9. One isolate lost mcr-9 after repeated sub-culturing, but retained colistin resistance. Among 46 sequenced COLR-EK isolates, genetic diversity was large and 19 (41.3%) isolates had chromosomal mutations potentially associated with colistin resistance.
Conclusions
Colistin resistance is present but uncommon in the Netherlands and caused by the mcr gene in a minority of COLR-EK isolates. There is a need for surveillance of colistin resistance using appropriate susceptibility testing methods.
Collapse
|
3
|
The Role of Colistin in the Era of New β-Lactam/β-Lactamase Inhibitor Combinations. Antibiotics (Basel) 2022; 11:antibiotics11020277. [PMID: 35203879 PMCID: PMC8868358 DOI: 10.3390/antibiotics11020277] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/17/2022] [Accepted: 02/17/2022] [Indexed: 02/06/2023] Open
Abstract
With the current crisis related to the emergence of carbapenem-resistant Gram-negative bacteria (CR-GNB), classical treatment approaches with so-called “old-fashion antibiotics” are generally unsatisfactory. Newly approved β-lactam/β-lactamase inhibitors (BLBLIs) should be considered as the first-line treatment options for carbapenem-resistant Enterobacterales (CRE) and carbapenem-resistant Pseudomonas aeruginosa (CRPA) infections. However, colistin can be prescribed for uncomplicated lower urinary tract infections caused by CR-GNB by relying on its pharmacokinetic and pharmacodynamic properties. Similarly, colistin can still be regarded as an alternative therapy for infections caused by carbapenem-resistant Acinetobacter baumannii (CRAB) until new and effective agents are approved. Using colistin in combination regimens (i.e., including at least two in vitro active agents) can be considered in CRAB infections, and CRE infections with high risk of mortality. In conclusion, new BLBLIs have largely replaced colistin for the treatment of CR-GNB infections. Nevertheless, colistin may be needed for the treatment of CRAB infections and in the setting where the new BLBLIs are currently unavailable. In addition, with the advent of rapid diagnostic methods and novel antimicrobials, the application of personalized medicine has gained significant importance in the treatment of CRE infections.
Collapse
|
4
|
Murtha AN, Kazi MI, Schargel RD, Cross T, Fihn C, Cattoir V, Carlson EE, Boll JM, Dörr T. High-level carbapenem tolerance requires antibiotic-induced outer membrane modifications. PLoS Pathog 2022; 18:e1010307. [PMID: 35130322 PMCID: PMC8853513 DOI: 10.1371/journal.ppat.1010307] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 02/17/2022] [Accepted: 01/26/2022] [Indexed: 12/22/2022] Open
Abstract
Antibiotic tolerance is an understudied potential contributor to antibiotic treatment failure and the emergence of multidrug-resistant bacteria. The molecular mechanisms governing tolerance remain poorly understood. A prominent type of β-lactam tolerance relies on the formation of cell wall-deficient spheroplasts, which maintain structural integrity via their outer membrane (OM), an asymmetric lipid bilayer consisting of phospholipids on the inner leaflet and a lipid-linked polysaccharide (lipopolysaccharide, LPS) enriched in the outer monolayer on the cell surface. How a membrane structure like LPS, with its reliance on mere electrostatic interactions to maintain stability, is capable of countering internal turgor pressure is unknown. Here, we have uncovered a novel role for the PhoPQ two-component system in tolerance to the β-lactam antibiotic meropenem in Enterobacterales. We found that PhoPQ is induced by meropenem treatment and promotes an increase in 4-amino-4-deoxy-L-aminoarabinose [L-Ara4N] modification of lipid A, the membrane anchor of LPS. L-Ara4N modifications likely enhance structural integrity, and consequently tolerance to meropenem, in several Enterobacterales species. Importantly, mutational inactivation of the negative PhoPQ regulator mgrB (commonly selected for during clinical therapy with the last-resort antibiotic colistin, an antimicrobial peptide [AMP]) results in dramatically enhanced tolerance, suggesting that AMPs can collaterally select for meropenem tolerance via stable overactivation of PhoPQ. Lastly, we identify histidine kinase inhibitors (including an FDA-approved drug) that inhibit PhoPQ-dependent LPS modifications and consequently potentiate meropenem to enhance lysis of tolerant cells. In summary, our results suggest that PhoPQ-mediated LPS modifications play a significant role in stabilizing the OM, promoting survival when the primary integrity maintenance structure, the cell wall, is removed. Treating an infection with an antibiotic often fails, resulting in a tremendous public health burden. One understudied likely reason for treatment failure is the development of “antibiotic tolerance”, the ability of bacteria to survive normally lethal exposure to an antibiotic. Here, we describe a molecular mechanism promoting tolerance. A bacterial stress sensor (PhoPQ) is activated in response to antibiotic (meropenem) treatment and consequently strengthens a bacterial protective “shell” to enhance survival. We also identify inhibitors of this mechanism, opening the door to developing compounds that help antibiotics work better against tolerant bacteria.
Collapse
Affiliation(s)
- Andrew N. Murtha
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, United States of America
- Department of Microbiology, Cornell University, Ithaca, New York, United States of America
| | - Misha I. Kazi
- Department of Biology, University of Texas Arlington, Arlington, Texas, United States of America
| | - Richard D. Schargel
- Department of Biology, University of Texas Arlington, Arlington, Texas, United States of America
| | - Trevor Cross
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, United States of America
- Department of Microbiology, Cornell University, Ithaca, New York, United States of America
| | - Conrad Fihn
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Vincent Cattoir
- Department of Clinical Microbiology and National Reference Center for Antimicrobial Resistance (Lab Enterococci), Rennes University Hospital, Rennes, France; Inserm Unit U1230, University of Rennes 1, Rennes, France
| | - Erin E. Carlson
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota, United States of America
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota, United States of America
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, United States of America
- Department of Molecular Pharmacology and Therapeutics, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Joseph M. Boll
- Department of Biology, University of Texas Arlington, Arlington, Texas, United States of America
- * E-mail: (JMB); (TD)
| | - Tobias Dörr
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, United States of America
- Department of Microbiology, Cornell University, Ithaca, New York, United States of America
- Cornell Institute of Host-Microbe Interactions and Disease, Cornell University, Ithaca, New York, United States of America
- * E-mail: (JMB); (TD)
| |
Collapse
|
5
|
Lane CR, Brett J, Schultz M, Gorrie CL, Stevens K, Cameron DRM, St George S, van Diemen A, Easton M, Stuart RL, Sait M, Peleg AY, Stewardson AJ, Cheng AC, Spelman DW, Waters MJ, Ballard SA, Sherry NL, Williamson DA, Romanes F, Sutton B, Kwong JC, Seemann T, Goncalves da Silva A, Stephens N, Howden BP. Search and Contain: Impact of an Integrated Genomic and Epidemiological Surveillance and Response Program for Control of Carbapenemase-producing Enterobacterales. Clin Infect Dis 2021; 73:e3912-e3920. [PMID: 32663248 PMCID: PMC8662772 DOI: 10.1093/cid/ciaa972] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 07/08/2020] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Multiresistant organisms (MROs) pose a critical threat to public health. Population-based programs for control of MROs such as carbapenemase-producing Enterobacterales (CPE) have emerged and evaluation is needed. We assessed the feasibility and impact of a statewide CPE surveillance and response program deployed across Victoria, Australia (population 6.5 million). METHODS A prospective multimodal intervention including active screening, carrier isolation, centralized case investigation, and comparative pathogen genomics was implemented. We analyzed trends in CPE incidence and clinical presentation, risk factors, and local transmission over the program's first 3 years (2016-2018). RESULTS CPE case ascertainment increased over the study period to 1.42 cases/100 000 population, linked to increased screening without a concomitant rise in active clinical infections (0.45-0.60 infections/100 000 population, P = .640). KPC-2 infection decreased from 0.29 infections/100 000 population prior to intervention to 0.03 infections/100 000 population in 2018 (P = .003). Comprehensive case investigation identified instances of overseas community acquisition. Median time between isolate referral and genomic and epidemiological assessment for local transmission was 11 days (IQR, 9-14). Prospective surveillance identified numerous small transmission networks (median, 2; range, 1-19 cases), predominantly IMP and KPC, with median pairwise distance of 8 (IQR, 4-13) single nucleotide polymorphisms; low diversity between clusters of the same sequence type suggested genomic cluster definitions alone are insufficient for targeted response. CONCLUSIONS We demonstrate the value of centralized CPE control programs to increase case ascertainment, resolve risk factors, and identify local transmission through prospective genomic and epidemiological surveillance; methodologies are transferable to low-prevalence settings and MROs globally.
Collapse
Affiliation(s)
- Courtney R Lane
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
- Department of Microbiology & Immunology, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
| | - Judith Brett
- VICNISS Healthcare Associated Infection Surveillance Coordinating Centre, at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
| | - Mark Schultz
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
- Department of Microbiology & Immunology, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
| | - Claire L Gorrie
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
- Department of Microbiology & Immunology, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
| | - Kerrie Stevens
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
| | - Donna R M Cameron
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
- Department of Health and Human Services, Victorian Government, Melbourne, Victoria, Australia
| | - Siobhan St George
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
| | - Annaliese van Diemen
- Department of Health and Human Services, Victorian Government, Melbourne, Victoria, Australia
| | - Marion Easton
- Department of Health and Human Services, Victorian Government, Melbourne, Victoria, Australia
| | - Rhonda L Stuart
- Monash Infectious Diseases, Monash Health, Monash Medical Centre, Clayton, Victoria, Australia
| | - Michelle Sait
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
| | - Anton Y Peleg
- Department of Infectious Diseases, Alfred Hospital, and Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Andrew J Stewardson
- Department of Infectious Diseases, Alfred Hospital, and Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Allen C Cheng
- Department of Infectious Diseases, Alfred Hospital, and Central Clinical School, Monash University, Melbourne, Victoria, Australia
- School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Denis W Spelman
- Department of Infectious Diseases, Alfred Hospital, and Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Department of Microbiology, The Alfred Hospital, Melbourne, Victoria, Australia
| | - Mary Jo Waters
- Department of Microbiology, St Vincent’s Hospital Melbourne, Fitzroy, Victoria, Australia
| | - Susan A Ballard
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
| | - Norelle L Sherry
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
- Department of Microbiology & Immunology, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
- Department of Infectious Diseases, Austin Health, Heidelberg, Victoria, Australia
| | - Deborah A Williamson
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
| | - Finn Romanes
- Department of Health and Human Services, Victorian Government, Melbourne, Victoria, Australia
| | - Brett Sutton
- Department of Health and Human Services, Victorian Government, Melbourne, Victoria, Australia
| | - Jason C Kwong
- Department of Microbiology & Immunology, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
- Department of Infectious Diseases, Austin Health, Heidelberg, Victoria, Australia
| | - Torsten Seemann
- Department of Microbiology & Immunology, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
| | - Anders Goncalves da Silva
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
- Department of Microbiology & Immunology, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
| | - Nicola Stephens
- Department of Microbiology & Immunology, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
- Department of Health and Human Services, Victorian Government, Melbourne, Victoria, Australia
- University of Tasmania, Hobart, Tasmania, Australia
| | - Benjamin P Howden
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
- Department of Microbiology & Immunology, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria, Australia
- Department of Infectious Diseases, Austin Health, Heidelberg, Victoria, Australia
| |
Collapse
|
6
|
Gogry FA, Siddiqui MT, Sultan I, Haq QMR. Current Update on Intrinsic and Acquired Colistin Resistance Mechanisms in Bacteria. Front Med (Lausanne) 2021; 8:677720. [PMID: 34476235 PMCID: PMC8406936 DOI: 10.3389/fmed.2021.677720] [Citation(s) in RCA: 89] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 07/09/2021] [Indexed: 01/07/2023] Open
Abstract
Colistin regained global interest as a consequence of the rising prevalence of multidrug-resistant Gram-negative Enterobacteriaceae. In parallel, colistin-resistant bacteria emerged in response to the unregulated use of this antibiotic. However, some Gram-negative species are intrinsically resistant to colistin activity, such as Neisseria meningitides, Burkholderia species, and Proteus mirabilis. Most identified colistin resistance usually involves modulation of lipid A that decreases or removes early charge-based interaction with colistin through up-regulation of multistep capsular polysaccharide expression. The membrane modifications occur by the addition of cationic phosphoethanolamine (pEtN) or 4-amino-l-arabinose on lipid A that results in decrease in the negative charge on the bacterial surface. Therefore, electrostatic interaction between polycationic colistin and lipopolysaccharide (LPS) is halted. It has been reported that these modifications on the bacterial surface occur due to overexpression of chromosomally mediated two-component system genes (PmrAB and PhoPQ) and mutation in lipid A biosynthesis genes that result in loss of the ability to produce lipid A and consequently LPS chain, thereafter recently identified variants of plasmid-borne genes (mcr-1 to mcr-10). It was hypothesized that mcr genes derived from intrinsically resistant environmental bacteria that carried chromosomal pmrC gene, a part of the pmrCAB operon, code three proteins viz. pEtN response regulator PmrA, sensor kinase protein PmrAB, and phosphotransferase PmrC. These plasmid-borne mcr genes become a serious concern as they assist in the dissemination of colistin resistance to other pathogenic bacteria. This review presents the progress of multiple strategies of colistin resistance mechanisms in bacteria, mainly focusing on surface changes of the outer membrane LPS structure and other resistance genetic determinants. New handier and versatile methods have been discussed for rapid detection of colistin resistance determinants and the latest approaches to revert colistin resistance that include the use of new drugs, drug combinations and inhibitors. Indeed, more investigations are required to identify the exact role of different colistin resistance determinants that will aid in developing new less toxic and potent drugs to treat bacterial infections. Therefore, colistin resistance should be considered a severe medical issue requiring multisectoral research with proper surveillance and suitable monitoring systems to report the dissemination rate of these resistant genes.
Collapse
Affiliation(s)
| | | | - Insha Sultan
- Department of Biosciences, Jamia Millia Islamia, New Delhi, India
| | | |
Collapse
|
7
|
Ben-Chetrit E, Mc Gann P, Maybank R, Stam J, Assous MV, Katz DE. Colistin-resistant Klebsiella pneumoniae bloodstream infection: old drug, bad bug. Arch Microbiol 2021; 203:2999-3006. [PMID: 33774687 DOI: 10.1007/s00203-021-02289-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 03/14/2021] [Accepted: 03/16/2021] [Indexed: 11/24/2022]
Abstract
Multi-drug-resistant (MDR) Enterobacteriaceae pose a global threat to hospitalized patients. We report a series of colistin-resistant Klebsiella pneumoniae blood isolates from Israel and explore their resistance mechanisms using whole genome sequencing (WGS). Patients with colistin-resistant K. pneumoniae bloodstream infection (BSI) were identified during the period between 2006 and 2018. Demographic and clinical data were collected, and antibiotic susceptibility testing (AST) was performed using three commercial platforms. Long and short read sequencing were performed on a PacBio RS II (Pacific Biosciences) and an Illumina Miseq (Illumina), respectively. Thirteen patients with colistin-resistant K. pneumoniae BSI were identified, and seven isolates from seven different patients were successfully revived. Patient records indicated that five of the patients were previously treated with colistin. AST indicated that six of the seven isolates were colistin resistant and four of these isolates were resistant to carbapenems. WGS assigned the isolates to four distinct clusters that corresponded to in silico-derived multi-locus sequence types (MLST). Three isolates carried blaKPC-3 on two different plasmids and one carried blaOXA-48 on a novel IncL/M plasmid. All colistin-resistant isolates carried a variety of different mutations that inactivated the mgrB gene. We report the first comprehensive analysis of a series of colistin-resistant K. pneumoniae from Israel. A diverse set of isolates were obtained and colistin resistance was found to be attributed to different mechanisms that ablated the mgrB gene. Notably, carbapenemase genes were identified in four isolates and were carried on novel plasmids.
Collapse
Affiliation(s)
- Eli Ben-Chetrit
- Shaare Zedek Medical Center, Department of Infectious Diseases, Jerusalem, Israel.,Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Patrick Mc Gann
- Multidrug-Resistant Organism Repository and Surveillance Network (MRSN), Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Rosslyn Maybank
- Multidrug-Resistant Organism Repository and Surveillance Network (MRSN), Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Jason Stam
- Multidrug-Resistant Organism Repository and Surveillance Network (MRSN), Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Marc V Assous
- Shaare Zedek Medical Center, Department of Microbiology, Jerusalem, Israel
| | - David E Katz
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel. .,Shaare Zedek Medical Center, Division of Internal Medicine, Jerusalem, Israel.
| |
Collapse
|
8
|
Colistin Update on Its Mechanism of Action and Resistance, Present and Future Challenges. Microorganisms 2020; 8:microorganisms8111716. [PMID: 33147701 PMCID: PMC7692639 DOI: 10.3390/microorganisms8111716] [Citation(s) in RCA: 92] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/26/2020] [Accepted: 10/30/2020] [Indexed: 02/07/2023] Open
Abstract
Colistin has been extensively used since the middle of the last century in animals, particularly in swine, for the control of enteric infections. Colistin is presently considered the last line of defense against human infections caused by multidrug-resistant Gram-negative organisms such as carbapenemase-producer Enterobacterales, Acinetobacter baumanni, and Pseudomonas aeruginosa. Transferable bacterial resistance like mcr-genes was reported in isolates from both humans and animals. Researchers actively seek strategies to reduce colistin resistance. The definition of guidelines for colistin therapy in veterinary and human medicine is thus crucial. The ban of colistin use in swine as a growth promoter and for prophylactic purposes, and the implementation of sustainable measures in farm animals for the prevention of infections, would help to avoid resistance and should be encouraged. Colistin resistance in the human-animal-environment interface stresses the relevance of the One Health approach to achieve its effective control. Such measures should be addressed in a cooperative way, with efforts from multiple disciplines and with consensus among doctors, veterinary surgeons, and environment professionals. A revision of the mechanism of colistin action, resistance, animal and human use, as well as colistin susceptibility evaluation is debated here.
Collapse
|
9
|
Cheung CHP, Dulyayangkul P, Heesom KJ, Avison MB. Proteomic Investigation of the Signal Transduction Pathways Controlling Colistin Resistance in Klebsiella pneumoniae. Antimicrob Agents Chemother 2020; 64:AAC.00790-20. [PMID: 32457105 PMCID: PMC7526815 DOI: 10.1128/aac.00790-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 05/19/2020] [Indexed: 12/15/2022] Open
Abstract
Colistin resistance in Klebsiella pneumoniae is predominantly caused by mutations that increase expression of the arn (also known as pbg or pmrF) operon. Expression is activated by the PhoPQ and PmrAB two-component systems. Constitutive PhoPQ activation occurs directly by mutation or following loss of MgrB. PhoPQ may also cross-activate PmrAB via the linker protein PmrD. Using proteomics, we show that MgrB loss causes a wider proteomic effect than direct PhoPQ activation, suggesting additional targets for MgrB. Different mgrB mutations cause different amounts of Arn protein production, which correlated with colistin MICs. Disruption of phoP in an mgrB mutant had a reciprocal effect to direct activation of PhoQ in a wild-type background, but the regulated proteins showed almost total overlap. Disruption of pmrD or pmrA slightly reduced Arn protein production in an mgrB mutant, but production was still high enough to confer colistin resistance; disruption of phoP conferred wild-type Arn production and colistin MIC. Activation of PhoPQ directly or through mgrB mutation did not significantly activate PmrAB or PmrC production, but direct activation of PmrAB by mutation was able to do this, and also activated Arn production and conferred colistin resistance. There was little overlap between the PmrAB and PhoPQ regulons. We conclude that under the conditions used for colistin susceptibility testing, PhoPQ-PmrD-PmrAB cross-regulation is not significant and that independent activation of PhoPQ or PmrAB is the main reason that Arn protein production increases above the threshold required for colistin resistance.
Collapse
Affiliation(s)
| | - Punyawee Dulyayangkul
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom
| | - Kate J Heesom
- University of Bristol Proteomics Facility, Bristol, United Kingdom
| | - Matthew B Avison
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom
| |
Collapse
|
10
|
Choi M, Ko KS. Identification of Genetic Alterations Associated with Acquired Colistin Resistance in Klebsiella pneumoniae Isogenic Strains by Whole-Genome Sequencing. Antibiotics (Basel) 2020; 9:antibiotics9070374. [PMID: 32630683 PMCID: PMC7400116 DOI: 10.3390/antibiotics9070374] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 06/25/2020] [Accepted: 06/30/2020] [Indexed: 11/16/2022] Open
Abstract
The present study was undertaken to find novel genes associated with colistin resistance in Klebsiella pneumoniae. Five colistin-resistant mutants were derived from four colistin-susceptible parental K. pneumoniae strains belonging to different clones. Whole-genome sequencing was performed for the nine K. pneumoniae strains to screen altered candidate genes. Expression levels of genes with amino acid alterations in derivative strains were determined using quantitative real-time Polymerase chain reaction (PCR). Colistin susceptibility was examined in a parental strain complemented with altered candidate genes. Overall, 13 genetic alterations were identified in five pairs of isogenic K. pneumoniae strains. Genetic alterations related to KP1_3468, including the insertion of an IS5-like element in an intergenic or coding region and amino acid substitutions, were identified in three separate derivative strains. Amino acid substitutions and deletion of PhoQ were determined in one derivative strain. With inactivation of CrrA and substituted CrrB, amino acid substitutions and deletion were identified in a repressor of galETK operon (KP1_0061) and hypothetical protein (KP1_3620), respectively. Decreased colistin susceptibility was observed in a parental strain complemented with KP1-0061, but not a KP1-3620 gene. This study demonstrated diverse genetic paths to colistin resistance in K. pneumoniae. Our results suggest that a repressor of galETK operon may play an important role in colistin resistance in K. pneumoniae.
Collapse
Affiliation(s)
| | - Kwan Soo Ko
- Correspondence: ; Tel.: +82-31-299-6223; Fax: +82-31-299-6229
| |
Collapse
|
11
|
Di Tella D, Tamburro M, Guerrizio G, Fanelli I, Sammarco ML, Ripabelli G. Molecular Epidemiological Insights into Colistin-Resistant and Carbapenemases-Producing Clinical Klebsiella pneumoniae Isolates. Infect Drug Resist 2019; 12:3783-3795. [PMID: 31819559 PMCID: PMC6899070 DOI: 10.2147/idr.s226416] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 10/02/2019] [Indexed: 01/09/2023] Open
Abstract
Purpose Carbapenemases-producing Klebsiella pneumoniae are challenging antimicrobial therapy of hospitalised patients, which is further complicated by colistin resistance. This study describes molecular epidemiological insights into colistin-resistant and carbapenemases-producing clinical K. pneumoniae. Patients and methods Cultures collected from 26 hospitalised patients during 2014-2017 in the main hospital in Molise Region, central Italy, were characterized. The minimum inhibitory concentration for 19 antibiotics was determined, including carbapenems and colistin. Prevalence of resistance-associated genes was investigated through PCR, detecting bla KPC, bla GES, bla VIM, bla IMP, bla NDM, bla OXA-48, bla CTX-M, bla TEM, bla SHV, and mcr-1,2,3,4,5,6,7,8. The mgrB gene was also analysed in colistin-resistant strains by PCR and sequencing assays. K. pneumoniae were typed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Results Twenty out of 26 K. pneumoniae were phenotypically resistant to carbapenems and 19 were resistant to colistin. All isolates harbored bla KPC, and bla SHV, bla TEM and bla VIM were further the most common resistance-associated genes. In colistin-resistant strains, mcr-1,2,3,4,5,6,7,8 variants were not detected, while mutations and insertion elements in mgrB were observed in 68.4% (n=13) in 31.6% (n=6) isolates, respectively. PFGE revealed 12 clusters and 18 pulsotypes at 85% and 95% cut-off, while the Sequence Types ST512 (n=13, 50%), ST101 (n=10, 38.5%), ST307 (n=2, 7.7%) plus a novel ST were detected using MLST. Conclusion All K. pneumoniae showed a multidrug-resistant phenotype, particularly to carbapenems and colistin. According to national data, bla KPC was the prevailing carbapenemase, followed by bla VIM, while bla TEM and bla SHV were among the most frequent beta-lactamases. Consistent with previous reports in Italy, ST512 was the most common clone, particularly during 2014-15, whilst ST101 became dominant in 2016-17. Colistin resistance was mainly associated with deleterious mutations and transposon in the mgrB gene. Improvements of surveillance, compliance with infection prevention procedures and antimicrobial stewardship are essential to limit the spread of resistant K. pneumoniae.
Collapse
Affiliation(s)
- Domiziana Di Tella
- Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, Campobasso, Italy
| | - Manuela Tamburro
- Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, Campobasso, Italy
| | - Giuliana Guerrizio
- Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, Campobasso, Italy
| | - Incoronata Fanelli
- Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, Campobasso, Italy
| | - Michela Lucia Sammarco
- Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, Campobasso, Italy
| | - Giancarlo Ripabelli
- Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, Campobasso, Italy
| |
Collapse
|
12
|
Tian X, Huang C, Ye X, Jiang H, Zhang R, Hu X, Xu D. Molecular Epidemiology of and Risk Factors for Extensively Drug-Resistant Klebsiella pneumoniae Infections in Southwestern China: A Retrospective Study. Front Pharmacol 2019; 10:1307. [PMID: 31736765 PMCID: PMC6838015 DOI: 10.3389/fphar.2019.01307] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 10/15/2019] [Indexed: 12/23/2022] Open
Abstract
Background: The increasing prevalence of extensively drug-resistant Klebsiella pneumoniae (XDR-KP) poses a serious threat to clinical anti-infective treatment. This retrospective study assessed the molecular epidemiology of and risk factors for infections with XDR-KP to investigate the mechanism of drug resistance and the epidemiological characteristics. Methods: A retrospective 1:2 case-control study was conducted at Chongqing Renji Affiliated Hospital of the Chinese Academy of Sciences University from January 2015 to December 2017. A total of 69 non-repetitive XDR-KP strains were collected. Patients infected with XDR-KP comprised the case group, and 138 matched patients with non-XDR-KP infection at the same site comprised the control group. The chi-square test and logistic regression were performed to evaluate the related risk factors. Molecular typing was performed by multilocus sequence typing (MLST). Potential resistance genes were detected by polymerase chain reaction (PCR) and sequencing. Predictors of 28-day mortality in patients with XDR-KP infection were also identified in our study. Results: Only tigecycline and polymyxin B showed favorable in vitro drug sensitivity tests. These XDR-KP strains had a high prevalence rate (n = 66, 95.7%) of carbapenemase-related drug resistance genes. Among them, KPC-2 was the most frequently detected gene (n = 52, 75.4%). Particularly, all of the isolates harbored multiple drug resistance genes. Epidemiological analysis showed that fifty-eight XDR-KP isolates were resistant strains with the ST-11 genotype. Multivariate logistic regression analysis showed that ICU admission (OR: 3.28, 95% CI: 1.66–6.49, P < 0.001), tracheal cannula (OR: 3.16, 95% CI: 1.48–6.76, P = 0.003), and carbapenem exposure (OR: 3.16, 95% CI: 1.25–7.98, P = 0.015) were independent risk factors for XDR-KP infection. Solid tumors (OR: 7.22, 95% CI: 1.84–28.34, P = 0.005) and septic shock (OR: 9.46, 95% CI: 2.00–44.72, P = 0.005) were independent risk factors for 28-day mortality from XDR-KP infection. Conclusion: This study showed that XDR-KP isolates were highly resistant and exhibited clonal transmission. ST11 was the predominant epidemic type of XDR-KP producing KPC-2 in Southwestern China. Physicians should be aware of these high-risk patients with notable predictive factors for XDR-KP infection. These findings may provide some recommendation for the diagnosis and treatment of patients infected with XDR-KP strains in Southwestern China.
Collapse
Affiliation(s)
- Xiaolang Tian
- Department of Clinical Laboratory, University of Chinese Academy of Sciences Chongqing Renji Hospital, Fifth People's Hospital of Chongqing, Chongqing, China
| | - Changwu Huang
- Department of Clinical Laboratory, University of Chinese Academy of Sciences Chongqing Renji Hospital, Fifth People's Hospital of Chongqing, Chongqing, China
| | - Xiaoli Ye
- Department of Clinical Laboratory, University of Chinese Academy of Sciences Chongqing Renji Hospital, Fifth People's Hospital of Chongqing, Chongqing, China
| | - Hongyan Jiang
- Department of Clinical Laboratory, University of Chinese Academy of Sciences Chongqing Renji Hospital, Fifth People's Hospital of Chongqing, Chongqing, China
| | - Rufang Zhang
- Department of Clinical Laboratory, University of Chinese Academy of Sciences Chongqing Renji Hospital, Fifth People's Hospital of Chongqing, Chongqing, China
| | - Xiaofang Hu
- Department of Clinical Laboratory, University of Chinese Academy of Sciences Chongqing Renji Hospital, Fifth People's Hospital of Chongqing, Chongqing, China
| | - Dongshuang Xu
- Department of Clinical Laboratory, University of Chinese Academy of Sciences Chongqing Renji Hospital, Fifth People's Hospital of Chongqing, Chongqing, China
| |
Collapse
|
13
|
Yap PSX, Ahmad Kamar A, Chong CW, Ngoi ST, Teh CSJ. Genomic Insights into Two Colistin-Resistant Klebsiella pneumoniae Strains Isolated from the Stool of Preterm Neonate During the First Week of Life. Microb Drug Resist 2019; 26:190-203. [PMID: 31545116 DOI: 10.1089/mdr.2019.0199] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Background: Klebsiella pneumoniae is a major opportunistic pathogen frequently associated with nosocomial infections, and often poses a major threat to immunocompromised patients. In our previous study, two K. pneumoniae (K36 and B13), which displayed resistance to almost all major antibiotics, including colistin, were isolated. Both isolates were not associated with infection and isolated from the stools of two preterm neonates admitted to the neonatal intensive care unit (NICU) during their first week of life. Materials and Methods: In this study, whole genome sequencing was performed on these two clinical multidrug resistant K. pneumoniae. We aimed to determine the genetic factors that underline the antibiotic-resistance phenotypes of these isolates. Results: The strains harbored blaSHV-27, blaSHV-71, and oqxAB genes conferring resistance to cephalosporins, carbapenems, and fluoroquinolones, respectively, but not harboring any known plasmid-borne colistin resistance determinants such as mcr-1. However, genome analysis discovered interruption of mgrB gene by insertion sequences gaining insight into the development of colistin resistance. Conclusion: The observed finding that points to a scenario of potential gut-associated resistance genes to Gram negative (K. pneumoniae) host in the NICU environment warrants attention and further investigation.
Collapse
Affiliation(s)
- Polly Soo Xi Yap
- Department of Medical Microbiology and Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Azanna Ahmad Kamar
- Department of Paediatrics, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Chun Wie Chong
- School of Pharmacy, Monash University, Jalan Lagoon Selatan, Selangor, Malaysia
| | - Soo Tein Ngoi
- Department of Medical Microbiology and Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Cindy Shuan Ju Teh
- Department of Medical Microbiology and Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| |
Collapse
|
14
|
Xu J, Li T, Gao Y, Deng J, Gu J. MgrB affects the acid stress response of Escherichia coli by modulating the expression of iraM. FEMS Microbiol Lett 2019; 366:fnz123. [PMID: 31158277 DOI: 10.1093/femsle/fnz123] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 06/01/2019] [Indexed: 10/18/2023] Open
Abstract
Although MgrB is established to be a feedback inhibitor of the PhoP/Q system in Escherichia coli, the biological functions of MgrB remain largely unknown. To explore new functions of MgrB, a comparative transcriptome analysis was performed (E. coli K-12 W3110 ΔmgrB vs E. coli K-12 W3110). The results showed that many genes involved in acid stress are upregulated, suggesting that MgrB is related to acid sensitivity in E. coli. The survival rates under acid stress of the ΔmgrB mutant and wild-type showed that deletion of mgrB resulted in acid resistance. According to previous research, we deleted phoP, phoQ and iraM in the ΔmgrB mutant, and found that further deletion of phoP/phoQ only partially restored acid sensitivity. Additionally, we found that deletion of mgrB resulted in increased accumulation of RpoS during the exponential growth phase, which could be blocked by further deletion of iraM. Mutation of iraM or rpoS completely suppressed the effect of mgrB mutation on acid resistance. Taken together, the data suggest that MgrB affects the acid resistance of E. coli by modulating the expression of iraM, but not completely through PhoP/Q. This indicates that MgrB may have other protein interactors aside from PhoQ, which merits further investigation.
Collapse
Affiliation(s)
- Jintian Xu
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Ting Li
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Yunrong Gao
- The Joint Center of Translational Precision Medicine, Guangzhou Institute of Pediatrics, Guangzhou Women and Children Medical Center, Guangzhou 510623, China
| | - Jiaoyu Deng
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
- Guangdong Province Key Laboratory of TB Systems Biology and Translational Medicine, Foshan Institude of Industrial Technology, Chinese Academic of Sciences, Foshan 528000, China
| | - Jing Gu
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| |
Collapse
|
15
|
France MT, Cornea A, Kehlet‐Delgado H, Forney LJ. Spatial structure facilitates the accumulation and persistence of antibiotic-resistant mutants in biofilms. Evol Appl 2019; 12:498-507. [PMID: 30828370 PMCID: PMC6383844 DOI: 10.1111/eva.12728] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 09/16/2018] [Accepted: 10/02/2018] [Indexed: 01/13/2023] Open
Abstract
The emergence and spread of antibiotic resistance in bacterial pathogens are a global crisis. Because many bacterial infections are caused by pathogens that reside in biofilms, we sought to investigate how biofilms influence the evolution of antibiotic resistance. We hypothesize that the inherent spatial structure of biofilms facilitates the accumulation and persistence of spontaneously evolved antibiotic-resistant mutants. To test this, we tracked the frequency of mutants resistant to kanamycin and rifampicin in biofilm populations of Escherichia coli before, during, and after an antibiotic treatment regimen. Our results show that biofilms accumulate resistant mutants even in the absence of antibiotics. This resistance was found to be heritable and thus unlike the phenotypic plasticity of so-called "persister cells" that have been shown to occur in biofilms. Upon exposure to an antibiotic, resistant mutants swept to high frequency. Following the conclusion of treatment, these resistant mutants remained at unexpectedly high frequencies in the biofilms for over 45 days. In contrast, when samples from kanamycin-treated biofilms were used to found well-mixed liquid cultures and propagated by serial transfer, the frequency of resistant cells dramatically decreased as they were outcompeted by sensitive clones. These observations suggest that the emergence of antibiotic resistance through spontaneous mutations in spatially structured biofilms may significantly contribute to the emergence and persistence of mutants that are resistant to antibiotics used to treat bacterial infections.
Collapse
Affiliation(s)
- Michael T. France
- Institute for Bioinformatics and Evolutionary StudiesUniversity of IdahoMoscowIdaho
- Present address:
Institute for Genome Sciences, School of MedicineUniversity of MarylandBaltimoreMaryland
| | - Ana Cornea
- Department of Biological SciencesUniversity of IdahoMoscowIdaho
- Present address:
School of MedicineUniversity of WashingtonSeattleWashington
| | - Hanna Kehlet‐Delgado
- Department of Biological SciencesUniversity of IdahoMoscowIdaho
- Present address:
Department of MicrobiologyOregon State UniversityCorvallisOregon
| | - Larry J. Forney
- Institute for Bioinformatics and Evolutionary StudiesUniversity of IdahoMoscowIdaho
- Department of Biological SciencesUniversity of IdahoMoscowIdaho
| |
Collapse
|
16
|
López-Camacho E, Paño-Pardo JR, Sotillo A, Elías-López C, Martínez-Martínez L, Gómez-Gil R, Mingorance J. Meropenem heteroresistance in clinical isolates of OXA-48–producing Klebsiella pneumoniae. Diagn Microbiol Infect Dis 2019; 93:162-166. [DOI: 10.1016/j.diagmicrobio.2018.09.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 08/02/2018] [Accepted: 09/14/2018] [Indexed: 10/28/2022]
|
17
|
Spencer MD, Winglee K, Passaretti C, Earl AM, Manson AL, Mulder HP, Sautter RL, Fodor AA. Whole Genome Sequencing detects Inter-Facility Transmission of Carbapenem-resistant Klebsiella pneumoniae. J Infect 2018; 78:187-199. [PMID: 30503842 PMCID: PMC6408229 DOI: 10.1016/j.jinf.2018.11.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/03/2018] [Accepted: 11/19/2018] [Indexed: 12/22/2022]
Abstract
OBJECTIVES To identify transmission patterns of Carbapenem-resistant Klebsiella pneumoniae infection during an outbreak at a large, tertiary care hospital and to detect whether the outbreak organisms spread to other facilities in the integrated healthcare network. METHODS We analyzed 71 K. pneumoniae whole genome sequences collected from clinical specimens before, during and after the outbreak and reviewed corresponding patient medical records. Sequence and patient data were used to model probable transmissions and assess factors associated with the outbreak. RESULTS We identified close genetic relationships among carbapenem-resistant K. pneumoniae isolates sampled during the study period. Transmission tree analysis combined with patient records uncovered extended periods of silent colonization in many study patients and transmission routes that were likely the result of asymptomatic patients transitioning between facilities. CONCLUSIONS Detecting how and where Carbapenem-resistant K. pneumoniae infections spread is challenging in an environment of rising prevalence, asymptomatic carriage and mobility of patients. Whole genome sequencing improved the precision of investigating inter-facility transmissions. Our results emphasize that containment of Carbapenem-resistant K. pneumoniae infections requires coordinated efforts between healthcare networks and settings of care that acknowledge and mitigate transmission risk conferred by undetected carriage and by patient transfers between facilities.
Collapse
Affiliation(s)
- Melanie D Spencer
- Center for Outcomes Research and Evaluation, Atrium Health, Research Office Building, 1540 Garden Terrace, Charlotte, NC 28203, USA.
| | - Kathryn Winglee
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, 9331 Robert D. Snyder Road, Charlotte NC 28223, USA.
| | - Catherine Passaretti
- Departments of Internal Medicine and Infectious Disease, Atrium Health, 1616 Scott Avenue, Charlotte, NC 28203, USA.
| | - Ashlee M Earl
- Broad Institute of Harvard and Massachusetts Institute of Technology, 415 Main Street, Cambridge, MA 02142, USA.
| | - Abigail L Manson
- Broad Institute of Harvard and Massachusetts Institute of Technology, 415 Main Street, Cambridge, MA 02142, USA.
| | - Holly P Mulder
- Center for Outcomes Research and Evaluation, Atrium Health, Research Office Building, 1540 Garden Terrace, Charlotte, NC 28203, USA.
| | - Robert L Sautter
- Carolinas Pathology Group, P.O. Box 30637, Charlotte, NC 28230, USA.
| | - Anthony A Fodor
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, 9331 Robert D. Snyder Road, Charlotte NC 28223, USA.
| |
Collapse
|
18
|
Nicolas-Chanoine MH, Mayer N, Guyot K, Dumont E, Pagès JM. Interplay Between Membrane Permeability and Enzymatic Barrier Leads to Antibiotic-Dependent Resistance in Klebsiella Pneumoniae. Front Microbiol 2018; 9:1422. [PMID: 30008709 PMCID: PMC6034560 DOI: 10.3389/fmicb.2018.01422] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 06/11/2018] [Indexed: 12/12/2022] Open
Abstract
The interplay between membrane permeability alterations and the enzymatic barrier contributes to Klebsiella pneumoniae multidrug resistance. We assessed the specific effect of the efflux levels of the main efflux pumps (AcrAB and OqxAB), alone and associated with the loss of the main porins (OmpK35 and OMPK36), on the activity of various antibiotics by constructing a set of K. pneumoniae isogenic strains, including strains with plasmid-mediated β-lactamases (DHA-1, CTX-M-15, and OXA-48). The two pumps contributed to intrinsic chloramphenicol resistance and AcrAB to that of nalidixic acid and cefoxitin, whereas they had no impact on the activity of the other 11 antibiotics tested. We confirmed the expulsion of these three antibiotics by the two overproduced pumps and that of tigecycline by overproduced AcrAB, and showed that overproduced AcrAB also expelled ertapenem, piperacillin, ceftolozane, and ceftazidime. The sole loss of porins did not significantly affect the activity of the tested antibiotics, except ertapenem. The effect of efflux increases and porin loss on β-lactam activity was the highest in plasmid-mediated β-lactamase-producing strains. Thus, DHA-1-producing strains became non-susceptible (NS) to (i) ertapenem when there was an increase in efflux or porin loss, (ii) imipenem and ceftazidime+avibactam when the two mechanisms were associated, and (iii) temocillin when AcrAB was overproduced. The CTX-M-15-producing strains became NS to (i) ertapenem when there was no porin, (ii) ceftolozane+tazobactam when there was either overproduced OqxAB or porin loss, and (iii) temocillin when AcrAB was overproduced. OXA-48-producing strains known to be NS to temocillin were also NS to ceftolozane and they became NS to imipenem when the two pumps were overproduced or there was porin loss. Overall, this study shows that the balance between influx and efflux differentially modulates the activity of the tested antibiotics, an important point for evaluating the activity of future antibiotics or new combinations.
Collapse
Affiliation(s)
- Marie-Helene Nicolas-Chanoine
- Service de Microbiologie, Hôpital Beaujon, AP-HP, Clichy, France.,Faculté de Médecine D. Diderot, Paris, France.,Institut National de la Santé et de la Recherche Médicale UMR 1137, Université Paris 7, Paris, France
| | - Noémie Mayer
- Service de Microbiologie, Hôpital Beaujon, AP-HP, Clichy, France
| | - Kathleen Guyot
- Service de Microbiologie, Hôpital Beaujon, AP-HP, Clichy, France
| | | | | |
Collapse
|
19
|
Becker L, Fuchs S, Pfeifer Y, Semmler T, Eckmanns T, Korr G, Sissolak D, Friedrichs M, Zill E, Tung ML, Dohle C, Kaase M, Gatermann S, Rüssmann H, Steglich M, Haller S, Werner G. Whole Genome Sequence Analysis of CTX-M-15 Producing Klebsiella Isolates Allowed Dissecting a Polyclonal Outbreak Scenario. Front Microbiol 2018. [PMID: 29527200 PMCID: PMC5829066 DOI: 10.3389/fmicb.2018.00322] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Extended-spectrum β-lactamase (ESBL) producing Klebsiella pneumoniae pose an important threat of infection with increased morbidity and mortality, especially for immunocompromised patients. Here, we use the rise of multidrug-resistant K. pneumoniae in a German neurorehabilitation center from April 2015 to April 2016 to dissect the benefit of whole genome sequencing (WGS) for outbreak analyses. In total, 53 isolates were obtained from 52 patients and examined using WGS. Two independent analysis strategies (reference-based and -free) revealed the same distinct clusters of two CTX-M-15 producing K. pneumoniae clones (ST15, n = 31; ST405, n = 7) and one CTX-M-15 producing Klebsiella quasipneumoniae strain (ST414, n = 8). Additionally, we determined sequence variations associated with antimicrobial resistance phenotypes in single isolates expressing carbapenem and colistin resistance, respectively. For rapid detection of the major K. pneumoniae outbreak clone (ST15), a selective triplex PCR was deduced from WGS data of the major outbreak strain and K. pneumoniae genome data deposited in central databases. Moreover, we introduce two novel open-source applications supporting reference genome selection (refRank; https://gitlab.com/s.fuchs/refRank) and alignment-based SNP-filtering (SNPfilter; https://gitlab.com/s.fuchs/snpfilter) in NGS analyses.
Collapse
Affiliation(s)
- Laura Becker
- Department of Infectious Diseases, Robert Koch Institute, Berlin, Germany
| | - Stephan Fuchs
- Department of Infectious Diseases, Robert Koch Institute, Berlin, Germany
| | - Yvonne Pfeifer
- Department of Infectious Diseases, Robert Koch Institute, Berlin, Germany
| | - Torsten Semmler
- Department of Infectious Diseases, Robert Koch Institute, Berlin, Germany
| | - Tim Eckmanns
- Department of Infectious Diseases, Robert Koch Institute, Berlin, Germany
| | - Gerit Korr
- Department of Infectious Diseases, Robert Koch Institute, Berlin, Germany.,Postgraduate Training for Applied Epidemiology, Robert Koch Institute, Affiliated to the European Programme for Intervention Epidemiology Training, European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden
| | - Dagmar Sissolak
- Department of Infection Control, Medical Disaster Control and Environmental Health Control, Department of Public Health, Berlin, Germany
| | | | - Edith Zill
- Medical Care Centre Labor 28 GmbH, Berlin, Germany
| | | | | | - Martin Kaase
- National Reference Centre for Multidrug-Resistant Gram-Negative Bacteria, Department for Medical Microbiology, Ruhr-University Bochum, Berlin, Germany
| | - Sören Gatermann
- National Reference Centre for Multidrug-Resistant Gram-Negative Bacteria, Department for Medical Microbiology, Ruhr-University Bochum, Berlin, Germany
| | - Holger Rüssmann
- Immunology and Laboratory Medicine, Institute for Microbiology, HELIOS Klinikum Emil von Behring, Berlin, Germany
| | - Matthias Steglich
- Leibniz Institute DSMZ, German Collection of Microorganisms and Cell Culture, Braunschweig, Germany
| | - Sebastian Haller
- Department of Infectious Diseases, Robert Koch Institute, Berlin, Germany
| | - Guido Werner
- Department of Infectious Diseases, Robert Koch Institute, Berlin, Germany
| |
Collapse
|
20
|
Genomic Insights into Colistin-Resistant Klebsiella pneumoniae from a Tunisian Teaching Hospital. Antimicrob Agents Chemother 2018; 62:AAC.01601-17. [PMID: 29229634 DOI: 10.1128/aac.01601-17] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 11/27/2017] [Indexed: 11/20/2022] Open
Abstract
The emergence of colistin-resistant Klebsiella pneumoniae (CoRKp) is a public health concern, since this antibiotic has become the last line of treatment for infections caused by multidrug-resistant (MDR) Gram negatives. In this study, we have investigated the molecular basis of colistin resistance in 13 MDR K. pneumoniae strains isolated from 12 patients in a teaching hospital in Sousse, Tunisia. Whole-genome sequencing (WGS) was used to decipher the molecular mechanism of colistin resistance and to identify the resistome of these CoRKp isolates. It revealed a genome of ca. 5.5 Mbp in size with a G+C content of 57%, corresponding to that commonly observed for K. pneumoniae These isolates belonged to the 5 different sequence types (ST11, ST15, ST101, ST147, and ST392), and their resistome was composed of acquired β-lactamases, including extended-spectrum beta-lactamase and carbapenemase genes (blaCTX-M-15, blaOXA-204, blaOXA-48, and blaNDM-1 genes), aminoglycoside resistance genes [aac(6')Ib-cr, aph(3″)-Ib, aph(6)-Id, and aac(3)-IIa], and fosfomycin (fosA), fluoroquinolone (qnr-like), chloramphenicol, trimethoprim, and tetracycline resistance genes. All of the isolates were identified as having a mutated mgrB gene. Mapping reads with reference sequences of the most common genes involved in colistin resistance revealed several modifications in mgrB, pmr, and pho operons (deletions, insertions, and substitutions) likely affecting the function of these proteins. It is worth noting that among the 12 patients, 10 were treated with colistin before the isolation of CoRKp No plasmid encoding mcr-1 to mcr-5 genes was found in these isolates. This study corresponds to the first molecular characterization of a collection of CoRKp strains in Tunisia and highlights that the small-transmembrane protein MgrB is a main mechanism for colistin resistance in K. pneumoniae.
Collapse
|
21
|
Polymyxins: Antibacterial Activity, Susceptibility Testing, and Resistance Mechanisms Encoded by Plasmids or Chromosomes. Clin Microbiol Rev 2017; 30:557-596. [PMID: 28275006 DOI: 10.1128/cmr.00064-16] [Citation(s) in RCA: 886] [Impact Index Per Article: 126.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Polymyxins are well-established antibiotics that have recently regained significant interest as a consequence of the increasing incidence of infections due to multidrug-resistant Gram-negative bacteria. Colistin and polymyxin B are being seriously reconsidered as last-resort antibiotics in many areas where multidrug resistance is observed in clinical medicine. In parallel, the heavy use of polymyxins in veterinary medicine is currently being reconsidered due to increased reports of polymyxin-resistant bacteria. Susceptibility testing is challenging with polymyxins, and currently available techniques are presented here. Genotypic and phenotypic methods that provide relevant information for diagnostic laboratories are presented. This review also presents recent works in relation to recently identified mechanisms of polymyxin resistance, including chromosomally encoded resistance traits as well as the recently identified plasmid-encoded polymyxin resistance determinant MCR-1. Epidemiological features summarizing the current knowledge in that field are presented.
Collapse
|
22
|
Kidd TJ, Mills G, Sá-Pessoa J, Dumigan A, Frank CG, Insua JL, Ingram R, Hobley L, Bengoechea JA. A Klebsiella pneumoniae antibiotic resistance mechanism that subdues host defences and promotes virulence. EMBO Mol Med 2017; 9:430-447. [PMID: 28202493 PMCID: PMC5376759 DOI: 10.15252/emmm.201607336] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Klebsiella pneumoniae is an important cause of multidrug‐resistant infections worldwide. Recent studies highlight the emergence of multidrug‐resistant K. pneumoniae strains which show resistance to colistin, a last‐line antibiotic, arising from mutational inactivation of the mgrB regulatory gene. However, the precise molecular resistance mechanisms of mgrB‐associated colistin resistance and its impact on virulence remain unclear. Here, we constructed an mgrB gene K. pneumoniae mutant and performed characterisation of its lipid A structure, polymyxin and antimicrobial peptide resistance, virulence and inflammatory responses upon infection. Our data reveal that mgrB mutation induces PhoPQ‐governed lipid A remodelling which confers not only resistance to polymyxins, but also enhances K. pneumoniae virulence by decreasing antimicrobial peptide susceptibility and attenuating early host defence response activation. Overall, our findings have important implications for patient management and antimicrobial stewardship, while also stressing antibiotic resistance development is not inexorably linked with subdued bacterial fitness and virulence.
Collapse
Affiliation(s)
- Timothy J Kidd
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, UK.,School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Qld, Australia.,Child Health Research Centre, The University of Queensland, Brisbane, Qld, Australia
| | - Grant Mills
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - Joana Sá-Pessoa
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - Amy Dumigan
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - Christian G Frank
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - José L Insua
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - Rebecca Ingram
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - Laura Hobley
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - José A Bengoechea
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, UK
| |
Collapse
|
23
|
Co-resistance to colistin and tigecycline by disrupting mgrB and ramR with IS insertions in a canine Klebsiella pneumoniae ST37 isolate producing SHV-12, DHA-1 and FosA3. Int J Antimicrob Agents 2017; 50:697-698. [PMID: 28943368 DOI: 10.1016/j.ijantimicag.2017.09.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 09/13/2017] [Accepted: 09/14/2017] [Indexed: 11/23/2022]
|
24
|
Deciphering Heteroresistance to Colistin in a Klebsiella pneumoniae Isolate from Marseille, France. Antimicrob Agents Chemother 2017; 61:AAC.00356-17. [PMID: 28416544 DOI: 10.1128/aac.00356-17] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 04/06/2017] [Indexed: 11/20/2022] Open
Abstract
Here, we report the description of a colistin-heteroresistant Klebsiella pneumoniae isolate fortuitously isolated from the stool sample of a patient with suspicion of tuberculosis in a public hospital of Marseille, France. In the colistin-resistant subpopulation, a mutation in the mgrB gene leading to a premature stop codon was found, and the hypermucoviscous phenotype was lost. Susceptibility to other antibiotics remained unchanged. To our knowledge, this is the first identification of such a colistin-heteroresistant Klebsiella pneumoniae isolate in France.
Collapse
|
25
|
Molecular Epidemiology of Colistin-Resistant, Carbapenemase-Producing Klebsiella pneumoniae in Serbia from 2013 to 2016. Antimicrob Agents Chemother 2017; 61:AAC.02550-16. [PMID: 28242665 DOI: 10.1128/aac.02550-16] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 02/13/2017] [Indexed: 11/20/2022] Open
Abstract
Twenty-seven colistin-resistant, carbapenemase-producing Klebsiella pneumoniae isolates were identified from hospitals in Serbia. All isolates were blaCTX-M-15 positive; ST101, ST888, ST437, ST336, and ST307 were blaOXA-48 positive; and ST340 was blaNDM-1 positive. ST307 had an insertion, and ST336 had a premature stop codon in the mgrB gene. Amino acid substitutions were detected in PmrAB of isolates ST101, ST888, ST336, and ST307. The mcr-1 and mcr-2 were not detected. An increase in phoP, phoQ, and pmrK gene transcription was detected for all sequence types.
Collapse
|
26
|
Zavascki AP, Klee BO, Bulitta JB. Aminoglycosides against carbapenem-resistant Enterobacteriaceae in the critically ill: the pitfalls of aminoglycoside susceptibility. Expert Rev Anti Infect Ther 2017; 15:519-526. [PMID: 28375030 DOI: 10.1080/14787210.2017.1316193] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
INTRODUCTION The emergence of carbapenem-resistant Enterobacteriaceae (CRE) has brought aminoglycosides to the frontline since an aminoglycoside may be the only antimicrobial to which CRE isolates show in vitro susceptibility. The appropriateness of aminoglycoside-based therapies for severe infections by CRE is discussed considering the current breakpoints and recent pharmacokinetic (PK) studies in critically ill patients. Areas covered: Many aminoglycoside-susceptible CRE isolates present minimal inhibitory concentrations (MICs) at or slightly below the breakpoint of amikacin or gentamicin. However, recent PK studies with these aminoglycosides in critically ill have invariably shown that the PK/pharmacodynamic (PD) target is very unlikely attained even when high doses are administered, if the MICs are near the breakpoint. Expert commentary: While new antimicrobials are not widely available, the authors forecast an increasing use of aminoglycosides as backbone antibiotics against CRE isolates. However, the altered PK of aminoglycosides in critically ill patients severely impairs their predicted efficacy in these patients. Aminoglycoside breakpoints may hide 'aminoglycoside-susceptible' CRE isolates for that aminoglycosides will unlikely be effective if used in monotherapy. Therefore, these breakpoints may need to be revised due to the increasing use of aminoglycosides as backbone antibiotics to treat severe infections by CRE isolates in critically ill patients.
Collapse
Affiliation(s)
- Alexandre P Zavascki
- a Infectious Diseases Service , Hospital de Clinicas de Porto Alegre , Porto Alegre , Brazil.,b Department of Internal Medicine, Medical School , Universidade Federal do Rio Grande do Sul , Porto Alegre , Brazil
| | - Brandon O Klee
- c Center for Pharmacometrics and Systems Pharmacology, Department of Pharmaceutics , College of Pharmacy, University of Florida , Orlando , FL , USA
| | - Jürgen B Bulitta
- c Center for Pharmacometrics and Systems Pharmacology, Department of Pharmaceutics , College of Pharmacy, University of Florida , Orlando , FL , USA
| |
Collapse
|
27
|
Jeannot K, Bolard A, Plésiat P. Resistance to polymyxins in Gram-negative organisms. Int J Antimicrob Agents 2017; 49:526-535. [PMID: 28163137 DOI: 10.1016/j.ijantimicag.2016.11.029] [Citation(s) in RCA: 245] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 11/10/2016] [Accepted: 11/25/2016] [Indexed: 12/30/2022]
Abstract
Polymyxins have recently been re-introduced into the therapeutic arsenal to combat infections caused by multidrug-resistant Gram-negative bacteria. However, the emergence of strains resistant to these last-resort drugs is becoming a critical issue in a growing number of countries. Both intrinsic and transferable mechanisms of polymyxin resistance have been characterised. These mechanisms as well as the epidemiological data regarding four relevant bacterial pathogens (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa) are considered in this review. A special focus is made on plasmid-mediated resistance and the spread of mcr genes.
Collapse
Affiliation(s)
- Katy Jeannot
- Laboratoire de bactériologie, Centre national de référence (CNR) de la résistance aux antibiotiques, Centre hospitalier universitaire (CHRU) de Besançon, boulevard Fleming, 25000 Besançon, France.
| | - Arnaud Bolard
- Laboratoire de bactériologie, Centre national de référence (CNR) de la résistance aux antibiotiques, Centre hospitalier universitaire (CHRU) de Besançon, boulevard Fleming, 25000 Besançon, France
| | - Patrick Plésiat
- Laboratoire de bactériologie, Centre national de référence (CNR) de la résistance aux antibiotiques, Centre hospitalier universitaire (CHRU) de Besançon, boulevard Fleming, 25000 Besançon, France
| |
Collapse
|
28
|
A Prolonged Outbreak of KPC-3-Producing Enterobacter cloacae and Klebsiella pneumoniae Driven by Multiple Mechanisms of Resistance Transmission at a Large Academic Burn Center. Antimicrob Agents Chemother 2017; 61:AAC.01516-16. [PMID: 27919898 DOI: 10.1128/aac.01516-16] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 11/25/2016] [Indexed: 12/20/2022] Open
Abstract
Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacter cloacae has been recently recognized in the United States. Whole-genome sequencing (WGS) has become a useful tool for analysis of outbreaks and for determining transmission networks of multidrug-resistant organisms in health care settings, including carbapenem-resistant Enterobacteriaceae (CRE). We experienced a prolonged outbreak of CRE E. cloacae and K. pneumoniae over a 3-year period at a large academic burn center despite rigorous infection control measures. To understand the molecular mechanisms that sustained this outbreak, we investigated the CRE outbreak isolates by using WGS. Twenty-two clinical isolates of CRE, including E. cloacae (n = 15) and K. pneumoniae (n = 7), were sequenced and analyzed genetically. WGS revealed that this outbreak, which seemed epidemiologically unlinked, was in fact genetically linked over a prolonged period. Multiple mechanisms were found to account for the ongoing outbreak of KPC-3-producing E. cloacae and K. pneumoniae This outbreak was primarily maintained by a clonal expansion of E. cloacae sequence type 114 (ST114) with distribution of multiple resistance determinants. Plasmid and transposon analyses suggested that the majority of blaKPC-3 was transmitted via an identical Tn4401b element on part of a common plasmid. WGS analysis demonstrated complex transmission dynamics within the burn center at levels of the strain and/or plasmid in association with a transposon, highlighting the versatility of KPC-producing Enterobacteriaceae in their ability to utilize multiple modes to resistance gene propagation.
Collapse
|
29
|
Does Antibiotic Resistance Evolve in Hospitals? Bull Math Biol 2016; 79:191-208. [PMID: 27924410 DOI: 10.1007/s11538-016-0232-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 11/02/2016] [Indexed: 10/20/2022]
Abstract
Nosocomial outbreaks of bacteria are well documented. Based on these incidents, and the heavy usage of antibiotics in hospitals, it has been assumed that antibiotic resistance evolves in hospital environments. To test this assumption, we studied resistance phenotypes of bacteria collected from patient isolates at a community hospital over a 2.5-year period. A graphical model analysis shows no association between resistance and patient information other than time of arrival. This allows us to focus on time-course data. We introduce a hospital transmission model, based on negative binomial delay. Our main contribution is a statistical hypothesis test called the Nosocomial Evolution of Resistance Detector (NERD). It calculates the significance of resistance trends occurring in a hospital. It can inform hospital staff about the effects of various practices and interventions, can help detect clonal outbreaks, and is available as an R package. We applied the NERD method to each of the 16 antibiotics in the study via 16 hypothesis tests. For 13 of the antibiotics, we found that the hospital environment had no significant effect on the evolution of resistance; the hospital is merely a piece of the larger picture. The p-values obtained for the other three antibiotics (cefepime, ceftazidime, and gentamicin) indicate that particular care should be taken in hospital practices with these antibiotics. One of the three, ceftazidime, was significant after accounting for multiple hypotheses, indicating a trend of decreased resistance for this drug.
Collapse
|
30
|
Trimble MJ, Mlynárčik P, Kolář M, Hancock REW. Polymyxin: Alternative Mechanisms of Action and Resistance. Cold Spring Harb Perspect Med 2016; 6:cshperspect.a025288. [PMID: 27503996 DOI: 10.1101/cshperspect.a025288] [Citation(s) in RCA: 225] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Antibiotic resistance among pathogenic bacteria is an ever-increasing issue worldwide. Unfortunately, very little has been achieved in the pharmaceutical industry to combat this problem. This has led researchers and the medical field to revisit past drugs that were deemed too toxic for clinical use. In particular, the cyclic cationic peptides polymyxin B and colistin, which are specific for Gram-negative bacteria, have been used as "last resort" antimicrobials. Before the 1980s, these drugs were known for their renal and neural toxicities; however, new clinical practices and possibly improved manufacturing have made them safer to use. Previously suggested to primarily attack the membranes of Gram-negative bacteria and to not easily select for resistant mutants, recent research exploring resistance and mechanisms of action has provided new perspectives. This review focuses primarily on the proposed alternative mechanisms of action, known resistance mechanisms, and how these support the alternative mechanisms of action.
Collapse
Affiliation(s)
- Michael J Trimble
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Patrik Mlynárčik
- Department of Microbiology, Faculty of Medicine and Dentistry, Palacký University, 771 47 Olomouc, Czech Republic
| | - Milan Kolář
- Department of Microbiology, Faculty of Medicine and Dentistry, Palacký University, 771 47 Olomouc, Czech Republic
| | - Robert E W Hancock
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| |
Collapse
|
31
|
Baron S, Hadjadj L, Rolain JM, Olaitan AO. Molecular mechanisms of polymyxin resistance: knowns and unknowns. Int J Antimicrob Agents 2016; 48:583-591. [PMID: 27524102 DOI: 10.1016/j.ijantimicag.2016.06.023] [Citation(s) in RCA: 277] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 06/14/2016] [Accepted: 06/23/2016] [Indexed: 12/19/2022]
Abstract
Colistin, also referred to as polymyxin E, is an effective antibiotic against most multidrug-resistant Gram-negative bacteria and is currently used as a last-line drug for treating severe bacterial infections. Colistin resistance has increased gradually for the last few years, and knowledge of its multifaceted mechanisms is expanding. This includes the newly discovered plasmid-mediated colistin resistance gene mcr-1, which has been detected in over 20 countries within 3 months of its first report. We previously reported all of the known mechanisms of polymyxin resistance in our first review in 2014, but an update seems necessary in 2016, considering the significant recent discoveries that have been made in this domain. This review provides an update about what is already known, what is new, and some unresolved questions with respect to colistin resistance.
Collapse
Affiliation(s)
- Sophie Baron
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), CNRS-IRD UMR 6236, Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille Université, Marseille, France
| | - Linda Hadjadj
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), CNRS-IRD UMR 6236, Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille Université, Marseille, France
| | - Jean-Marc Rolain
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), CNRS-IRD UMR 6236, Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille Université, Marseille, France.
| | - Abiola Olumuyiwa Olaitan
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), CNRS-IRD UMR 6236, Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille Université, Marseille, France.
| |
Collapse
|
32
|
McGann P, Bunin JL, Snesrud E, Singh S, Maybank R, Ong AC, Kwak YI, Seronello S, Clifford RJ, Hinkle M, Yamada S, Barnhill J, Lesho E. Real time application of whole genome sequencing for outbreak investigation - What is an achievable turnaround time? Diagn Microbiol Infect Dis 2016; 85:277-282. [PMID: 27185645 DOI: 10.1016/j.diagmicrobio.2016.04.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 03/30/2016] [Accepted: 04/27/2016] [Indexed: 12/20/2022]
Abstract
Whole genome sequencing (WGS) is increasingly employed in clinical settings, though few assessments of turnaround times (TAT) have been performed in real-time. In this study, WGS was used to investigate an unfolding outbreak of vancomycin resistant Enterococcus faecium (VRE) among 3 patients in the ICU of a tertiary care hospital. Including overnight culturing, a TAT of just 48.5 h for a comprehensive report was achievable using an Illumina Miseq benchtop sequencer. WGS revealed that isolates from patient 2 and 3 differed from that of patient 1 by a single nucleotide polymorphism (SNP), indicating nosocomial transmission. However, the unparalleled resolution provided by WGS suggested that nosocomial transmission involved two separate events from patient 1 to patient 2 and 3, and not a linear transmission suspected by the time line. Rapid TAT's are achievable using WGS in the clinical setting and can provide an unprecedented level of resolution for outbreak investigations.
Collapse
Affiliation(s)
- Patrick McGann
- Multidrug-resistant Organism Repository and Surveillance Network, Walter Reed Army Institute of Research, Silver Spring, MD, USA.
| | - Jessica L Bunin
- Department of Critical Care, Tripler Army Medical Center, Honolulu, HI, USA
| | - Erik Snesrud
- Multidrug-resistant Organism Repository and Surveillance Network, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Seema Singh
- Department of Pathology, Tripler Army Medical Center, Honolulu, HI, USA
| | - Rosslyn Maybank
- Multidrug-resistant Organism Repository and Surveillance Network, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Ana C Ong
- Multidrug-resistant Organism Repository and Surveillance Network, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Yoon I Kwak
- Multidrug-resistant Organism Repository and Surveillance Network, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Scott Seronello
- Department of Pathology, Tripler Army Medical Center, Honolulu, HI, USA
| | - Robert J Clifford
- Multidrug-resistant Organism Repository and Surveillance Network, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Mary Hinkle
- Multidrug-resistant Organism Repository and Surveillance Network, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Stephen Yamada
- Infectious Diseases Service, Tripler Army Medical Center, Honolulu, HI, USA
| | - Jason Barnhill
- Department of Pathology, Tripler Army Medical Center, Honolulu, HI, USA
| | - Emil Lesho
- Multidrug-resistant Organism Repository and Surveillance Network, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| |
Collapse
|
33
|
In Vitro Susceptibility to Ceftazidime-Avibactam of Carbapenem-Nonsusceptible Enterobacteriaceae Isolates Collected during the INFORM Global Surveillance Study (2012 to 2014). Antimicrob Agents Chemother 2016; 60:3163-9. [PMID: 26926648 DOI: 10.1128/aac.03042-15] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Accepted: 02/18/2016] [Indexed: 12/26/2022] Open
Abstract
The activity of ceftazidime-avibactam was assessed against 961 isolates of meropenem-nonsusceptible Enterobacteriaceae Most meropenem-nonsusceptible metallo-β-lactamase (MBL)-negative isolates (97.7%) were susceptible to ceftazidime-avibactam. Isolates that carried KPC or OXA-48-like β-lactamases, both alone and in combination with extended-spectrum β-lactamases (ESBLs) and/or AmpC β-lactamases, were 98.7% and 98.5% susceptible to ceftazidime-avibactam, respectively. Meropenem-nonsusceptible, carbapenemase-negative isolates demonstrated 94.7% susceptibility to ceftazidime-avibactam. Ceftazidime-avibactam activity was compromised only in isolates for which carbapenem resistance was mediated through metallo-β-lactamases.
Collapse
|
34
|
Bootsma HJ, Schouls LM. Next-generation sequencing of carbapenem-resistant Gram-negative microorganisms: a key tool for surveillance and infection control. Future Microbiol 2016; 10:299-302. [PMID: 25812450 DOI: 10.2217/fmb.14.134] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Hester J Bootsma
- Centre for Infectious Diseases Research, Diagnostics & Screening (IDS), Centre for Infectious Diseases Control (CIb), National Institute of Public Health & the Environment (RIVM), Bilthoven, The Netherlands
| | | |
Collapse
|
35
|
Guo Q, Spychala CN, McElheny CL, Doi Y. Comparative analysis of an IncR plasmid carrying armA, blaDHA-1 and qnrB4 from Klebsiella pneumoniae ST37 isolates. J Antimicrob Chemother 2016; 71:882-6. [PMID: 26747096 DOI: 10.1093/jac/dkv444] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Accepted: 11/19/2015] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES The objective of this study was to conduct a comparative analysis with reported IncR plasmids of a Klebsiella pneumoniae IncR plasmid carrying an MDR region. METHODS MDR K. pneumoniae isolates were serially identified from two inpatients at a hospital in the USA in 2014. MDR plasmid pYDC676 was fully sequenced, annotated and compared with related plasmids. Antimicrobial susceptibility testing, PFGE and MLST were also conducted. RESULTS The K. pneumoniae isolates were identical by PFGE, belonged to ST37 and harboured an identical ∼50 kb IncR plasmid (pYDC676). pYDC676 possessed the backbone and multi-IS loci closely related to IncR plasmids reported from aquatic bacteria, as well as animal and human K. pneumoniae strains, and carried an MDR region consisting of armA, blaDHA-1 and qnrB4, a combination that has been reported in IncR plasmids from K. pneumoniae ST11 strains in Europe and Asia. A plasmid with the identical IncR backbone and a similar MDR region containing blaDHA-1 and qnrB4 has also been reported in ST37 strains from Europe, suggesting potential dissemination of this lineage of IncR plasmids in K. pneumoniae ST37. CONCLUSIONS K. pneumoniae ST37 strains with an MDR IncR plasmid carrying armA, blaDHA-1 and qnrB4 were identified in a hospital in the USA, where these resistance genes remain rare. The IncR backbone may play a role in the global dissemination of these resistance genes.
Collapse
Affiliation(s)
- Qinglan Guo
- Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China Key Laboratory of Clinical Pharmacology of Antibiotics, Ministry of Health, Shanghai, China
| | - Caressa Nicole Spychala
- Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Christi Lee McElheny
- Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Yohei Doi
- Division of Infectious Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| |
Collapse
|
36
|
Pagès JM, Peslier S, Keating TA, Lavigne JP, Nichols WW. Role of the Outer Membrane and Porins in Susceptibility of β-Lactamase-Producing Enterobacteriaceae to Ceftazidime-Avibactam. Antimicrob Agents Chemother 2015; 60:1349-59. [PMID: 26666933 PMCID: PMC4775948 DOI: 10.1128/aac.01585-15] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Accepted: 12/05/2015] [Indexed: 01/21/2023] Open
Abstract
This study examined the activity of the novel antimicrobial combination ceftazidime-avibactam against Enterobacteriaceae exhibiting different outer membrane permeability profiles, specifically with or without porins and with or without expression of the main efflux pump (AcrAB-TolC). The addition of the outer membrane permeabilizer polymyxin B nonapeptide increased the antibacterial activities of avibactam alone, ceftazidime alone, and ceftazidime-avibactam against the characterized clinical isolates of Escherichia coli, Enterobacter aerogenes, and Klebsiella pneumoniae. This enhancement of activities was mainly due to increased passive penetration of compounds since inhibition of efflux by the addition of phenylalanine-arginine β-naphthylamide affected the MICs minimally. OmpF (OmpK35) or OmpC (OmpK36) pores were not the major route by which avibactam crossed the outer membranes of E. coli and K. pneumoniae. In contrast, Omp35 and Omp36 allowed diffusion of avibactam across the outer membrane of E. aerogenes, although other diffusion channels for avibactam were also present in that species. It was clear that outer membrane permeability and outer membrane pore-forming proteins play a key role in the activity of ceftazidime-avibactam. Nevertheless, the MICs of ceftazidime-avibactam (with 4 mg/liter avibactam) against the ceftazidime-resistant clinical isolates of the three species of Enterobacteriaceae studied were ≤ 8 mg/liter, regardless of outer membrane permeability changes resulting from an absence of defined porin proteins or upregulation of efflux.
Collapse
Affiliation(s)
- Jean-Marie Pagès
- UMR_MD-1, Aix-Marseille Université, IRBA, Transporteurs Membranaires, Chimiorésistance et Drug Design, Marseille, France
| | - Sabine Peslier
- UMR_MD-1, Aix-Marseille Université, IRBA, Transporteurs Membranaires, Chimiorésistance et Drug Design, Marseille, France
| | - Thomas A Keating
- AstraZeneca Infection Innovative Medicines, Waltham, Massachusetts, USA
| | - Jean-Philippe Lavigne
- Institut National de la Santé et de la Recherche Médicale, U1047, Université Montpellier 1, Nîmes, France Department of Microbiology, University Hospital Caremeau, Nîmes, France
| | - Wright W Nichols
- AstraZeneca Infection Innovative Medicines, Waltham, Massachusetts, USA
| |
Collapse
|
37
|
Zowawi HM, Forde BM, Alfaresi M, Alzarouni A, Farahat Y, Chong TM, Yin WF, Chan KG, Li J, Schembri MA, Beatson SA, Paterson DL. Stepwise evolution of pandrug-resistance in Klebsiella pneumoniae. Sci Rep 2015; 5:15082. [PMID: 26478520 PMCID: PMC4609946 DOI: 10.1038/srep15082] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 09/01/2015] [Indexed: 01/21/2023] Open
Abstract
Carbapenem resistant Enterobacteriaceae (CRE) pose an urgent risk to global human health. CRE that are non-susceptible to all commercially available antibiotics threaten to return us to the pre-antibiotic era. Using Single Molecule Real Time (SMRT) sequencing we determined the complete genome of a pandrug-resistant Klebsiella pneumoniae isolate, representing the first complete genome sequence of CRE resistant to all commercially available antibiotics. The precise location of acquired antibiotic resistance elements, including mobile elements carrying genes for the OXA-181 carbapenemase, were defined. Intriguingly, we identified three chromosomal copies of an ISEcp1-bla(OXA-181) mobile element, one of which has disrupted the mgrB regulatory gene, accounting for resistance to colistin. Our findings provide the first description of pandrug-resistant CRE at the genomic level, and reveal the critical role of mobile resistance elements in accelerating the emergence of resistance to other last resort antibiotics.
Collapse
Affiliation(s)
- Hosam M Zowawi
- The University of Queensland, Centre for Clinical Research (UQCCR), Herston QLD 4029, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia.,College of Medicine, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.,World Health Organization Collaborating Centre for Infection Prevention and Control, and the Gulf Cooperation Council Center for Infection Control, Riyadh, Saudi Arabia
| | - Brian M Forde
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Mubarak Alfaresi
- Pathology and Laboratory Medicine Department at Sheikh Khalifa General Hospital, Umm Al Quwain, United Arab Emirates
| | - Abdulqadir Alzarouni
- Urology Department, Sheikh Khalifa General Hospital, Umm Al Quwain, United Arab Emirates
| | - Yasser Farahat
- Urology Department, Sheikh Khalifa General Hospital, Umm Al Quwain, United Arab Emirates
| | - Teik-Min Chong
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Wai-Fong Yin
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Kok-Gan Chan
- Division of Genetics and Molecular Biology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Jian Li
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Mark A Schembri
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Scott A Beatson
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - David L Paterson
- The University of Queensland, Centre for Clinical Research (UQCCR), Herston QLD 4029, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Australia
| |
Collapse
|
38
|
Punina NV, Makridakis NM, Remnev MA, Topunov AF. Whole-genome sequencing targets drug-resistant bacterial infections. Hum Genomics 2015; 9:19. [PMID: 26243131 PMCID: PMC4525730 DOI: 10.1186/s40246-015-0037-z] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 07/03/2015] [Indexed: 01/07/2023] Open
Abstract
During the past two decades, the technological progress of whole-genome sequencing (WGS) had changed the fields of Environmental Microbiology and Biotechnology, and, currently, is changing the underlying principles, approaches, and fundamentals of Public Health, Epidemiology, Health Economics, and national productivity. Today’s WGS technologies are able to compete with conventional techniques in cost, speed, accuracy, and resolution for day-to-day control of infectious diseases and outbreaks in clinical laboratories and in long-term epidemiological investigations. WGS gives rise to an exciting future direction for personalized Genomic Epidemiology. One of the most vital and growing public health problems is the emerging and re-emerging of multidrug-resistant (MDR) bacterial infections in the communities and healthcare settings, reinforced by a decline in antimicrobial drug discovery. In recent years, retrospective analysis provided by WGS has had a great impact on the identification and tracking of MDR microorganisms in hospitals and communities. The obtained genomic data are also important for developing novel easy-to-use diagnostic assays for clinics, as well as for antibiotic and therapeutic development at both the personal and population levels. At present, this technology has been successfully applied as an addendum to the real-time diagnostic methods currently used in clinical laboratories. However, the significance of WGS for public health may increase if: (a) unified and user-friendly bioinformatics toolsets for easy data interpretation and management are established, and (b) standards for data validation and verification are developed. Herein, we review the current and future impact of this technology on diagnosis, prevention, treatment, and control of MDR infectious bacteria in clinics and on the global scale.
Collapse
Affiliation(s)
- N V Punina
- Bach Institute of Biochemistry, Russian Academy of Science, Moscow, 119071, Russia.
| | - N M Makridakis
- Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, 70112, USA
| | - M A Remnev
- The Federal State Unitary Enterprise All-Russia Research Institute of Automatics, Moscow, 127055, Russia
| | - A F Topunov
- Bach Institute of Biochemistry, Russian Academy of Science, Moscow, 119071, Russia
| |
Collapse
|
39
|
Sublethal concentrations of carbapenems alter cell morphology and genomic expression of Klebsiella pneumoniae biofilms. Antimicrob Agents Chemother 2015; 59:1707-17. [PMID: 25583711 DOI: 10.1128/aac.04581-14] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Klebsiella pneumoniae, a Gram-negative bacterium, is normally associated with pneumonia in patients with weakened immune systems. However, it is also a prevalent nosocomial infectious agent that can be found in infected surgical sites and combat wounds. Many of these clinical strains display multidrug resistance. We have worked with a clinical strain of K. pneumoniae that was initially isolated from a wound of an injured soldier. This strain demonstrated resistance to many commonly used antibiotics but sensitivity to carbapenems. This isolate was capable of forming biofilms in vitro, contributing to its increased antibiotic resistance and impaired clearance. We were interested in determining how sublethal concentrations of carbapenem treatment specifically affect K. pneumoniae biofilms both in morphology and in genomic expression. Scanning electron microscopy showed striking morphological differences between untreated and treated biofilms, including rounding, blebbing, and dimpling of treated cells. Comparative transcriptome analysis using RNA sequencing (RNA-Seq) technology identified a large number of open reading frames (ORFs) differentially regulated in response to carbapenem treatment at 2 and 24 h. ORFs upregulated with carbapenem treatment included genes involved in resistance, as well as those coding for antiporters and autoinducers. ORFs downregulated included those coding for metal transporters, membrane biosynthesis proteins, and motility proteins. Quantitative real-time PCR validated the general trend of some of these differentially regulated ORFs. Treatment of K. pneumoniae biofilms with sublethal concentrations of carbapenems induced a wide range of phenotypic and gene expression changes. This study reveals some of the mechanisms underlying how sublethal amounts of carbapenems could affect the overall fitness and pathogenic potential of K. pneumoniae biofilm cells.
Collapse
|
40
|
Wright MS, Suzuki Y, Jones MB, Marshall SH, Rudin SD, van Duin D, Kaye K, Jacobs MR, Bonomo RA, Adams MD. Genomic and transcriptomic analyses of colistin-resistant clinical isolates of Klebsiella pneumoniae reveal multiple pathways of resistance. Antimicrob Agents Chemother 2015; 59:536-43. [PMID: 25385117 PMCID: PMC4291396 DOI: 10.1128/aac.04037-14] [Citation(s) in RCA: 147] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 11/02/2014] [Indexed: 12/28/2022] Open
Abstract
The emergence of multidrug-resistant (MDR) Klebsiella pneumoniae has resulted in a more frequent reliance on treatment using colistin. However, resistance to colistin (Col(r)) is increasingly reported from clinical settings. The genetic mechanisms that lead to Col(r) in K. pneumoniae are not fully characterized. Using a combination of genome sequencing and transcriptional profiling by RNA sequencing (RNA-Seq) analysis, distinct genetic mechanisms were found among nine Col(r) clinical isolates. Col(r) was related to mutations in three different genes in K. pneumoniae strains, with distinct impacts on gene expression. Upregulation of the pmrH operon encoding 4-amino-4-deoxy-L-arabinose (Ara4N) modification of lipid A was found in all Col(r) strains. Alteration of the mgrB gene was observed in six strains. One strain had a mutation in phoQ. Common among these seven strains was elevated expression of phoPQ and unaltered expression of pmrCAB, which is involved in phosphoethanolamine addition to lipopolysaccharide (LPS). In two strains, separate mutations were found in a previously uncharacterized histidine kinase gene that is part of a two-component regulatory system (TCRS) now designated crrAB. In these strains, expression of pmrCAB, crrAB, and an adjacent glycosyltransferase gene, but not that of phoPQ, was elevated. Complementation with the wild-type allele restored colistin susceptibility in both strains. The crrAB genes are present in most K. pneumoniae genomes, but not in Escherichia coli. Additional upregulated genes in all strains include those involved in cation transport and maintenance of membrane integrity. Because the crrAB genes are present in only some strains, Col(r) mechanisms may be dependent on the genetic background.
Collapse
Affiliation(s)
| | - Yo Suzuki
- J. Craig Venter Institute, La Jolla, California, USA
| | | | - Steven H Marshall
- Research Service, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio, USA
| | - Susan D Rudin
- Research Service, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio, USA
| | - David van Duin
- Division of Infectious Diseases, University of North Carolina, Chapel Hill, North Carolina
| | - Keith Kaye
- Detroit Medical Center, Detroit, Michigan, USA
| | - Michael R Jacobs
- Department of Pathology, Case Western Reserve University and University Hospitals Case Medical Center, Cleveland, Ohio, USA
| | - Robert A Bonomo
- Research Service, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio, USA Departments of Medicine, Pharmacology, Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Mark D Adams
- J. Craig Venter Institute, La Jolla, California, USA
| |
Collapse
|
41
|
Worldwide emergence of colistin resistance in Klebsiella pneumoniae from healthy humans and patients in Lao PDR, Thailand, Israel, Nigeria and France owing to inactivation of the PhoP/PhoQ regulator mgrB: an epidemiological and molecular study. Int J Antimicrob Agents 2014; 44:500-7. [DOI: 10.1016/j.ijantimicag.2014.07.020] [Citation(s) in RCA: 203] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 07/11/2014] [Accepted: 07/23/2014] [Indexed: 11/22/2022]
|
42
|
van Duin D, Cober E, Richter SS, Perez F, Cline M, Kaye KS, Kalayjian RC, Salata RA, Evans S, Fowler VG, Bonomo RA. Tigecycline therapy for carbapenem-resistant Klebsiella pneumoniae (CRKP) bacteriuria leads to tigecycline resistance. Clin Microbiol Infect 2014; 20:O1117-20. [PMID: 24931918 PMCID: PMC4265572 DOI: 10.1111/1469-0691.12714] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 05/26/2014] [Accepted: 06/08/2014] [Indexed: 01/08/2023]
Abstract
Carbapenem-resistant Klebsiella pneumoniae (CRKP) is an increasing global threat. Here, we describe the prevalence and impact of tigecycline use in a cohort of patients with CRKP bacteriuria nested within a multicentre, prospective study. In the 21-month study period, 260 unique patients were included. Tigecycline was given to 80 (31%) patients. The use of tigecycline during the index hospitalization was significantly associated with the subsequent development of tigecycline resistance in the same patient (OR, 6.13; 95% CI, 1.15-48.65; p 0.03). In conclusion, the use of tigecycline with CRKP bacteriuria is common, and is associated with the subsequent development of tigecycline resistance.
Collapse
Affiliation(s)
- David van Duin
- Division of Infectious Diseases, University of North Carolina, Chapel Hill, NC
| | - Eric Cober
- Department of Infectious Diseases, Cleveland Clinic, Cleveland, OH
| | | | - Federico Perez
- Research Service, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland OH
| | - Marianne Cline
- Department of Clinical Pathology, Cleveland Clinic, Cleveland, OH
| | - Keith S. Kaye
- Division of Infectious Diseases, Detroit Medical Center, Wayne State University, Detroit, MI, USA
| | | | - Robert A. Salata
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland OH
| | - Scott Evans
- Department of Biostatistics and the Center for Biostatistics in AIDS Research, Harvard School of Public Health, Boston, MA
| | - Vance G. Fowler
- Division of Infectious Diseases, Duke University Medical Center, Durham, NC
| | - Robert A. Bonomo
- Department of Clinical Pathology, Cleveland Clinic, Cleveland, OH
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland OH
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland OH
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland OH
| |
Collapse
|
43
|
Olaitan AO, Morand S, Rolain JM. Mechanisms of polymyxin resistance: acquired and intrinsic resistance in bacteria. Front Microbiol 2014; 5:643. [PMID: 25505462 PMCID: PMC4244539 DOI: 10.3389/fmicb.2014.00643] [Citation(s) in RCA: 891] [Impact Index Per Article: 89.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 11/07/2014] [Indexed: 01/06/2023] Open
Abstract
Polymyxins are polycationic antimicrobial peptides that are currently the last-resort antibiotics for the treatment of multidrug-resistant, Gram-negative bacterial infections. The reintroduction of polymyxins for antimicrobial therapy has been followed by an increase in reports of resistance among Gram-negative bacteria. Some bacteria, such as Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii, develop resistance to polymyxins in a process referred to as acquired resistance, whereas other bacteria, such as Proteus spp., Serratia spp., and Burkholderia spp., are naturally resistant to these drugs. Reports of polymyxin resistance in clinical isolates have recently increased, including acquired and intrinsically resistant pathogens. This increase is considered a serious issue, prompting concern due to the low number of currently available effective antibiotics. This review summarizes current knowledge concerning the different strategies bacteria employ to resist the activities of polymyxins. Gram-negative bacteria employ several strategies to protect themselves from polymyxin antibiotics (polymyxin B and colistin), including a variety of lipopolysaccharide (LPS) modifications, such as modifications of lipid A with phosphoethanolamine and 4-amino-4-deoxy-L-arabinose, in addition to the use of efflux pumps, the formation of capsules and overexpression of the outer membrane protein OprH, which are all effectively regulated at the molecular level. The increased understanding of these mechanisms is extremely vital and timely to facilitate studies of antimicrobial peptides and find new potential drugs targeting clinically relevant Gram-negative bacteria.
Collapse
Affiliation(s)
- Abiola O Olaitan
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes CNRS-IRD UMR 6236, Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille-Université Marseille, France
| | - Serge Morand
- Institut des Sciences de l'Evolution, CNRS-IRD-UM2, CC065, Université Montpellier 2 Montpellier, France
| | - Jean-Marc Rolain
- Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes CNRS-IRD UMR 6236, Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille-Université Marseille, France
| |
Collapse
|
44
|
High prevalence of carbapenem resistance among plasmid-mediated AmpC β-lactamase-producing Klebsiella pneumoniae during outbreaks in liver transplantation units. Int J Antimicrob Agents 2014; 45:33-40. [PMID: 25455850 DOI: 10.1016/j.ijantimicag.2014.08.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 08/21/2014] [Accepted: 08/22/2014] [Indexed: 01/17/2023]
Abstract
During a prospective surveillance using PCR for the detection of plasmid-mediated AmpC β-lactamase (pAmpC)-producing Enterobacteriaceae, outbreaks due to pAmpC-producing Klebsiella pneumoniae (pAmpC-Kp) occurred in an adult liver transplantation unit (aLTU) and a paediatric liver transplantation unit (pLTU), with carbapenem-resistant (CR) variants. Between April 2010 and March 2012, a total of 32 patients infected with pAmpC-Kp were found by prospective surveillance using PCR detection at a Japanese university hospital. Multilocus sequence typing, analysis of outer membrane proteins, and detection of carbapenemases were performed. Clinical courses of patients with bloodstream infection (BSI) were reviewed. Of 32 pAmpC-Kp isolates from each patient, 20 (18 from aLTU patients) were DHA-1-producing sequence type 11 (DHA-1-ST11), 9 were CMY-2-ST45/778 (all from pLTU patients) and the other 3 isolates had different sequence types. CR variants were isolated from 8 aLTU patients with DHA-1-ST11 and from 1 pLTU patient with CMY-2-ST45. All of the pAmpC-Kp isolates, including CR variants, were negative for carbapenemases. All of the DHA-1-ST11 and CMY-2-ST45 isolates lacked OmpK35, and seven CR variants also lacked OmpK36. BSIs due to DHA-1-ST11 isolates, including CR variants, occurred in six aLTU patients, four of whom died. The outbreaks were controlled after application of intensified infection control measures. During pAmpC-Kp outbreaks involving 27 liver transplants, CR variants with porin loss developed in nine patients, and DHA-1-ST11 K. pneumoniae caused BSIs with high mortality.
Collapse
|
45
|
Poirel L, Jayol A, Bontron S, Villegas MV, Ozdamar M, Turkoglu S, Nordmann P. The mgrB gene as a key target for acquired resistance to colistin in Klebsiella pneumoniae. J Antimicrob Chemother 2014; 70:75-80. [DOI: 10.1093/jac/dku323] [Citation(s) in RCA: 206] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
46
|
Genetic and kinetic characterization of the novel AmpC β-lactamases DHA-6 and DHA-7. Antimicrob Agents Chemother 2014; 58:6544-9. [PMID: 25136023 DOI: 10.1128/aac.03144-14] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During a Spanish surveillance study, two natural variants of DHA β-lactamases, DHA-6 and DHA-7, were found, with the replacements Ala226Thr and Phe322Ser, respectively, with respect to DHA-1. The DHA-6 and DHA-7 enzymes were isolated from Escherichia coli and Enterobacter cloacae clinical isolates, respectively. The aim of this study was to genetically, microbiologically, and biochemically characterize the DHA-6 and DHA-7 β-lactamases. The blaDHA-6 and blaDHA-7 genes were located in the I1 and HI2 incompatibility group plasmids of 87.3 and 310.4 kb, respectively. The genetic contexts of blaDHA-6 and blaDHA-7 were similar to that already described for the blaDHA-1 gene and included the qnrB4 and aadA genes. The MICs for cephalothin, aztreonam, cefotaxime, and ceftazidime were 8- to 32-fold lower for DHA-6 than for DHA-1 or DHA-7 expressed in the same isogenic E. coli TG1 strain. Interestingly, the MIC for cefoxitin was higher in the DHA-6-expressing transformant than in DHA-1 or DHA-7. Biochemical studies with pure β-lactamases revealed slightly lower catalytic efficiencies of DHA-6 against cephalothin, ceftazidime, and cefotaxime than those of DHA-1 and DHA-7. To understand this behavior, stability experiments were carried out and showed that the DHA-6 protein displayed significantly higher stability than the DHA-1 and DHA-7 enzymes. The proximity of Thr226 to the N terminus in the tertiary protein structure in DHA-6 may promote this stabilization and, consequently, may induce a slight reduction in the dynamic of this enzyme that primarily affects the hydrolysis of some of the bulkiest antibiotics.
Collapse
|
47
|
Köser CU, Ellington MJ, Peacock SJ. Whole-genome sequencing to control antimicrobial resistance. Trends Genet 2014; 30:401-7. [PMID: 25096945 PMCID: PMC4156311 DOI: 10.1016/j.tig.2014.07.003] [Citation(s) in RCA: 182] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 07/10/2014] [Accepted: 07/14/2014] [Indexed: 11/18/2022]
Abstract
Following recent improvements in sequencing technologies, whole-genome sequencing (WGS) is positioned to become an essential tool in the control of antibiotic resistance, a major threat in modern healthcare. WGS has already found numerous applications in this area, ranging from the development of novel antibiotics and diagnostic tests through to antibiotic stewardship of currently available drugs via surveillance and the elucidation of the factors that allow the emergence and persistence of resistance. Numerous proof-of-principle studies have also highlighted the value of WGS as a tool for day-to-day infection control and, for some pathogens, as a primary diagnostic tool to detect antibiotic resistance. However, appropriate data analysis platforms will need to be developed before routine WGS can be introduced on a large scale.
Collapse
Affiliation(s)
- Claudio U Köser
- Department of Medicine, University of Cambridge, Cambridge, UK.
| | - Matthew J Ellington
- Clinical Microbiology and Public Health Laboratory, Public Health England, Cambridge, UK
| | - Sharon J Peacock
- Department of Medicine, University of Cambridge, Cambridge, UK; Clinical Microbiology and Public Health Laboratory, Public Health England, Cambridge, UK; Cambridge University Hospitals National Health Service Foundation Trust, Cambridge, UK; Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| |
Collapse
|
48
|
Draft Whole-Genome Sequence of OXA-48-Producing Multidrug-Resistant Klebsiella pneumoniae KP_ST11_OXA-48. GENOME ANNOUNCEMENTS 2014; 2:2/4/e00737-14. [PMID: 25081259 PMCID: PMC4118062 DOI: 10.1128/genomea.00737-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
We present the draft genome sequence of a blood culture isolate of OXA-48-producing Klebsiella pneumoniae (sequence type 11 [ST11]) obtained in the course of a hospital outbreak in Spain. Sequence analysis showed 121 genes related to antibiotic and antiseptic resistance, including blaOXA-48, which was located in an IncL/M plasmid.
Collapse
|
49
|
MgrB inactivation is a common mechanism of colistin resistance in KPC-producing Klebsiella pneumoniae of clinical origin. Antimicrob Agents Chemother 2014; 58:5696-703. [PMID: 25022583 DOI: 10.1128/aac.03110-14] [Citation(s) in RCA: 239] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Klebsiella pneumoniae strains producing KPC-type carbapenemases (KPC-KP) are challenging multidrug-resistant pathogens due to their extensively drug-resistant phenotypes and potential for epidemic dissemination in health care settings. Colistin is a key component of the combination antimicrobial regimens used for treatment of severe KPC-KP infections. We previously reported that insertional inactivation of the mgrB gene, encoding a negative-feedback regulator of the PhoQ-PhoP signaling system, can be responsible for colistin resistance in KPC-KP, due to the resulting upregulation of the Pmr lipopolysaccharide modification system. In this work we investigated the status of the mgrB gene in a collection of 66 colistin-resistant nonreplicate clinical strains of KPC-KP isolated from different hospitals in Italy and Greece. Overall, 35 strains (53%) exhibited alterations of the mgrB gene, including insertions of different types of mobile elements (IS5-like, IS1F-like, or ISKpn14), nonsilent point mutations, and small intragenic deletions. Four additional strains had a larger deletion of the mgrB locus, while the remaining 27 strains (41%) did not show mgrB alterations. Transcriptional upregulation of the phoQ and pmrK genes (part of the phoPQ and pmrHFIJKLM operon, respectively) was observed in all strains with mgrB alterations. Complementation experiments with a wild-type mgrB gene restored colistin susceptibility and basal expression levels of phoQ and pmrK genes in strains carrying different types of mgrB alterations. The present results suggest that mgrB alteration can be a common mechanism of colistin resistance among KPC-KP in the clinical setting.
Collapse
|
50
|
Resistance to colistin associated with a single amino acid change in protein PmrB among Klebsiella pneumoniae isolates of worldwide origin. Antimicrob Agents Chemother 2014; 58:4762-6. [PMID: 24914122 DOI: 10.1128/aac.00084-14] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A series of colistin-resistant Klebsiella pneumoniae isolates recovered from different countries was investigated in order to evaluate the involvement of the PmrA/PmrB two-component system in this resistance. Six isolates possessed a mutated PmrB protein, which is encoded by the pmrB gene, part of the pmrCAB operon involved in lipopolysaccharide modification. The same amino acid substitution (Thr157Pro) in PmrB was identified in the six isolates. The six isolates belonged to four distinct clonal groups, recovered in South Africa (sequence type 14 [ST14]), Turkey (ST101), and Colombia (ST258 and ST15). Three out of the four clones produced a carbapenemase, OXA-181, OXA-48, or KPC-3, while a single isolate did not produce any carbapenemase. Expression assays revealed an overexpression of the pmrA (70-fold), pmrB (70-fold), pmrC (170-fold), and pmrK (40-fold) genes in the pmrB-mutated isolate compared to expression of the pmrB wild-type isogenic K. pneumoniae isolate, confirming that the PmrB substitution was responsible for increased expression levels of those genes. Complementation assays leading to the expression of a wild-type PmrB protein restored the susceptibility to colistin in all isolates, confirming that the substitution in PmrB was responsible for the resistance phenotype. This study identified a key amino acid located in the PmrB protein as being responsible for the overexpression of pmrCAB and pmrHFIJKLM operons, leading to resistance to colistin.
Collapse
|