1
|
Zhang J, Xu J, Lei H, Liang H, Li X, Li B. The development of variation-based rifampicin resistance in Staphylococcus aureus deciphered through genomic and transcriptomic study. JOURNAL OF HAZARDOUS MATERIALS 2023; 442:130112. [PMID: 36303348 DOI: 10.1016/j.jhazmat.2022.130112] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 09/21/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
Rifampicin (RIF) resistance imposes a challenge on the antimicrobial treatment of pathogen infections. Figuring out the development mechanism of RIF resistance is critical to improving antimicrobial therapy strategy in clinics and biological treatment strategy of RIF polluted sewage in environmental engineering. The RIF resistance development of Staphylococcus aureus (S. aureus) with exposure to RIF at sub-inhibitory concentrations was comprehensively investigated via genomic and transcriptomic approaches in this study. RIF minimal inhibitory concentration (MIC) for S. aureus rapidly increased from 0.032 to 256 mg/L. Membrane permeability decrease, biofilm formation enhancement, and ROS production increase associated with RIF resistance were observed in RIF-induced strains. Through comparative genomic analysis, mutations in rpoB and rpoC were considered to be associated with RIF resistance in S. aureus mutants. Pan-genome-wide single-nucleotide variant analysis indicated that mutations at rpoB-1412, rpoB-1451, and rpoB-1457 were prevalent in 13849 public genomes of S. aureus, while mutations at rpoB-2256, and rpoC-3092 were first discovered in this study. The panorama of adaptative alteration of cellular physiological processes was observed via transcriptomic analysis. The oxidation pressure responses, metabolism, transporters, virulence factors, and multiple steps of DNA and RNA machinery were found to be perturbed by RIF in S. aureus.
Collapse
Affiliation(s)
- Jiayu Zhang
- State Environmental Protection Key Laboratory of Microorganism Application and Risk Control, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; Shenzhen Engineering Research Laboratory for Sludge and Food Waste Treatment and Resource Recovery, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; School of Environment, Tsinghua University, Beijing 100084, China
| | - Jie Xu
- State Environmental Protection Key Laboratory of Microorganism Application and Risk Control, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; Shenzhen Engineering Research Laboratory for Sludge and Food Waste Treatment and Resource Recovery, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Huaxin Lei
- State Environmental Protection Key Laboratory of Microorganism Application and Risk Control, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; Shenzhen Engineering Research Laboratory for Sludge and Food Waste Treatment and Resource Recovery, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; School of Environment, Tsinghua University, Beijing 100084, China
| | - Hebin Liang
- State Environmental Protection Key Laboratory of Microorganism Application and Risk Control, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; Shenzhen Engineering Research Laboratory for Sludge and Food Waste Treatment and Resource Recovery, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; School of Environment, Tsinghua University, Beijing 100084, China
| | - Xiaoyan Li
- State Environmental Protection Key Laboratory of Microorganism Application and Risk Control, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; Shenzhen Engineering Research Laboratory for Sludge and Food Waste Treatment and Resource Recovery, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Bing Li
- State Environmental Protection Key Laboratory of Microorganism Application and Risk Control, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; Shenzhen Engineering Research Laboratory for Sludge and Food Waste Treatment and Resource Recovery, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.
| |
Collapse
|
2
|
Molecular Characterization of Rifampicin-Resistant Staphylococcus aureus Isolates from Retail Foods in China. Antibiotics (Basel) 2021; 10:antibiotics10121487. [PMID: 34943699 PMCID: PMC8698944 DOI: 10.3390/antibiotics10121487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/24/2021] [Accepted: 11/26/2021] [Indexed: 11/17/2022] Open
Abstract
This study investigated the molecular characteristics of rifampin-resistant (RIF-R) Staphylococcus aureus isolates recovered from 4300 retail food samples covering most provincial capitals in China, from 2011 to 2016. Of the 1463 S. aureus enrolled, 149 isolates (142 MSSA and 7 MRSA) were identified as rifampicin-resistant, including 20 high-level (MICs ≥ 8 μg/mL) and 129 low-level (MICs between 2 and 4 μg/mL) rifampicin-resistant strains. Most of the RIF-R S. aureus isolates were resistant to more than three antibiotics. The mutations in the rifampicin resistance-determining region of the rpoB gene were studied in all RIF-R strains. All of the strains presented the mutational change 481 His/Asn and five isolates presented an additional mutation, including 477 Asp/Tyr, 527 Ile/Met, and 466 Leu/Ser, respectively. Thirteen STs and twenty-one spa types were represented, in which five MRSA showed non-type SCCmec and the remaining MRSA belonged to SCCmec type IV-where, ST1-t127 was the predominant type from all of the isolates, while ST398-t034 was the predominant type for the MRSA isolates. In this study, we found that the food-related RIF-R S. aureus may have a unique genetic background selection. However, the scenario regarding the presence of RIF-R S. aureus, especially MRSA, in retail food in China is not favorable and warrants public attention.
Collapse
|
3
|
Rodríguez-Beltrán É, López GD, Anzola JM, Rodríguez-Castillo JG, Carazzone C, Murcia MI. Heterogeneous fitness landscape cues, pknG low expression, and phthiocerol dimycocerosate low production of Mycobacterium tuberculosis ATCC25618 rpoB S450L in enriched broth. Tuberculosis (Edinb) 2021; 132:102156. [PMID: 34891037 DOI: 10.1016/j.tube.2021.102156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 11/23/2021] [Accepted: 11/26/2021] [Indexed: 10/19/2022]
Abstract
Multidrug-resistant tuberculosis (isoniazid/rifampin[RIF]-resistant TB) ravages developing countries. Fitness is critical in clinical outcomes. Previous studies on RIF-resistant TB (RR-TB) showed competitive fitness gains and losses, with rpoB-S450L as the most isolated/fit mutation. This study measured virulence/resistance genes, phthiocerol dimycocerosate (PDIM) levels and their relationship with rpoB S450L ATCC25618 RR-TB strain fitness. After obtaining 10 different RR-TB GenoType MTBDRplus 2.0-genotyped isolates (with nontyped, S441, H445 and S450 positions), only one S450L isolate (R9, rpoB-S450L ATCC 25618, RR 1 μg/mL) was observed, with H445Y being the most common. A competitive fitness in vitro assay with wild-type (wt) ATCC 25618: R9 1:1 in 50 mL Middlebrook 7H9/OADC was performed, and generation time (G) in vitro and relative fitness were obtained. mRNA and PDIM were extracted on log and stationary phases. Fitness decreased in rpoB S450L and H445Y strains, with heterogeneous fitness cues in three biological replicas of rpoB-S450L: one high and two low fitness replicas. S450L strain had significant pknG increase. Compared with S450L, wt-rpoB showed increased polyketide synthase ppsA expression and high PDIM peak measured by HPLC-MS in log phase compared to S450L. This contrasts with previously increased PDIM in other RR-TB isolates.
Collapse
Affiliation(s)
- Édgar Rodríguez-Beltrán
- MicobacUN Group, Microbiology Department, The National University of Colombia (NUC) School of Medicine, AV CR 30 45-03, Bogotá, D.C, 111321, Colombia
| | - Gerson-Dirceu López
- Laboratory of Advanced Analytical Techniques in Natural Products (LATNAP), Chemistry Department, Universidad de los Andes, CR 1 18A-12, Bogotá, D.C, 111711, Colombia
| | - Juan Manuel Anzola
- Corpogen, CR 4 20-41, Bogotá, D.C, 110311, Colombia; Universidad Central, CR 5 21-38, Bogotá, D.C, 110311, Colombia
| | - Juan Germán Rodríguez-Castillo
- MicobacUN Group, Microbiology Department, The National University of Colombia (NUC) School of Medicine, AV CR 30 45-03, Bogotá, D.C, 111321, Colombia
| | - Chiara Carazzone
- Laboratory of Advanced Analytical Techniques in Natural Products (LATNAP), Chemistry Department, Universidad de los Andes, CR 1 18A-12, Bogotá, D.C, 111711, Colombia
| | - Martha I Murcia
- MicobacUN Group, Microbiology Department, The National University of Colombia (NUC) School of Medicine, AV CR 30 45-03, Bogotá, D.C, 111321, Colombia.
| |
Collapse
|
4
|
Wodarz D, Komarova NL. Mutant Evolution in Spatially Structured and Fragmented Expanding Populations. Genetics 2020; 216:191-203. [PMID: 32661138 PMCID: PMC7463292 DOI: 10.1534/genetics.120.303422] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 06/23/2020] [Indexed: 11/18/2022] Open
Abstract
Mutant evolution in spatially structured systems is important for a range of biological systems, but aspects of it still require further elucidation. Adding to previous work, we provide a simple derivation of growth laws that characterize the number of mutants of different relative fitness in expanding populations in spatial models of different dimensionalities. These laws are universal and independent of "microscopic" modeling details. We further study the accumulation of mutants and find that, with advantageous and neutral mutants, more of them are present in spatially structured, compared to well-mixed colonies of the same size. The behavior of disadvantageous mutants is subtle: if they are disadvantageous through a reduction in division rates, the result is the same, and it is the opposite if the disadvantage is due to a death rate increase. Finally, we show that in all cases, the same results are observed in fragmented, nonspatial patch models. This suggests that the patterns observed are the consequence of population fragmentation, and not spatial restrictions per se We provide an intuitive explanation for the complex dependence of disadvantageous mutant evolution on spatial restriction, which relies on desynchronized dynamics in different locations/patches, and plays out differently depending on whether the disadvantage is due to a lower division rate or a higher death rate. Implications for specific biological systems, such as the evolution of drug-resistant cell mutants in cancer or bacterial biofilms, are discussed.
Collapse
Affiliation(s)
- Dominik Wodarz
- Department of Population Health and Disease Prevention, Program in Public Health, Susan and Henry Samueli College of Health Sciences, University of California Irvine, California 92697
- Department of Mathematics, University of California Irvine, California 92697
| | - Natalia L Komarova
- Department of Mathematics, University of California Irvine, California 92697
| |
Collapse
|
5
|
Gelin M, Paoletti J, Nahori MA, Huteau V, Leseigneur C, Jouvion G, Dugué L, Clément D, Pons JL, Assairi L, Pochet S, Labesse G, Dussurget O. From Substrate to Fragments to Inhibitor Active In Vivo against Staphylococcus aureus. ACS Infect Dis 2020; 6:422-435. [PMID: 32017533 DOI: 10.1021/acsinfecdis.9b00368] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Antibiotic resistance is a worldwide threat due to the decreasing supply of new antimicrobials. Novel targets and innovative strategies are urgently needed to generate pathbreaking drug compounds. NAD kinase (NADK) is essential for growth in most bacteria, as it supports critical metabolic pathways. Here, we report the discovery of a new class of antibacterials that targets bacterial NADK. We generated a series of small synthetic adenine derivatives to screen those harboring promising substituents in order to guide efficient fragment linking. This led to NKI1, a new lead compound inhibiting NADK that showed in vitro bactericidal activity against Staphylococcus aureus. In a murine model of infection, NKI1 restricted survival of the bacteria, including methicillin-resistant S. aureus. Collectively, these findings identify bacterial NADK as a potential drug target and NKI1 as a lead compound in the treatment of staphylococcal infections.
Collapse
Affiliation(s)
- Muriel Gelin
- Centre de Biochimie Structurale, CNRS UMR 5048, INSERM U1054, Université Montpellier, 29 route de Navacelles, 34090 Montpellier, France
| | - Julie Paoletti
- Unité de Chimie et Biocatalyse, Institut Pasteur, CNRS UMR3523, 25-28 rue du Docteur Roux, 75015 Paris, France
| | - Marie-Anne Nahori
- Unité des Toxines Bactériennes, Institut Pasteur, 25-28 rue du Docteur Roux, 75015 Paris, France
| | - Valérie Huteau
- Unité de Chimie et Biocatalyse, Institut Pasteur, CNRS UMR3523, 25-28 rue du Docteur Roux, 75015 Paris, France
| | - Clarisse Leseigneur
- Unité de Recherche Yersinia, Institut Pasteur, 25-28 rue du Docteur Roux, 75015 Paris, France
- Université de Paris, Sorbonne Paris Cité, 35 rue Hélène Brion, 75013 Paris, France
| | - Grégory Jouvion
- Unité de Neuropathologie Expérimentale, Institut Pasteur, 25-28 rue du Docteur Roux, 75015 Paris, France
- Sorbonne Université, INSERM UMR S933, Unité de Génétique Médicale, Hôpital Armand Trousseau, APHP, 26 Avenue du Dr Arnold Netter, 75012 Paris, France
| | - Laurence Dugué
- Unité de Chimie et Biocatalyse, Institut Pasteur, CNRS UMR3523, 25-28 rue du Docteur Roux, 75015 Paris, France
| | - David Clément
- Unité de Chimie et Biocatalyse, Institut Pasteur, CNRS UMR3523, 25-28 rue du Docteur Roux, 75015 Paris, France
- Université de Paris, Sorbonne Paris Cité, 35 rue Hélène Brion, 75013 Paris, France
| | - Jean-Luc Pons
- Centre de Biochimie Structurale, CNRS UMR 5048, INSERM U1054, Université Montpellier, 29 route de Navacelles, 34090 Montpellier, France
| | - Liliane Assairi
- INSERM U759, Institut Curie, Centre Universitaire Paris Sud, 91405 Orsay, France
| | - Sylvie Pochet
- Unité de Chimie et Biocatalyse, Institut Pasteur, CNRS UMR3523, 25-28 rue du Docteur Roux, 75015 Paris, France
| | - Gilles Labesse
- Centre de Biochimie Structurale, CNRS UMR 5048, INSERM U1054, Université Montpellier, 29 route de Navacelles, 34090 Montpellier, France
| | - Olivier Dussurget
- Unité de Recherche Yersinia, Institut Pasteur, 25-28 rue du Docteur Roux, 75015 Paris, France
- Université de Paris, Sorbonne Paris Cité, 35 rue Hélène Brion, 75013 Paris, France
| |
Collapse
|
6
|
Maudsdotter L, Ushijima Y, Morikawa K. Fitness of Spontaneous Rifampicin-Resistant Staphylococcus aureus Isolates in a Biofilm Environment. Front Microbiol 2019; 10:988. [PMID: 31134027 PMCID: PMC6514104 DOI: 10.3389/fmicb.2019.00988] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 04/18/2019] [Indexed: 11/25/2022] Open
Abstract
Biofilms of S. aureus accumulate cells resistant to the antibiotic rifampicin. We show here that the accumulation of rifampicin resistant mutants (RifR) in biofilms is not equable but rather is a local event, suggesting that the growth of a few locally emerged mutants is responsible for this. Competition assays demonstrated that, compared to wild-type bacteria, the isolated RifR mutants have a growth advantage in biofilms, but not in planktonic culture. To gain insight into the mechanism of the growth advantage, we tested the involvement of the two-component systems (TCS) that sense and respond to environmental changes. We found that a deletion of SrrAB or NreBC has a drastic effect on the growth advantage of RifR mutants, suggesting the importance of oxygen/respiration responses. All six of the RifR isolates tested showed increased resistance to at least one of the common stresses found in the biofilm environment (i.e., oxidative, nitric acid, and organic acid stress). The RifR mutants also had a growth advantage in a biofilm flow model, which highlights the physiological relevance of our findings.
Collapse
Affiliation(s)
- Lisa Maudsdotter
- Department of Biomedical Science, University of Tsukuba, Tsukuba, Japan
| | - Yuri Ushijima
- Department of Biomedical Science, University of Tsukuba, Tsukuba, Japan
| | - Kazuya Morikawa
- Department of Biomedical Science, University of Tsukuba, Tsukuba, Japan
| |
Collapse
|
7
|
Effect of Macrolide and Rifampin Resistance on the Fitness of Rhodococcus equi. Appl Environ Microbiol 2019; 85:AEM.02665-18. [PMID: 30683740 DOI: 10.1128/aem.02665-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Accepted: 01/16/2019] [Indexed: 12/18/2022] Open
Abstract
Rhodococcus equi is a leading cause of severe pneumonia in foals. Standard treatment is dual antimicrobial therapy with a macrolide and rifampin, but the emergence of macrolide- and rifampin-resistant R. equi isolates is an increasing problem. The objective of this study was to determine the effect of macrolide and/or rifampin resistance on fitness of R. equi Three unique isogenic sets were created, each consisting of four R. equi strains, as follows: a susceptible parent isolate, strains resistant to macrolides or rifampin, and a dual macrolide- and rifampin-resistant strain. Each isogenic set's bacterial growth curve was generated in enriched medium, minimal medium (MM), and minimal medium without iron (MM-I). Bacterial survival in soil was analyzed over 12 months at -20°C, 4°C, 25°C, and 37°C, and the ability of these strains to retain antimicrobial resistance during sequential subculturing was determined. Insertion of the mobile element conferring macrolide resistance had minimal effect on in vitro growth. However, two of three rpoB mutations conferring rifampin resistance resulted in a decreased growth rate in MM. In soil, macrolide- or rifampin-resistant R. equi strains exhibited limited growth compared to that of the susceptible R. equi isolate at all temperatures except -20°C. During subculturing, macrolide resistance was lost over time, and two of three rpoB mutations reverted to the wild-type form. The growth of rifampin-resistant R. equi colonies is delayed under nutrient restriction. In soil, possession of rifampin or macrolide resistance results in decreased fitness. Both macrolide and rifampin resistance can be lost after repeated subculturing.IMPORTANCE This work advances our understanding of the opportunistic environmental pathogen Rhodococcus equi, a disease agent affecting horses and immunocompromised people. R. equi is one of the most common causes of severe pneumonia in young horses. For decades, the standard treatment for R. equi pneumonia in horses has been dual antimicrobial therapy with a macrolide and rifampin; effective alternatives to this combination are lacking. The World Health Organization classifies these antimicrobial agents as critically important for human medicine. Widespread macrolide and rifampin resistance in R. equi isolates is a major emerging problem for the horse-breeding industry and might also adversely impact human health if resistant strains infect people or transfer resistance mechanisms to other pathogens. This study details the impact of antimicrobial resistance on R. equi fitness, a vital step for understanding the ecology and epidemiology of resistant R. equi isolates, and will support development of novel strategies to combat antimicrobial resistance.
Collapse
|
8
|
Guérillot R, Li L, Baines S, Howden B, Schultz MB, Seemann T, Monk I, Pidot SJ, Gao W, Giulieri S, Gonçalves da Silva A, D’Agata A, Tomita T, Peleg AY, Stinear TP, Howden BP. Comprehensive antibiotic-linked mutation assessment by resistance mutation sequencing (RM-seq). Genome Med 2018; 10:63. [PMID: 30165908 PMCID: PMC6117896 DOI: 10.1186/s13073-018-0572-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 07/24/2018] [Indexed: 12/15/2022] Open
Abstract
Mutation acquisition is a major mechanism of bacterial antibiotic resistance that remains insufficiently characterised. Here we present RM-seq, a new amplicon-based deep sequencing workflow based on a molecular barcoding technique adapted from Low Error Amplicon sequencing (LEA-seq). RM-seq allows detection and functional assessment of mutational resistance at high throughput from mixed bacterial populations. The sensitive detection of very low-frequency resistant sub-populations permits characterisation of antibiotic-linked mutational repertoires in vitro and detection of rare resistant populations during infections. Accurate quantification of resistance mutations enables phenotypic screening of mutations conferring pleiotropic phenotypes such as in vivo persistence, collateral sensitivity or cross-resistance. RM-seq will facilitate comprehensive detection, characterisation and surveillance of resistant bacterial populations ( https://github.com/rguerillot/RM-seq ).
Collapse
Affiliation(s)
- Romain Guérillot
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
| | - Lucy Li
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
| | - Sarah Baines
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
| | - Brian Howden
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
| | - Mark B. Schultz
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
- Doherty Applied Microbial Genomics, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
| | - Torsten Seemann
- Doherty Applied Microbial Genomics, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
- Melbourne Bioinformatics, The University of Melbourne, Melbourne, Victoria Australia
| | - Ian Monk
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
| | - Sacha J. Pidot
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
| | - Wei Gao
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
| | - Stefano Giulieri
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
| | - Anders Gonçalves da Silva
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
- Doherty Applied Microbial Genomics, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
| | - Anthony D’Agata
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
| | - Takehiro Tomita
- 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, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria Australia
- Infection and Immunity Theme, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria Australia
| | - Timothy P. Stinear
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
- Doherty Applied Microbial Genomics, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
| | - Benjamin P. Howden
- Department of Microbiology and Immunology, The University of Melbourne at the Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
- Doherty Applied Microbial Genomics, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
- Microbiological Diagnostic Unit Public Health Laboratory, The University of Melbourne at the Peter Doherty Institute for Infection & Immunity, Melbourne, Victoria Australia
- Infectious Diseases Department, Austin Health, Heidelberg, Victoria Australia
| |
Collapse
|
9
|
Convergent Evolution Driven by Rifampin Exacerbates the Global Burden of Drug-Resistant Staphylococcus aureus. mSphere 2018; 3:mSphere00550-17. [PMID: 29404415 PMCID: PMC5784246 DOI: 10.1128/msphere.00550-17] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 12/23/2017] [Indexed: 11/20/2022] Open
Abstract
Mutations in the beta-subunit of bacterial RNA polymerase (RpoB) cause resistance to rifampin (Rifr), a critical antibiotic for treatment of multidrug-resistant Staphylococcus aureus. In vitro studies have shown that RpoB mutations confer decreased susceptibility to other antibiotics, but the clinical relevance is unknown. Here, by analyzing 7,099 S. aureus genomes, we demonstrate that the most prevalent RpoB mutations promote clinically relevant phenotypic plasticity resulting in the emergence of stable S. aureus lineages, associated with increased risk of therapeutic failure through generation of small-colony variants (SCVs) and coresistance to last-line antimicrobial agents. We found eight RpoB mutations that accounted for 93% (469/505) of the total number of Rifr mutations. The most frequently selected amino acid substitutions affecting residue 481 (H481N/Y) were associated with worldwide expansions of Rifr clones spanning decades. Recreating the H481N/Y mutations confirmed no impact on S. aureus growth, but the H481N mutation promoted the emergence of a subpopulation of stable Rifr SCVs with reduced susceptibility to vancomycin and daptomycin. Recreating the other frequent RpoB mutations showed similar impacts on resistance to these last-line agents. We found that 86% of all Rifr isolates in our global sample carried the mutations promoting cross-resistance to vancomycin and 52% to both vancomycin and daptomycin. As four of the most frequent RpoB mutations confer only low-level Rifr, equal to or below some international breakpoints, we recommend decreasing these breakpoints and reconsidering the appropriate use of rifampin to reduce the fixation and spread of these clinically deleterious mutations. IMPORTANCE Increasing antibiotic resistance in the major human pathogen Staphylococcus aureus is threatening the ability to treat patients with these infections. Recent laboratory studies suggest that mutations in the gene commonly associated with rifampin resistance may also impact susceptibility to other last-line antibiotics in S. aureus; however, the overall frequency and clinical impact of these mutations are unknown. By mining a global collection of clinical S. aureus genomes and by mutagenesis experiments, this work reveals that common rifampin-induced rpoB mutations promote phenotypic plasticity that has led to the global emergence of stable, multidrug-resistant S. aureus lineages that are associated with increased risk of therapeutic failure through coresistance to other last-line antimicrobials. We recommend decreasing susceptibility breakpoints for rifampin to allow phenotypic detection of critical rpoB mutations conferring low resistance to rifampin and reconsidering the appropriate use of rifampin to reduce the fixation and spread of these deleterious mutations globally.
Collapse
|
10
|
Ravensdale J, Wong Z, O'Brien F, Gregg K. Efficacy of Antibacterial Peptides Against Peptide-Resistant MRSA Is Restored by Permeabilization of Bacteria Membranes. Front Microbiol 2016; 7:1745. [PMID: 27877159 PMCID: PMC5099250 DOI: 10.3389/fmicb.2016.01745] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 10/19/2016] [Indexed: 11/13/2022] Open
Abstract
Clinical application of antimicrobial peptides (AMPs), as with conventional antibiotics, may be compromised by the development of bacterial resistance. This study investigated AMP resistance in methicillin resistant Staphylococcus aureus, including aspects related to the resilience of the resistant bacteria toward the peptides, the stability of resistance when selection pressures are removed, and whether resistance can be overcome by using the peptides with other membrane-permeabilising agents. Genotypically variant strains of S. aureus became equally resistant to the antibacterial peptides melittin and bac8c when grown in sub-lethal concentrations. Subculture of a melittin-resistant strain without melittin for 8 days lowered the minimal lethal concentration of the peptide from 170 μg ml-1 to 30 μg ml-1. Growth for 24 h in 12 μg ml-1 melittin restored the MLC to 100 μg ml-1. Flow cytometry analysis of cationic fluorophore binding to melittin-naïve and melittin-resistant bacteria revealed that resistance coincided with decreased binding of cationic molecules, suggesting a reduction in nett negative charge on the membrane. Melittin was haemolytic at low concentrations but the truncated analog of melittin, mel12-26, was confirmed to lack haemolytic activity. Although a previous report found that mel12-26 retained full bactericidal activity, we found it to lack significant activity when added to culture medium. However, electroporation in the presence of 50 μg ml-1 of mel12-26, killed 99.3% of the bacteria. Similarly, using a low concentration of the non-ionic detergent Triton X-100 to permeabilize bacteria to mel12-26 markedly increased its bactericidal activity. The observation that bactericidal activity of the non-membranolytic peptide mel12-26 was enhanced when the bacterial membrane was permeablized by detergents or electroporation, suggests that its principal mechanism in reducing bacterial survival may be through interaction with intracellular organelles or processes. Additionally, our results showed that the haemolytic peptide bac8c, had increased antibacterial activity at non-haemolytic concentrations when used with membrane-permeabilizing surfactants.
Collapse
Affiliation(s)
- Joshua Ravensdale
- School of Biomedical Science, Faculty of Health and Curtin Health Innovation Research Institute, Curtin University, Bentley WA, Australia
| | - Zachary Wong
- School of Biomedical Science, Faculty of Health and Curtin Health Innovation Research Institute, Curtin University, Bentley WA, Australia
| | - Frances O'Brien
- School of Biomedical Science, Faculty of Health and Curtin Health Innovation Research Institute, Curtin University, BentleyWA, Australia; Australian Collaborative Centre for Enterococcal and Staphylococcal Species (ACCESS) Typing and Research, Curtin University and PathWest Microbiology, Royal Perth Hospital, PerthWA, Australia
| | - Keith Gregg
- School of Biomedical Science, Faculty of Health and Curtin Health Innovation Research Institute, Curtin University, Bentley WA, Australia
| |
Collapse
|
11
|
Guillard T, Pons S, Roux D, Pier GB, Skurnik D. Antibiotic resistance and virulence: Understanding the link and its consequences for prophylaxis and therapy. Bioessays 2016; 38:682-93. [PMID: 27248008 DOI: 10.1002/bies.201500180] [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] [Indexed: 12/21/2022]
Abstract
"Antibiotic resistance is usually associated with a fitness cost" is frequently accepted as common knowledge in the field of infectious diseases. However, with the advances in high-throughput DNA sequencing that allows for a comprehensive analysis of bacterial pathogenesis at the genome scale, including antibiotic resistance genes, it appears that this paradigm might not be as solid as previously thought. Recent studies indicate that antibiotic resistance is able to enhance bacterial fitness in vivo with a concomitant increase in virulence during infections. As a consequence, strategies to minimize antibiotic resistance turn out to be not as simple as initially believed. Indeed, decreased antibiotic use may not be sufficient to let susceptible strains outcompete the resistant ones. Here, we put in perspective these findings and review alternative approaches, such as preventive and therapeutic anti-bacterial immunotherapies that have the potential to by-pass the classic antibiotics.
Collapse
Affiliation(s)
- Thomas Guillard
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,Laboratoire de Bactériologie-Virologie-Hygiène hospitalière, Hôpital Robert Debré - CHU de Reims, UFR de Médecine, Université de Reims Champagne-Ardenne, Reims, France
| | - Stéphanie Pons
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Damien Roux
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.,INSERM, IAME, UMR 1137, Paris, France.,Univ Paris Diderot, IAME, UMR 1137, Sorbonne Paris Cité, Paris, France.,AP-HP, Hôpital Louis Mourier, Service de Réanimation Médico-Chirurgicale, Colombes, France
| | - Gerald B Pier
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - David Skurnik
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
12
|
Revest M, Jacqueline C, Boudjemaa R, Caillon J, Le Mabecque V, Breteche A, Steenkeste K, Tattevin P, Potel G, Michelet C, Fontaine-Aupart MP, Boutoille D. New in vitro and in vivo models to evaluate antibiotic efficacy in Staphylococcus aureus prosthetic vascular graft infection. J Antimicrob Chemother 2016; 71:1291-9. [PMID: 26851611 DOI: 10.1093/jac/dkv496] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 12/19/2015] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVE Prosthetic vascular graft infection (PVGI) is an emerging disease, mostly caused by staphylococci, with limited data regarding efficacy of current antistaphylococcal agents. We aimed to assess the efficacy of different antibiotic regimens. METHODS Six different strains of MSSA and MRSA were used. We compared results of minimal biofilm inhibitory and eradicating concentrations (MBICs and MBECs) obtained with a Calgary Biofilm Pin Lid Device (CBPD) with those yielded by an original Dacron(®)-related minimal inhibitory and eradicating concentration measure model. We then used a murine model of Staphylococcus aureus vascular prosthetic material infection to evaluate efficacy of different antibiotic regimens: vancomycin and daptomycin combined or not with rifampicin for MRSA and the same groups with cloxacillin and cloxacillin combined with rifampicin for MSSA. RESULTS We demonstrated that classical measures of MBICs and MBECs obtained with a CPBD could overestimate the decrease in antibiotic susceptibility in material-related infections and that the nature of the support used might influence the measure of biofilm susceptibility, since results yielded by our Dacron(®)-related minimal eradicating assay were lower than those found with a plastic device. In our in vivo model, we showed that daptomycin was significantly more bactericidal than comparators for some strains of MRSA or MSSA but not for all. For the majority of strains, it was as efficient as comparators. The addition of rifampicin to daptomycin did not enhance daptomycin efficacy. CONCLUSIONS Despite the heterogeneity of results according to bacterial strains, these innovative models represent an option to better evaluate the in vitro efficacy of antibiotics on Dacron(®)-related biofilm S. aureus infections, and to screen different antibiotic regimens in a mouse model of PVGIs.
Collapse
Affiliation(s)
- M Revest
- Université Nantes, Faculté Médecine EA3826 Nantes, France CHU Rennes Infectious Diseases and Intensive Care Unit, Pontchaillou Hospital, 35033 Rennes Cedex, France CIC Inserm 1414, Rennes 1 University, Pontchaillou Hospital, 35033 Rennes Cedex, France
| | - C Jacqueline
- Université Nantes, Faculté Médecine EA3826 Nantes, France
| | - R Boudjemaa
- Institut des Sciences Moléculaires Orsay, CNRS, Université Paris-Sud, 91405 Orsay, France
| | - J Caillon
- Université Nantes, Faculté Médecine EA3826 Nantes, France
| | - V Le Mabecque
- Université Nantes, Faculté Médecine EA3826 Nantes, France
| | - A Breteche
- Université Nantes, Faculté Médecine EA3826 Nantes, France
| | - K Steenkeste
- Institut des Sciences Moléculaires Orsay, CNRS, Université Paris-Sud, 91405 Orsay, France
| | - P Tattevin
- CHU Rennes Infectious Diseases and Intensive Care Unit, Pontchaillou Hospital, 35033 Rennes Cedex, France CIC Inserm 1414, Rennes 1 University, Pontchaillou Hospital, 35033 Rennes Cedex, France
| | - G Potel
- Université Nantes, Faculté Médecine EA3826 Nantes, France
| | - C Michelet
- CHU Rennes Infectious Diseases and Intensive Care Unit, Pontchaillou Hospital, 35033 Rennes Cedex, France CIC Inserm 1414, Rennes 1 University, Pontchaillou Hospital, 35033 Rennes Cedex, France
| | - M P Fontaine-Aupart
- Institut des Sciences Moléculaires Orsay, CNRS, Université Paris-Sud, 91405 Orsay, France
| | - D Boutoille
- Université Nantes, Faculté Médecine EA3826 Nantes, France CHU Nantes, Infectious Diseases Unit, Hôtel Dieu, Nantes, France
| |
Collapse
|
13
|
Influence of antibiotic pressure on bacterial bioluminescence, with emphasis on Staphylococcus aureus. Int J Antimicrob Agents 2015; 46:713-7. [DOI: 10.1016/j.ijantimicag.2015.09.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 09/13/2015] [Accepted: 09/15/2015] [Indexed: 12/19/2022]
|
14
|
Melnyk AH, Wong A, Kassen R. The fitness costs of antibiotic resistance mutations. Evol Appl 2014; 8:273-83. [PMID: 25861385 PMCID: PMC4380921 DOI: 10.1111/eva.12196] [Citation(s) in RCA: 372] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 07/10/2014] [Indexed: 01/07/2023] Open
Abstract
Antibiotic resistance is increasing in pathogenic microbial populations and is thus a major threat to public health. The fate of a resistance mutation in pathogen populations is determined in part by its fitness. Mutations that suffer little or no fitness cost are more likely to persist in the absence of antibiotic treatment. In this review, we performed a meta-analysis to investigate the fitness costs associated with single mutational events that confer resistance. Generally, these mutations were costly, although several drug classes and species of bacteria on average did not show a cost. Further investigations into the rate and fitness values of compensatory mutations that alleviate the costs of resistance will help us to better understand both the emergence and management of antibiotic resistance in clinical settings.
Collapse
Affiliation(s)
- Anita H Melnyk
- Centre for Advanced Research in Environmental Genomics, Department of Biology, University of Ottawa Ottawa, ON, Canada
| | - Alex Wong
- Department of Biology, Carleton University Ottawa, ON, Canada
| | - Rees Kassen
- Centre for Advanced Research in Environmental Genomics, Department of Biology, University of Ottawa Ottawa, ON, Canada
| |
Collapse
|
15
|
Koch A, Mizrahi V, Warner DF. The impact of drug resistance on Mycobacterium tuberculosis physiology: what can we learn from rifampicin? Emerg Microbes Infect 2014; 3:e17. [PMID: 26038512 PMCID: PMC3975073 DOI: 10.1038/emi.2014.17] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Revised: 12/12/2013] [Accepted: 12/30/2013] [Indexed: 01/08/2023]
Abstract
The emergence of drug-resistant pathogens poses a major threat to public health. Although influenced by multiple factors, high-level resistance is often associated with mutations in target-encoding or related genes. The fitness cost of these mutations is, in turn, a key determinant of the spread of drug-resistant strains. Rifampicin (RIF) is a frontline anti-tuberculosis agent that targets the rpoB-encoded β subunit of the DNA-dependent RNA polymerase (RNAP). In Mycobacterium tuberculosis (Mtb), RIF resistance (RIF(R)) maps to mutations in rpoB that are likely to impact RNAP function and, therefore, the ability of the organism to cause disease. However, while numerous studies have assessed the impact of RIF(R) on key Mtb fitness indicators in vitro, the consequences of rpoB mutations for pathogenesis remain poorly understood. Here, we examine evidence from diverse bacterial systems indicating very specific effects of rpoB polymorphisms on cellular physiology, and consider these observations in the context of Mtb. In addition, we discuss the implications of these findings for the propagation of clinically relevant RIF(R) mutations. While our focus is on RIF, we also highlight results which suggest that drug-independent effects might apply to a broad range of resistance-associated mutations, especially in an obligate pathogen increasingly linked with multidrug resistance.
Collapse
Affiliation(s)
- Anastasia Koch
- Medical Research Council/National Health Laboratory Service/University of Cape Town Molecular Mycobacteriology Research Unit, Department of Science and Technology/National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, Institute of Infectious Disease and Molecular Medicine and Department of Clinical Laboratory Sciences, University of Cape Town , Cape Town 7701, South Africa
| | - Valerie Mizrahi
- Medical Research Council/National Health Laboratory Service/University of Cape Town Molecular Mycobacteriology Research Unit, Department of Science and Technology/National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, Institute of Infectious Disease and Molecular Medicine and Department of Clinical Laboratory Sciences, University of Cape Town , Cape Town 7701, South Africa
| | - Digby F Warner
- Medical Research Council/National Health Laboratory Service/University of Cape Town Molecular Mycobacteriology Research Unit, Department of Science and Technology/National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, Institute of Infectious Disease and Molecular Medicine and Department of Clinical Laboratory Sciences, University of Cape Town , Cape Town 7701, South Africa
| |
Collapse
|
16
|
Lim KT, Teh CSJ, Yusof MYM, Thong KL. Mutations in rpoB and fusA cause resistance to rifampicin and fusidic acid in methicillin-resistant Staphylococcus aureus strains from a tertiary hospital in Malaysia. Trans R Soc Trop Med Hyg 2013; 108:112-8. [PMID: 24336696 DOI: 10.1093/trstmh/trt111] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The prevalence of resistance to rifampicin and fusidic acid among Malaysian strains of methicillin-resistant Staphylococcus aureus (MRSA) is increasing. This study aimed to determine the mechanisms of rifampicin and fusidic acid resistance and the genetic diversity of MRSA strains from a Malaysian tertiary hospital. METHODS Minimum inhibitory concentrations (MIC) for 21 MRSA strains were determined by agar dilution test and Etest. The resistance genes, staphylococcal chromosome cassette mec (SCCmec) types, multilocus-sequence typing (MLST) types and spa types, were determined by PCR and DNA sequencing. RESULTS MIC for rifampicin and fusidic acid resistance ranged from <1 to 8 µg/ml and from <1 to 256 µg/ml, respectively. A double mutation (484Arg/His and 517Glu/Gln) in rpoB causes high rifampicin resistance while a mutational change (461Leu/Lys) in fusA was observed in seven strains highly resistant to fusidic acid. Five of the seven were also resistant to rifampicin (MIC 8 µg/ml) and carried a mutated rpoB gene (484Arg/His). No other acquired fusidic acid resistance gene (fusB, fusC or fusD) was detected. Most (14/21) of the strains belonged to clone ST239-III-t037. Three belonged to ST22-IV-t1378 and the remaining four to ST239-III-t2029, ST239-III-t421, ST1178-IV-t1107 and ST241-III-t363, respectively. CONCLUSIONS The study showed that both rifampicin and fusidic acid resistance was associated with mutational change in rpoB and fusA, respectively. All rifampicin-resistant strains were from the same clone ST239-III-t037 whereas strains resistant to fusidic acid were genetically more diverse.
Collapse
Affiliation(s)
- King-Ting Lim
- Institute of Biological Science, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | | | | | | |
Collapse
|
17
|
Kim MS, Morales W, Hani AA, Kim S, Kim G, Weitsman S, Chang C, Pimentel M. The effect of rifaximin on gut flora and Staphylococcus resistance. Dig Dis Sci 2013; 58:1676-82. [PMID: 23589147 DOI: 10.1007/s10620-013-2675-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 03/27/2013] [Indexed: 12/11/2022]
Abstract
AIM Rifaximin is a non-absorbed antibiotic relative of rifampicin. The location of effect and staphylococcal resistance are two recent potential concerns with rifaximin. In this study we evaluate the location of effect of rifaximin as well as the development of staphylococcal rifampicin resistance. METHODS Rats were divided into three groups. Group 1 gavaged for 10 days with PBS, group 2 gavaged with rifaximin for 10 days, and group 3 gavaged with rifaximin for 10 days and housed for 30 days. In each group, stool was collected daily for quantitative culture of Staphylococcus spp. and coliforms. After euthanasia luminal bacterial counts were determined at multiple gut locations by qPCR. Rifampicin susceptibility was tested on Staphylococcus pre and post rifaximin. RESULTS At baseline, rats had a median of 2.90 × 10(6) cfu/ml Staphylococcus spp. in stool. After 10 days of rifaximin, this dropped to 1.20 × 10(5) cfu/ml (P < 0.01). With coliform counts, rats had a median of 1.86 × 10(4) cfu/ml at baseline which dropped to 2.2 × 10(3) cfu/ml (P < 0.01) after rifaximin. After cessation of rifaximin, coliform counts recovered within 3 days. When examining the total bacterial counts by qPCR, rifaximin reduced small bowel bacterial levels, but not colon. This reduction was sustained for 30 days. No colonies of Staphylococcus became resistant and only one colony was intermediate. The mean inhibitory concentration for rifampicin was not different before and after rifaximin. CONCLUSION Staphylococcal spp. fail to demonstrate resistance to rifampicin after rifaximin. The transient reductions in stool coliform counts recover while rifaximin appears to produce durable reductions in duodenal bacteria.
Collapse
Affiliation(s)
- Mi-Sung Kim
- Division of Gastroenterology, Cheongju St. Mary's Hospital, Cheongju, Korea
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Gao W, Cameron DR, Davies JK, Kostoulias X, Stepnell J, Tuck KL, Yeaman MR, Peleg AY, Stinear TP, Howden BP. The RpoB H₄₈₁Y rifampicin resistance mutation and an active stringent response reduce virulence and increase resistance to innate immune responses in Staphylococcus aureus. J Infect Dis 2012; 207:929-39. [PMID: 23255563 DOI: 10.1093/infdis/jis772] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The occurrence of mutations in methicillin-resistant Staphylococcus aureus (MRSA) during persistent infection leads to antimicrobial resistance but may also impact host-pathogen interactions. Here, we investigate the host-pathogen consequences of 2 mutations arising in clinical MRSA during persistent infection: RpoB H₄₈₁Y, which is linked to rifampicin resistance, and RelA F₁₂₈Y, which is associated with an active stringent response. Allelic exchange experiments showed that both mutations cause global transcriptional changes, leading to upregulation of capsule production, with attenuated virulence in a murine bacteremia model and reduced susceptibility to both antimicrobial peptides and whole-blood killing. Disruption of capsule biosynthesis reversed these impacts on innate immune function. These data clearly link MRSA persistence and reduced virulence to the same mechanisms that alter antimicrobial susceptibility. Our study highlights the wider consequences of suboptimal antimicrobial use, where drug resistance and immune escape mechanisms coevolve, thus increasing the likelihood of treatment failure.
Collapse
Affiliation(s)
- Wei Gao
- Infectious Diseases Department, Austin Centre for Infection Research, University of Melbourne, Australia
| | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Fenton M, Casey PG, Hill C, Gahan CG, Ross RP, McAuliffe O, O'Mahony J, Maher F, Coffey A. The truncated phage lysin CHAP(k) eliminates Staphylococcus aureus in the nares of mice. Bioeng Bugs 2011; 1:404-7. [PMID: 21468207 DOI: 10.4161/bbug.1.6.13422] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Revised: 08/25/2010] [Accepted: 08/27/2010] [Indexed: 11/19/2022] Open
Abstract
The endolysin LysK derived from staphylococcal phage K has previously been shown to have two enzymatic domains, one of which is an N-acetylmuramoyl-L-alanine amidase and the other a cysteine/histidine-dependant amidohydrolase/peptidase designated CHAP(k). The latter, when cloned as a single-domain truncated enzyme, is conveniently overexpressed in a highly-soluble form. This enzyme was shown to be highly active in vitro against live cell suspensions of S. aureus. In the current study, the IVIS imaging system was used to demonstrate the effective elimination of a lux labeled S. aureus from the nares of BALB/c mice.
Collapse
Affiliation(s)
- Mark Fenton
- Department of Biological Sciences, Cork Institute of Technology, Cork, Ireland
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Martínez JL, Baquero F, Andersson DI. Beyond serial passages: new methods for predicting the emergence of resistance to novel antibiotics. Curr Opin Pharmacol 2011; 11:439-45. [PMID: 21835695 DOI: 10.1016/j.coph.2011.07.005] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Revised: 07/06/2011] [Accepted: 07/13/2011] [Indexed: 11/19/2022]
Abstract
Market launching of a new antibiotic requires knowing in advance its benefits and possible risks, and among them how rapidly resistance will emerge and spread among bacterial pathogens. This information is not only useful from a public health point of view, but also for pharmaceutical industry, in order to reduce potential waste of resources in the development of a compound that might be discontinued at the short term because of resistance development. Most assays currently used for predicting the emergence of resistance are based on culturing the target bacteria by serial passages in the presence of increasing concentrations of antibiotics. Whereas these assays may be valuable for identifying mutations that might cause resistance, they are not useful to establish how fast resistance might appear, neither to address the risk of spread of resistance genes by horizontal gene transfer. In this article, we review recent information pertinent for a more accurate prediction on the emergence and dispersal of antibiotic resistance.
Collapse
Affiliation(s)
- José Luis Martínez
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Darwin 3, Cantoblanco, Madrid, Spain.
| | | | | |
Collapse
|
21
|
Abstract
According to World Health Organization estimates, infectious organisms are responsible for approximately one in four deaths worldwide. Animal models play an essential role in the development of vaccines and therapeutic agents but large numbers of animals are required to obtain quantitative microbiological data by tissue sampling. Biophotonic imaging (BPI) is a highly sensitive, nontoxic technique based on the detection of visible light, produced by luciferase-catalysed reactions (bioluminescence) or by excitation of fluorescent molecules, using sensitive photon detectors. The development of bioluminescent/fluorescent microorganisms therefore allows the real-time noninvasive detection of microorganisms within intact living animals. Multiple imaging of the same animal throughout an experiment allows disease progression to be followed with extreme accuracy, reducing the number of animals required to yield statistically meaningful data. In the study of infectious disease, the use of BPI is becoming widespread due to the novel insights it can provide into established models, as well as the impact of the technique on two of the guiding principles of using animals in research, namely reduction and refinement. Here, we review the technology of BPI, from the instrumentation through to the generation of a photonic signal, and illustrate how the technique is shedding light on infection dynamics in vivo.
Collapse
Affiliation(s)
- Nuria Andreu
- Department of Medicine, Imperial College London, London, UK
| | | | | |
Collapse
|
22
|
Engelsman AF, Saldarriaga-Fernandez IC, Nejadnik MR, van Dam GM, Francis KP, Ploeg RJ, Busscher HJ, van der Mei HC. The risk of biomaterial-associated infection after revision surgery due to an experimental primary implant infection. BIOFOULING 2010; 26:761-7. [PMID: 20737327 DOI: 10.1080/08927014.2010.515027] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The fate of secondary biomaterial implants was determined by bio-optical imaging and plate counting, after antibiotic treatment of biomaterials-associated-infection (BAI) and surgical removal of an experimentally infected, primary implant. All primary implants and tissue samples from control mice showed bioluminescence and were culture-positive. In an antibiotic treated group, no bioluminescence was detected and only 20% of all primary implants and no tissue samples were culture-positive. After revision surgery, bioluminescence was detected in all control mice. All the implants and 80% of all tissue samples were culture-positive. In contrast, in the antibiotic treated group, 17% of all secondary implants and 33% of all tissue samples were culture-positive, despite antibiotic treatment. The study illustrates that due to the BAI of a primary implant, the infection risk of biomaterial implants is higher in revision surgery than in primary surgery, emphasizing the need for full clearance of the infection, as well as from surrounding tissues prior to implantation of a secondary implant.
Collapse
Affiliation(s)
- Anton F Engelsman
- Department of BioMedical Engineering, University Medical Center Groningen and University of Groningen, The Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Andersson DI, Hughes D. Antibiotic resistance and its cost: is it possible to reverse resistance? Nat Rev Microbiol 2010; 8:260-71. [PMID: 20208551 DOI: 10.1038/nrmicro2319] [Citation(s) in RCA: 1443] [Impact Index Per Article: 103.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Most antibiotic resistance mechanisms are associated with a fitness cost that is typically observed as a reduced bacterial growth rate. The magnitude of this cost is the main biological parameter that influences the rate of development of resistance, the stability of the resistance and the rate at which the resistance might decrease if antibiotic use were reduced. These findings suggest that the fitness costs of resistance will allow susceptible bacteria to outcompete resistant bacteria if the selective pressure from antibiotics is reduced. Unfortunately, the available data suggest that the rate of reversibility will be slow at the community level. Here, we review the factors that influence the fitness costs of antibiotic resistance, the ways by which bacteria can reduce these costs and the possibility of exploiting them.
Collapse
Affiliation(s)
- Dan I Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, BOX 582, SE-751 23, Uppsala, Sweden.
| | | |
Collapse
|
24
|
Kempf I, Zeitouni S. [The cost of antibiotic resistance: analysis and consequences]. ACTA ACUST UNITED AC 2009; 60:e9-14. [PMID: 19942376 DOI: 10.1016/j.patbio.2009.10.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Accepted: 10/27/2009] [Indexed: 11/16/2022]
Abstract
Antimicrobial resistance, either by mutation or acquisition of resistance determinants harbored by mobile genetic elements, may confer a biological cost for the bacteria. This biological cost can be evaluated by comparing the resistant mutant to the wild susceptible strain, in the absence of antibiotic selection. This fitness cost can affect the growth rate in vitro or the survival in the host or in the environment or the virulence capacity. Various studies have evidenced this cost, either in vitro or in vivo, in different analysis models. However, bacteria can evolve and adapt to reduce this cost, by compensatory mutations or fine regulation of resistance expression. This compensatory evolution allows resistant bacteria to persist even in the absence of antibiotic selection pressure.
Collapse
Affiliation(s)
- I Kempf
- Unite´ mycoplasmologie-bacteriologie, Zoopole-les-Croix, 22440 Ploufragan, France.
| | | |
Collapse
|
25
|
Abstract
Whole body biophotonic imaging (BPI) is a technique that has contributed significantly to the way researchers study bacterial pathogens and develop pre-clinical treatments to combat their ensuing infections in vivo. Not only does this approach allow disease profiles and drug efficacy studies to be conducted non-destructively in live animals over the entire course of the disease, but in many cases, it enables investigators to observe disease profiles that could otherwise easily be missed using conventional methodologies. The principles of this technique are that bacterial pathogens engineered to express bioluminescence (visible light) can be readily monitored from outside of the living animal using specialized low-light imaging equipment, enabling their movement, expansion and treatment to be seen completely non-invasively. Moreover, because the same group of animals can be imaged at each time-point throughout the study, the overall number of animals used is dramatically reduced, saving lives, time, and money. Also, as each animal acts as its own control over time, the issues associated with animal-to-animal variation are circumvented, thus improving the quality of the biostatistical data generated. The ability to monitor infections in vivo in a longitudinal fashion is especially appealing to assess chronic infections such as those involving implanted devices. Typically, bacteria grow as biofilms on these foreign bodies and are reputably difficult to monitor with conventional methods. Because of the non-destructive and non-invasive nature of BPI, the procedure can be performed repeatedly in the same animal, allowing the biofilm to be studied in situ without detachment or disturbance. This ability not only allows unique patterns of disease relapse to be seen following termination of antibiotic therapy but also in vivo resistance development during prolonged treatment, both of which are common occurrences with device-related infections. This chapter describes the bioluminescent engineering of both Gram-positive and Gram-negative bacteria and overviews their use in device-associated infections in several anatomical sites in a variety of animal models.
Collapse
|
26
|
Frischknecht F, Amino R, Franke-Fayard B, Janse C, Waters A, Ménard R. Imaging Parasites in Vivo. IMAGING CELLULAR AND MOLECULAR BIOLOGICAL FUNCTIONS 2007. [DOI: 10.1007/978-3-540-71331-9_12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
27
|
Andersson DI. The biological cost of mutational antibiotic resistance: any practical conclusions? Curr Opin Microbiol 2006; 9:461-5. [PMID: 16890008 DOI: 10.1016/j.mib.2006.07.002] [Citation(s) in RCA: 305] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2006] [Accepted: 07/21/2006] [Indexed: 10/24/2022]
Abstract
A key parameter influencing the rate and trajectory of the evolution of antibiotic resistance is the fitness cost of resistance. Recent studies have demonstrated that antibiotic resistance, whether caused by target alteration or by other mechanisms, generally confers a reduction in fitness expressed as reduced growth, virulence or transmission. These findings imply that resistance might be reversible, provided antibiotic use is reduced. However, several processes act to stabilize resistance, including compensatory evolution where the fitness cost is ameliorated by additional mutation without loss of resistance, the rare occurrence of cost-free resistance mechanisms and genetic linkage or co-selection between the resistance markers and other selected markers. Conceivably we can use this knowledge to rationally choose and design targets and drugs where the costs of resistance are the highest, and where the likelihood of compensation is the lowest.
Collapse
Affiliation(s)
- Dan I Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, Box 582, S-751 23 Uppsala, Sweden.
| |
Collapse
|
28
|
Murphy CK, Mullin S, Osburne MS, van Duzer J, Siedlecki J, Yu X, Kerstein K, Cynamon M, Rothstein DM. In vitro activity of novel rifamycins against rifamycin-resistant Staphylococcus aureus. Antimicrob Agents Chemother 2006; 50:827-34. [PMID: 16495239 PMCID: PMC1426431 DOI: 10.1128/aac.50.3.827-834.2006] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
We describe novel rifamycin derivatives (new chemical entities [NCEs]) that retain significant activity against a comprehensive collection of Staphylococcus aureus strains that are resistant to rifamycins. This collection of resistant strains contains 21 of the 26 known single-amino-acid alterations in RpoB, the target of rifamycins. Some NCEs also demonstrated a lower frequency of resistance development than rifampin and rifalazil in S. aureus as measured in a resistance emergence test. When assayed for activity against the strongest rifamycin-resistant mutants, several NCEs had MICs of 2 microg/ml, in contrast to MICs of rifampin and rifalazil, which were 512 microg/ml for the same strains. The properties of these NCEs therefore demonstrate a significant improvement over those of earlier rifamycins, which have been limited primarily to combination therapy due to resistance development, and suggest a potential use of these NCEs for monotherapy in several clinical indications.
Collapse
|