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Sapula SA, Hart BJ, Siderius NL, Amsalu A, Blaikie JM, Venter H. Multidrug-resistant Stenotrophomonas maltophilia in residential aged care facilities: An emerging threat. Microbiologyopen 2024; 13:e1409. [PMID: 38682784 PMCID: PMC11057060 DOI: 10.1002/mbo3.1409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 03/20/2024] [Accepted: 04/16/2024] [Indexed: 05/01/2024] Open
Abstract
Stenotrophomonas maltophilia is a multidrug-resistant (MDR), Gram-negative bacterium intrinsically resistant to beta-lactams, including last-resort carbapenems. As an opportunistic pathogen, it can cause serious healthcare-related infections. This study assesses the prevalence, resistance profiles, and genetic diversity of S. maltophilia isolated from residential aged care facilities (RACFs). RACFs are known for their overuse and often inappropriate use of antibiotics, creating a strong selective environment that favors the development of bacterial resistance. The study was conducted on 73 S. maltophilia isolates recovered from wastewater and facility swab samples obtained from three RACFs and a retirement village. Phenotypic and genotypic assessments of the isolates revealed high carbapenem resistance, exemplifying their intrinsic beta-lactam resistance. Alarmingly, 49.3% (36/73) of the isolates were non-wild type for colistin, with minimum inhibitory concentration values of > 4 mg/L, and 11.0% (8/73) were resistant to trimethoprim-sulfamethoxazole. No resistance mechanisms were detected for either antimicrobial. Genotypic assessment of known lineages revealed isolates clustering with Sm17 and Sm18, lineages not previously reported in Australia, suggesting the potential ongoing spread of MDR S. maltophilia. Lastly, although only a few isolates were biocide tolerant (2.7%, 2/73), their ability to grow in high concentrations (64 mg/L) of triclosan is concerning, as it may be selecting for their survival and continued dissemination.
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Affiliation(s)
- Sylvia A. Sapula
- Health and Biomedical Innovation, UniSA Clinical and Health SciencesUniversity of South AustraliaAdelaideSouth AustraliaAustralia
| | - Bradley J. Hart
- Health and Biomedical Innovation, UniSA Clinical and Health SciencesUniversity of South AustraliaAdelaideSouth AustraliaAustralia
| | - Naomi L. Siderius
- Health and Biomedical Innovation, UniSA Clinical and Health SciencesUniversity of South AustraliaAdelaideSouth AustraliaAustralia
| | - Anteneh Amsalu
- Health and Biomedical Innovation, UniSA Clinical and Health SciencesUniversity of South AustraliaAdelaideSouth AustraliaAustralia
- Department of Medical MicrobiologyUniversity of GondarGondarEthiopia
| | - Jack M. Blaikie
- Health and Biomedical Innovation, UniSA Clinical and Health SciencesUniversity of South AustraliaAdelaideSouth AustraliaAustralia
| | - Henrietta Venter
- Health and Biomedical Innovation, UniSA Clinical and Health SciencesUniversity of South AustraliaAdelaideSouth AustraliaAustralia
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Mikhailovich V, Heydarov R, Zimenkov D, Chebotar I. Stenotrophomonas maltophilia virulence: a current view. Front Microbiol 2024; 15:1385631. [PMID: 38741741 PMCID: PMC11089167 DOI: 10.3389/fmicb.2024.1385631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 04/15/2024] [Indexed: 05/16/2024] Open
Abstract
Stenotrophomonas maltophilia is an opportunistic pathogen intrinsically resistant to multiple and broad-spectrum antibiotics. Although the bacterium is considered a low-virulence pathogen, it can cause various severe diseases and contributes significantly to the pathogenesis of multibacterial infections. During the COVID-19 pandemic, S. maltophilia has been recognized as one of the most common causative agents of respiratory co-infections and bacteremia in critically ill COVID-19 patients. The high ability to adapt to unfavorable environments and new habitat niches, as well as the sophisticated switching of metabolic pathways, are unique mechanisms that attract the attention of clinical researchers and experts studying the fundamental basis of virulence. In this review, we have summarized the current knowledge on the molecular aspects of S. maltophilia virulence and putative virulence factors, partially touched on interspecific bacterial interactions and iron uptake systems in the context of virulence, and have not addressed antibiotic resistance.
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Affiliation(s)
- Vladimir Mikhailovich
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Rustam Heydarov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Danila Zimenkov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Igor Chebotar
- Pirogov Russian National Research Medical University, Moscow, Russia
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Hu EW, Lu HF, Lin YT, Yang TC, Li LH. Modulatory role of SmeQ in SmeYZ efflux pump-involved functions in Stenotrophomonas maltophilia. J Antimicrob Chemother 2024; 79:383-390. [PMID: 38134316 DOI: 10.1093/jac/dkad392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023] Open
Abstract
BACKGROUND SmeYZ is a constitutively expressed efflux pump in Stenotrophomonas maltophilia. Previous studies demonstrated that: (i) smeYZ inactivation causes compromised swimming, oxidative stress tolerance and aminoglycoside resistance; and (ii) the ΔsmeYZ-mediated pleiotropic defects, except aminoglycoside susceptibility, result from up-regulation of entSCEBB'FA and sbiAB operons, and decreased intracellular iron level. OBJECTIVES To elucidate the modulatory role of SmeQ, a novel cytoplasmic protein, in ΔsmeYZ-mediated pleiotropic defects. METHODS The presence of operons was verified using RT-PCR. The role of SmeQ in ΔsmeYZ-mediated pleiotropic defects was assessed using in-frame deletion mutants and functional assays. A bacterial adenylate cyclase two-hybrid assay was used to investigate the protein-protein interactions. Gene expression was quantified using quantitative RT-PCR (RT-qPCR). RESULTS SmeYZ and the downstream smeQ formed an operon. SmeQ inactivation in the WT KJ decreased aminoglycoside resistance but did not affect swimming and tolerance to oxidative stress or iron depletion. However, smeQ inactivation in the smeYZ mutant rescued the ΔsmeYZ-mediated pleiotropic defects, except for aminoglycoside susceptibility. In the WT KJ, SmeQ positively modulated SmeYZ pump function by transcriptionally up-regulating the smeYZQ operon. Nevertheless, in the smeYZ mutant, SmeQ exerted its modulatory role by up-regulating entSCEBB'FA and sbiAB operons, decreasing intracellular iron levels, and causing ΔsmeYZ-mediated pleiotropic defects, except for aminoglycoside susceptibility. CONCLUSIONS SmeQ is the first small protein identified to be involved in efflux pump function in S. maltophilia. It exerts modulatory effect by transcriptionally altering the expression of target genes, which are the smeYZQ operon in the WT KJ, and smeYZQ, entSCEBB'FA and sbiAB operons in smeYZ mutants.
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Affiliation(s)
- En-Wei Hu
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, Republic of China
| | - Hsu-Feng Lu
- Department of Medical Laboratory Science and Biotechnology, Asia University, Taichung, Taiwan, Republic of China
| | - Yi-Tsung Lin
- Division of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China
- Department of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, Republic of China
| | - Tsuey-Ching Yang
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, Republic of China
| | - Li-Hua Li
- Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China
- School of Medical Laboratory Science and Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan, Republic of China
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Chauviat A, Meyer T, Favre-Bonté S. Versatility of Stenotrophomonas maltophilia: Ecological roles of RND efflux pumps. Heliyon 2023; 9:e14639. [PMID: 37089375 PMCID: PMC10113797 DOI: 10.1016/j.heliyon.2023.e14639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/13/2023] [Accepted: 03/14/2023] [Indexed: 03/30/2023] Open
Abstract
S. maltophilia is a widely distributed bacterium found in natural, anthropized and clinical environments. The genome of this opportunistic pathogen of environmental origin includes a large number of genes encoding RND efflux pumps independently of the clinical or environmental origin of the strains. These pumps have been historically associated with the uptake of antibiotics and clinically relevant molecules because they confer resistance to many antibiotics. However, considering the environmental origin of S. maltophilia, the ecological role of these pumps needs to be clarified. RND efflux systems are highly conserved within bacteria and encountered both in pathogenic and non-pathogenic species. Moreover, their evolutionary origin, conservation and multiple copies in bacterial genomes suggest a primordial role in cellular functions and environmental adaptation. This review is aimed at elucidating the ecological role of S. maltophilia RND efflux pumps in the environmental context and providing an exhaustive description of the environmental niches of S. maltophilia. By looking at the substrates and functions of the pumps, we propose different involvements and roles according to the adaptation of the bacterium to various niches. We highlight that i°) regulatory mechanisms and inducer molecules help to understand the conditions leading to their expression, and ii°) association and functional redundancy of RND pumps and other efflux systems demonstrate their complex role within S. maltophilia cells. These observations emphasize that RND efflux pumps play a role in the versatility of S. maltophilia.
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Li LH, Wu CM, Chang CL, Huang HH, Wu CJ, Yang TC. σ P-NagA-L1/L2 Regulatory Circuit Involved in ΔompA299-356-Mediated Increase in β-Lactam Susceptibility in Stenotrophomonas maltophilia. Microbiol Spectr 2022; 10:e0279722. [PMID: 36350132 PMCID: PMC9769791 DOI: 10.1128/spectrum.02797-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 10/13/2022] [Indexed: 11/11/2022] Open
Abstract
OmpA, the most abundant porin in Stenotrophomonas maltophilia KJ, exists as a two-domain structure with an N-terminal domain of β-barrel structure embedded in the outer membrane and a C-terminal domain collocated in the periplasm. KJΔOmpA299-356, an ompA mutant of S. maltophilia KJ with a truncated OmpA devoid of 299 to 356 amino acids (aa), was able to stably embed in the outer membrane. KJΔOmpA299-356 was more susceptible to β-lactams than wild-type KJ. We aimed to elucidate the mechanism underlying the ΔompA299-356-mediated increase in β-lactam susceptibility (abbreviated as "ΔOmpA299-356 phenotype"). KJΔOmpA299-356 displayed a lower ceftazidime (CAZ)-induced β-lactamase activity than KJ. Furthermore, KJ2, a L1/L2 β-lactamases-null mutant, and KJ2ΔOmpA299-356, a KJ2 mutant with truncated OmpA devoid of299 to 356 aa, had comparable β-lactam susceptibility. Both lines of evidence indicate that decreased β-lactamase activity contributes to the ΔOmpA299-356 phenotype. We analyzed the transcriptome results of KJ and KJΔOmpA299-356, focusing on PG homeostasis-associated genes. Among the 36 genes analyzed, the nagA gene was upregulated 4.65-fold in KJΔOmpA299-356. Deletion of the nagA gene from the chromosome of KJΔOmpA299-356 restored β-lactam susceptibility and CAZ-induced β-lactamase activity to wild-type levels, verifying that nagA-upregulation in KJΔOmpA299-356 contributes to the ΔOmpA299-356 phenotype. Furthermore, transcriptome analysis revealed that rpoE (Smlt3555) and rpoP (Smlt3514) were significantly upregulated in KJΔOmpA299-356. The deletion mutant construction, β-lactam susceptibility, and β-lactamase activity analysis demonstrated that σP, but not σE, was involved in the ΔOmpA299-356 phenotype. A real-time quantitative (qRT-PCR) assay confirmed that nagA is a member of the σP regulon. The involvement of the σP-NagA-L1/L2 regulatory circuit in the ΔOmpA299-356 phenotype was manifested. IMPORTANCE Porins of Gram-negative bacteria generally act as channels that allow the entry or extrusion of molecules. Moreover, the structural role of porins in stabilizing the outer membrane by interacting with peptidoglycan (PG) and the outer membrane has been proposed. The linkage between porin deficiency and antibiotic resistance increase has been reported widely, with a rationale for blocking antibiotic influx. In this study, a link between porin defects and β-lactam susceptibility increase was demonstrated. The underlying mechanism revealed that a novel σP-NagA-L1/L2 regulatory circuit is triggered due to the loss of the OmpA-PG interaction. This study extends the understanding on the porin defect and antibiotic susceptibility. Porin defects may cause opposite impacts on antibiotic susceptibility, which is dependent on the involvement of the defect. Blocking the porin channel role can increase antibiotic resistance; in contrast, the loss of porin structure role may increase antibiotic susceptibility.
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Affiliation(s)
- Li-Hua Li
- Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- School of Medical Laboratory Science and Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Cheng-Mu Wu
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Chia-Lun Chang
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
- Department of Laboratory Medicine, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu, Taiwan
| | - Hsin-Hui Huang
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Chao-Jung Wu
- School of Medical Laboratory Science and Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Tsuey-Ching Yang
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
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The Contribution of Efflux Systems to Levofloxacin Resistance in Stenotrophomonas maltophilia Clinical Strains Isolated in Warsaw, Poland. BIOLOGY 2022; 11:biology11071044. [PMID: 36101423 PMCID: PMC9311822 DOI: 10.3390/biology11071044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/04/2022] [Accepted: 07/08/2022] [Indexed: 11/17/2022]
Abstract
Simple Summary Fluoroquinolones, mainly levofloxacin, are considered an alternative treatment option of Stenotrophomonas maltophilia infections to trimethoprim/sulfamethoxazole. However, an increase in the number of levofloxacin-resistant strains is observed worldwide. The fluoroquinolone resistance in S. maltophilia is usually caused by an overproduction of various multidrug efflux pumps, which are able to extrude antibiotics and chemotherapeutics from the bacterial cells. The purpose of the study was to analyze the contribution of efflux systems to levofloxacin resistance in S. maltophilia clinical strains, isolated in Warsaw, by phenotypic and molecular methods. Previously, the occurrence of genes encoding various ten efflux pumps was shown in 94 studied isolates. Additionally, 44 of 94 isolates demonstrated reduction in susceptibility to levofloxacin. In this study, in the presence of efflux pump inhibitors, an increase in levofloxacin susceptibility was observed in 13 isolates. The overexpression of genes encoding two efflux pump system, such as SmeDEF and Sme VWX (in five and one isolate, respectively), was demonstrated. Sequencing analysis revealed an amino acid change in the local regulators of these efflux pump operons. Our data indicate that the overproduction of the SmeVWX efflux system, unlike SmeDEF, plays a significant role in the levofloxacin resistance of the clinical isolates. Abstract Levofloxacin is considered an alternative treatment option of Stenotrophomonas maltophilia infections to trimethoprim/sulfamethoxazole. The fluoroquinolone resistance in S. maltophilia is usually caused by an overproduction of efflux pumps. In this study, the contribution of efflux systems to levofloxacin resistance in S. maltophilia clinical isolates was demonstrated using phenotypic (minimal inhibitory concentrations, MICs, of antibiotics determination ± efflux pump inhibitors, EPIs) and molecular (real-time polymerase-chain-reaction and sequencing) methods. Previously, the occurrence of genes encoding ten efflux pumps was shown in 94 studied isolates. Additionally, 44/94 isolates demonstrated reduction in susceptibility to levofloxacin. Only 5 of 13 isolates (with ≥4-fold reduction in levofloxacin MIC) in the presence of EPIs showed an increased susceptibility to levofloxacin and other antibiotics. The overexpression of smeD and smeV genes (in five and one isolate, respectively) of 5 tested efflux pump operons was demonstrated. Sequencing analysis revealed 20–35 nucleotide mutations in local regulatory genes such as smeT and smeRv. However, mutations leading to an amino acid change were shown only in smeT (Arg123Lys, Asp182Glu, Asp204Glu) for one isolate and in smeRv (Gly266Ser) for the other isolate. Our data indicate that the overproduction of the SmeVWX efflux system, unlike SmeDEF, plays a significant role in the levofloxacin resistance.
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Wu CJ, Chen Y, Li LH, Wu CM, Lin YT, Ma CH, Yang TC. Roles of SmeYZ, SbiAB, and SmeDEF Efflux Systems in Iron Homeostasis of Stenotrophomonas maltophilia. Microbiol Spectr 2022; 10:e0244821. [PMID: 35647692 PMCID: PMC9241820 DOI: 10.1128/spectrum.02448-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 04/30/2022] [Indexed: 11/28/2022] Open
Abstract
Stenotrophomonas maltophilia, a nonfermenting Gram-negative rod, is frequently isolated from the environment and is emerging as a multidrug-resistant global opportunistic pathogen. S. maltophilia harbors eight RND-type efflux pumps that contribute to multidrug resistance and physiological functions. Among the eight efflux pumps, SmeYZ pump is constitutively highly expressed. In our previous study, we demonstrated that loss-of-function of the SmeYZ pump results in pleiotropic phenotypes, including abolished swimming motility, decreased secreted protease activity, and compromised tolerance to oxidative stress and antibiotics. In this study, we attempted to elucidate the underlying mechanisms responsible for ΔsmeYZ-mediated pleiotropic phenotypes. RNA-seq transcriptome analysis and subsequent confirmation with qRT-PCR revealed that smeYZ mutant experienced an iron starvation response because the genes involved in the synthesis and uptake of stenobactin, the sole siderophore of S. maltophilia, were significantly upregulated. We further verified that smeYZ mutant had low intracellular iron levels via inductively coupled plasma mass spectrometry (ICP-MS). Also, KJΔYZ was more sensitive to 2,2'-dipyridyl (DIP), a ferrous iron chelator, in comparison with the wild type. The contribution of SmeYZ, SmeDEF, and SbiAB pumps to stenobactin secretion was suggested by qRT-PCR and further verified by Chrome Azurol S (CAS) activity, iron source utilization, and cell viability assays. We also demonstrated that loss-of-function of SmeYZ led to the compensatory upregulation of SbiAB and SmeDEF pumps for stenobactin secretion. The overexpression of the SbiAB pump resulted in a reduction in intracellular iron levels, which may be the key factor responsible for the ΔsmeYZ-mediated pleiotropic phenotypes, except for antibiotic extrusion. IMPORTANCE Efflux pumps display high efficiency of drug extrusion, which underlies their roles in multidrug resistance. In addition, efflux pumps have physiological functions, and their expression is tightly regulated by various environmental and physiological signals. Functional redundancy of efflux pumps is commonly observed, and mutual regulation occurs among these functionally redundant pumps in a bacterium. Stenotrophomonas maltophilia is an opportunistic pathogen that shows intrinsic multi-drug resistance. In this study, we demonstrated that SmeYZ, SbiAB, and SmeDEF efflux pumps of S. maltophilia display functional redundancy in siderophore secretion. Inactivation of smeYZ led to the upregulation of smeDEF and sbiAB. Unexpectedly, sbiAB overexpression resulted in the reduction of intracellular iron levels, which led to pleiotropic defects in smeYZ mutant. This study demonstrates a previously unidentified connection between efflux pumps, siderophore secretion, and intracellular iron levels in S. maltophilia.
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Affiliation(s)
- Chao-Jung Wu
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
- School of Medical Laboratory Science and Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Yu Chen
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Li-Hua Li
- School of Medical Laboratory Science and Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
- Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Cheng-Mu Wu
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yi-Tsung Lin
- Division of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Cheng-Hua Ma
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
| | - Tsuey-Ching Yang
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
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Mojica MF, Humphries R, Lipuma JJ, Mathers AJ, Rao GG, Shelburne SA, Fouts DE, Van Duin D, Bonomo RA. Clinical challenges treating Stenotrophomonas maltophilia infections: an update. JAC Antimicrob Resist 2022; 4:dlac040. [PMID: 35529051 PMCID: PMC9071536 DOI: 10.1093/jacamr/dlac040] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2023] Open
Abstract
Stenotrophomonas maltophilia is a non-fermenting, Gram-negative bacillus that has emerged as an opportunistic nosocomial pathogen. Its intrinsic multidrug resistance makes treating infections caused by S. maltophilia a great clinical challenge. Clinical management is further complicated by its molecular heterogeneity that is reflected in the uneven distribution of antibiotic resistance and virulence determinants among different strains, the shortcomings of available antimicrobial susceptibility tests and the lack of standardized breakpoints for the handful of antibiotics with in vitro activity against this microorganism. Herein, we provide an update on the most recent literature concerning these issues, emphasizing the impact they have on clinical management of S. maltophilia infections.
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Affiliation(s)
- Maria F. Mojica
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
- Case Western Reserve University-Cleveland VA Medical Center for Antimicrobial Resistance and Epidemiology (Case VA CARES), Cleveland, OH, USA
- Research Service, VA Northeast Ohio Healthcare System, Cleveland, OH, USA
- Grupo de Resistencia Antimicrobiana y Epidemiología Hospitalaria, Universidad El Bosque, Bogotá, Colombia
| | - Romney Humphries
- Department of Pathology, Immunology and Microbiology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - John J. Lipuma
- University of Michigan Medical School, Pediatric Infectious Disease, Ann Arbor, MI, USA
| | - Amy J. Mathers
- Division of Infectious Disease and International Health, Department of Medicine, University of Virginia Health System, Charlottesville, VA, USA
- Clinical Microbiology Laboratory, Department of Pathology, University of Virginia Health System, Charlottesville, VA, USA
| | - Gauri G. Rao
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Samuel A. Shelburne
- Department of Infectious Diseases Infection Control and Employee Health, University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of Genomic Medicine, University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center McGovern Medical School, Houston, TX, USA
| | - Derrick E. Fouts
- Genomic Medicine, The J. Craig Venter Institute, Rockville, MD, USA
| | - David Van Duin
- Department of Medicine, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Robert A. Bonomo
- Case Western Reserve University-Cleveland VA Medical Center for Antimicrobial Resistance and Epidemiology (Case VA CARES), Cleveland, OH, USA
- Research Service, VA Northeast Ohio Healthcare System, Cleveland, OH, USA
- Senior Clinician Scientist Investigator, Veterans Affairs Northeast Ohio Healthcare System, Cleveland, OH, USA
- Medical Service and Geriatric Research, Education, and Clinical Center (GRECC), Veterans Affairs Northeast Ohio Healthcare System, Cleveland, OH, USA
- Departments of Medicine, Biochemistry, Pharmacology, Molecular Biology and Microbiology, and Proteomics and Bioinformatics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
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Scoffone VC, Trespidi G, Barbieri G, Irudal S, Perrin E, Buroni S. Role of RND Efflux Pumps in Drug Resistance of Cystic Fibrosis Pathogens. Antibiotics (Basel) 2021; 10:863. [PMID: 34356783 PMCID: PMC8300704 DOI: 10.3390/antibiotics10070863] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/01/2021] [Accepted: 07/13/2021] [Indexed: 01/21/2023] Open
Abstract
Drug resistance represents a great concern among people with cystic fibrosis (CF), due to the recurrent and prolonged antibiotic therapy they should often undergo. Among Multi Drug Resistance (MDR) determinants, Resistance-Nodulation-cell Division (RND) efflux pumps have been reported as the main contributors, due to their ability to extrude a wide variety of molecules out of the bacterial cell. In this review, we summarize the principal RND efflux pump families described in CF pathogens, focusing on the main Gram-negative bacterial species (Pseudomonas aeruginosa, Burkholderia cenocepacia, Achromobacter xylosoxidans, Stenotrophomonas maltophilia) for which a predominant role of RND pumps has been associated to MDR phenotypes.
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Affiliation(s)
- Viola Camilla Scoffone
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, 27100 Pavia, Italy; (V.C.S.); (G.T.); (G.B.); (S.I.)
| | - Gabriele Trespidi
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, 27100 Pavia, Italy; (V.C.S.); (G.T.); (G.B.); (S.I.)
| | - Giulia Barbieri
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, 27100 Pavia, Italy; (V.C.S.); (G.T.); (G.B.); (S.I.)
| | - Samuele Irudal
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, 27100 Pavia, Italy; (V.C.S.); (G.T.); (G.B.); (S.I.)
| | - Elena Perrin
- Department of Biology, University of Florence, 50019 Sesto Fiorentino, Italy
| | - Silvia Buroni
- Department of Biology and Biotechnology “Lazzaro Spallanzani”, University of Pavia, 27100 Pavia, Italy; (V.C.S.); (G.T.); (G.B.); (S.I.)
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Lu HF, Tsai YC, Li LH, Lin YT, Yang TC. Role of AzoR, a LysR-type transcriptional regulator, in SmeVWX pump-mediated antibiotic resistance in Stenotrophomonas maltophilia. J Antimicrob Chemother 2021; 76:2285-2293. [PMID: 34151959 DOI: 10.1093/jac/dkab203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 05/24/2021] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The SmeVWX efflux pump of Stenotrophomonas maltophilia contributes to menadione (MD) tolerance and resistance to chloramphenicol, quinolones and tetracycline. The components of the SmeVWX efflux pump are encoded by a five-gene operon, smeU1VWU2X. We have previously demonstrated that the smeU1VWU2X operon is intrinsically unexpressed and inducibly expressed by MD via a SoxR- and SmeRv-involved regulatory circuit in S. maltophilia KJ. We also inferred that there should be other regulator(s) involved in MD-mediated smeU1VWU2X expression in addition to SoxR and SmeRv. OBJECTIVES To identify novel regulator(s) involved in the regulation of MD-mediated smeU1VWU2X expression and elucidate the regulatory circuit. METHODS A possible regulator candidate involved in the regulation of MD-mediated smeU1VWU2X expression was identified by a homologue search using the helix-turn-helix domain of SmeRv as a query. Gene expression was assessed using the promoter-xylE transcriptional fusion assay and quantitative RT-PCR. The impact of the regulator on SmeVWX pump-mediated functions was investigated via mutant construction and functional tests (antibiotic susceptibility and MD tolerance). RESULTS AzoR (Smlt3089), a LysR-type transcriptional regulator, was investigated. In unstressed logarithmically grown cells, AzoR was abundantly expressed and functioned as a repressor, inhibiting the expression of the smeU1VWU2X operon. MD challenge attenuated azoR expression, thus derepressing the expression of the smeU1VWU2X operon in S. maltophilia KJ. AzoR down-regulation-mediated smeU1VWU2X expression was observed in quinolone-resistant and SmeVWX-overexpressing S. maltophilia clinical isolates. CONCLUSIONS AzoR negatively regulates the expression of the smeU1VWU2X operon and SmeVWX pump-mediated antibiotic resistance in S. maltophilia.
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Affiliation(s)
- Hsu-Feng Lu
- Department of Clinical Pathology, Cheng Hsin General Hospital, Taipei, Taiwan.,Department of Medical Laboratory Science and Biotechnology, Asia University, Taichung, Taiwan
| | - Yu-Chieh Tsai
- Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei, Taiwan.,Division of Gastroenterology and Hepatology, Department of Internal Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Li-Hua Li
- Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.,PhD Program in Medical Biotechnology, Taipei Medical University, Taipei, Taiwan
| | - Yi-Tsung Lin
- Division of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.,School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Tsuey-Ching Yang
- Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei, Taiwan
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11
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Interplay between OmpA and RpoN Regulates Flagellar Synthesis in Stenotrophomonas maltophilia. Microorganisms 2021; 9:microorganisms9061216. [PMID: 34199787 PMCID: PMC8229486 DOI: 10.3390/microorganisms9061216] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/25/2021] [Accepted: 06/02/2021] [Indexed: 01/17/2023] Open
Abstract
OmpA, which encodes outer membrane protein A (OmpA), is the most abundant transcript in Stenotrophomonas maltophilia based on transcriptome analyses. The functions of OmpA, including adhesion, biofilm formation, drug resistance, and immune response targets, have been reported in some microorganisms, but few functions are known in S. maltophilia. This study aimed to elucidate the relationship between OmpA and swimming motility in S. maltophilia. KJΔOmpA, an ompA mutant, displayed compromised swimming and failure of conjugation-mediated plasmid transportation. The hierarchical organization of flagella synthesis genes in S. maltophilia was established by referencing the Pseudomonas aeruginosa model and was confirmed using mutant construction, qRT-PCR, and functional assays. Distinct from the P. aeruginosa model, rpoN, rather than fleQ and fliA, was at the top of the flagellar regulatory cascade in S. maltophilia. To elucidate the underlying mechanism responsible for ΔompA-mediated swimming compromise, transcriptome analysis of KJ and KJΔOmpA was performed and revealed rpoN downregulation in KJΔOmpA as the key element. The involvement of rpoN in ΔompA-mediated swimming compromise was verified using rpoN complementation, qRT-PCR, and function assays. Collectively, OmpA, which contributes to bacterial conjugation and swimming, is a promising target for adjuvant design in S. maltophilia.
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12
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Abstract
Stenotrophomonas maltophilia is an opportunistic pathogen of significant concern to susceptible patient populations. This pathogen can cause nosocomial and community-acquired respiratory and bloodstream infections and various other infections in humans. Sources include water, plant rhizospheres, animals, and foods. Studies of the genetic heterogeneity of S. maltophilia strains have identified several new genogroups and suggested adaptation of this pathogen to its habitats. The mechanisms used by S. maltophilia during pathogenesis continue to be uncovered and explored. S. maltophilia virulence factors include use of motility, biofilm formation, iron acquisition mechanisms, outer membrane components, protein secretion systems, extracellular enzymes, and antimicrobial resistance mechanisms. S. maltophilia is intrinsically drug resistant to an array of different antibiotics and uses a broad arsenal to protect itself against antimicrobials. Surveillance studies have recorded increases in drug resistance for S. maltophilia, prompting new strategies to be developed against this opportunist. The interactions of this environmental bacterium with other microorganisms are being elucidated. S. maltophilia and its products have applications in biotechnology, including agriculture, biocontrol, and bioremediation.
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13
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Menetrey Q, Sorlin P, Jumas-Bilak E, Chiron R, Dupont C, Marchandin H. Achromobacter xylosoxidans and Stenotrophomonas maltophilia: Emerging Pathogens Well-Armed for Life in the Cystic Fibrosis Patients' Lung. Genes (Basel) 2021; 12:610. [PMID: 33919046 PMCID: PMC8142972 DOI: 10.3390/genes12050610] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/06/2021] [Accepted: 04/19/2021] [Indexed: 02/07/2023] Open
Abstract
In patients with cystic fibrosis (CF), the lung is a remarkable ecological niche in which the microbiome is subjected to important selective pressures. An inexorable colonization by bacteria of both endogenous and environmental origin is observed in most patients, leading to a vicious cycle of infection-inflammation. In this context, long-term colonization together with competitive interactions among bacteria can lead to over-inflammation. While Pseudomonas aeruginosa and Staphylococcus aureus, the two pathogens most frequently identified in CF, have been largely studied for adaptation to the CF lung, in the last few years, there has been a growing interest in emerging pathogens of environmental origin, namely Achromobacter xylosoxidans and Stenotrophomonas maltophilia. The aim of this review is to gather all the current knowledge on the major pathophysiological traits, their supporting mechanisms, regulation and evolutionary modifications involved in colonization, virulence, and competitive interactions with other members of the lung microbiota for these emerging pathogens, with all these mechanisms being major drivers of persistence in the CF lung. Currently available research on A. xylosoxidans complex and S. maltophilia shows that these emerging pathogens share important pathophysiological features with well-known CF pathogens, making them important members of the complex bacterial community living in the CF lung.
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Affiliation(s)
- Quentin Menetrey
- HydroSciences Montpellier, CNRS, IRD, Univ Montpellier, 34093 Montpellier, France; (Q.M.); (P.S.)
| | - Pauline Sorlin
- HydroSciences Montpellier, CNRS, IRD, Univ Montpellier, 34093 Montpellier, France; (Q.M.); (P.S.)
| | - Estelle Jumas-Bilak
- HydroSciences Montpellier, CNRS, IRD, Univ Montpellier, Department d’Hygiène Hospitalière, CHU Montpellier, 34093 Montpellier, France; (E.J.-B.); (C.D.)
| | - Raphaël Chiron
- HydroSciences Montpellier, Université de Montpellier, CNRS, IRD, Centre de Ressources et de Compétences de la Mucoviscidose, CHU de Montpellier, 34093 Montpellier, France;
| | - Chloé Dupont
- HydroSciences Montpellier, CNRS, IRD, Univ Montpellier, Department d’Hygiène Hospitalière, CHU Montpellier, 34093 Montpellier, France; (E.J.-B.); (C.D.)
| | - Hélène Marchandin
- HydroSciences Montpellier, CNRS, IRD, Univ Montpellier, Service de Microbiologie et Hygiène Hospitalière, CHU Nîmes, 34093 Nîmes, France
- UMR 5151 HydroSciences Montpellier, Equipe Pathogènes Hydriques Santé Environnements, U.F.R. des Sciences Pharmaceutiques et Biologiques, Université de Montpellier, 15, Avenue Charles Flahault, BP 14491, CEDEX 5, 34093 Montpellier, France
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14
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Novel Mechanisms of Efflux-Mediated Levofloxacin Resistance and Reduced Amikacin Susceptibility in Stenotrophomonas maltophilia. Antimicrob Agents Chemother 2020; 65:AAC.01284-20. [PMID: 33139281 DOI: 10.1128/aac.01284-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 10/27/2020] [Indexed: 12/15/2022] Open
Abstract
Fluoroquinolone resistance in Stenotrophomonas maltophilia is multifactorial, but the most significant factor is overproduction of efflux pumps, particularly SmeDEF, following mutation. Here, we report that mutations in the glycosyl transferase gene smlt0622 in S. maltophilia K279a mutant K M6 cause constitutive activation of SmeDEF production, leading to elevated levofloxacin MIC. Selection of a levofloxacin-resistant K M6 derivative, K M6 LEVr, allowed identification of a novel two-component regulatory system, Smlt2645/6 (renamed SmaRS). The sensor kinase Smlt2646 (SmaS) is activated by mutation in K M6 LEVr causing overproduction of two novel ABC transporters and the known aminoglycoside efflux pump SmeYZ. Overproduction of one ABC transporter, Smlt1651-4 (renamed SmaCDEF), causes levofloxacin resistance in K M6 LEVr Overproduction of the other ABC transporter, Smlt2642/3 (renamed SmaAB), and SmeYZ both contribute to the elevated amikacin MIC against K M6 LEVr Accordingly, we have identified two novel ABC transporters associated with antimicrobial drug resistance in S. maltophilia and two novel regulatory systems whose mutation causes resistance to levofloxacin, clinically important as a promising drug for monotherapy against this highly resistant pathogen.
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15
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Gil-Gil T, Martínez JL, Blanco P. Mechanisms of antimicrobial resistance in Stenotrophomonas maltophilia: a review of current knowledge. Expert Rev Anti Infect Ther 2020; 18:335-347. [PMID: 32052662 DOI: 10.1080/14787210.2020.1730178] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Introduction: Stenotrophomonas maltophilia is a prototype of bacteria intrinsically resistant to antibiotics. The reduced susceptibility of this microorganism to antimicrobials mainly relies on the presence in its chromosome of genes encoding efflux pumps and antibiotic inactivating enzymes. Consequently, the therapeutic options for treating S. maltophilia infections are limited.Areas covered: Known mechanisms of intrinsic, acquired and phenotypic resistance to antibiotics of S. maltophilia and the consequences of such resistance for treating S. maltophilia infections are discussed. Acquisition of some genes, mainly those involved in co-trimoxazole resistance, contributes to acquired resistance. Mutation, mainly in the regulators of chromosomally-encoded antibiotic resistance genes, is a major cause for S. maltophilia acquisition of resistance. The expression of some of these genes is triggered by specific signals or stressors, which can lead to transient phenotypic resistance.Expert opinion: Treatment of S. maltophilia infections is difficult because this organism presents low susceptibility to antibiotics. Besides, it can acquire resistance to antimicrobials currently in use. Particularly problematic is the selection of mutants overexpressing efflux pumps since they present a multidrug resistance phenotype. The use of novel antimicrobials alone or in combination, together with the development of efflux pumps' inhibitors may help in fighting S. maltophilia infections.
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Affiliation(s)
| | | | - Paula Blanco
- Molecular Basis of Adaptation Laboratory, Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain
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