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Freeman CD, Hansen T, Urbauer R, Wilkinson BJ, Singh VK, Hines KM. Defective pgsA contributes to increased membrane fluidity and cell wall thickening in Staphylococcus aureus with high-level daptomycin resistance. mSphere 2024; 9:e0011524. [PMID: 38752757 DOI: 10.1128/msphere.00115-24] [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: 02/14/2024] [Accepted: 04/17/2024] [Indexed: 05/28/2024] Open
Abstract
Daptomycin is a membrane-targeting last-resort antimicrobial therapeutic for the treatment of infections caused by methicillin- and/or vancomycin-resistant Staphylococcus aureus. In the rare event of failed daptomycin therapy, the source of resistance is often attributable to mutations directly within the membrane phospholipid biosynthetic pathway of S. aureus or in the regulatory systems that control cell envelope response and membrane homeostasis. Here we describe the structural changes to the cell envelope in a daptomycin-resistant isolate of S. aureus strain N315 that has acquired mutations in the genes most commonly reported associated with daptomycin resistance: mprF, yycG, and pgsA. In addition to the decreased phosphatidylglycerol (PG) levels that are the hallmark of daptomycin resistance, the mutant with high-level daptomycin resistance had increased branched-chain fatty acids (BCFAs) in its membrane lipids, increased membrane fluidity, and increased cell wall thickness. However, the successful utilization of isotope-labeled straight-chain fatty acids (SCFAs) in lipid synthesis suggested that the aberrant BCFA:SCFA ratio arose from upstream alteration in fatty acid synthesis rather than a structural preference in PgsA. Transcriptomics studies revealed that expression of pyruvate dehydrogenase (pdhB) was suppressed in the daptomycin-resistant isolate, which is known to increase BCFA levels. While complementation with an additional copy of pdhB had no effect, complementation of the pgsA mutation resulted in increased PG formation, reduction in cell wall thickness, restoration of normal BCFA levels, and increased daptomycin susceptibility. Collectively, these results demonstrate that pgsA contributes to daptomycin resistance through its influence on membrane fluidity and cell wall thickness, in addition to phosphatidylglycerol levels. IMPORTANCE The cationic lipopeptide antimicrobial daptomycin has become an essential tool for combating infections with Staphylococcus aureus that display reduced susceptibility to β-lactams or vancomycin. Since daptomycin's activity is based on interaction with the negatively charged membrane of S. aureus, routes to daptomycin-resistance occur through mutations in the lipid biosynthetic pathway surrounding phosphatidylglycerols and the regulatory systems that control cell envelope homeostasis. Therefore, there are many avenues to achieve daptomycin resistance and several different, and sometimes contradictory, phenotypes of daptomycin-resistant S. aureus, including both increased and decreased cell wall thickness and membrane fluidity. This study is significant because it demonstrates the unexpected influence of a lipid biosynthesis gene, pgsA, on membrane fluidity and cell wall thickness in S. aureus with high-level daptomycin resistance.
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Affiliation(s)
| | - Tayte Hansen
- Department of Microbiology and Immunology, A.T. Still University of Health Sciences, Kirksville, Missouri, USA
| | - Ramona Urbauer
- Department of Chemistry, University of Georgia, Athens, Georgia, USA
| | - Brian J Wilkinson
- School of Biological Sciences, Illinois State University, Normal, Illinois, USA
| | - Vineet K Singh
- Department of Microbiology and Immunology, A.T. Still University of Health Sciences, Kirksville, Missouri, USA
| | - Kelly M Hines
- Department of Chemistry, University of Georgia, Athens, Georgia, USA
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2
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Zhu J, Xie R, Gao R, Zhao Y, Yodsanit N, Zhu M, Burger JC, Ye M, Tong Y, Gong S. Multimodal nanoimmunotherapy engages neutrophils to eliminate Staphylococcus aureus infections. NATURE NANOTECHNOLOGY 2024:10.1038/s41565-024-01648-8. [PMID: 38632494 DOI: 10.1038/s41565-024-01648-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 03/12/2024] [Indexed: 04/19/2024]
Abstract
The increasing prevalence of antimicrobial resistance in Staphylococcus aureus necessitates alternative therapeutic approaches. Neutrophils play a crucial role in the fight against S. aureus but suffer from deficiencies in function leading to increased infection. Here we report a nanoparticle-mediated immunotherapy aimed at potentiating neutrophils to eliminate S. aureus. The nanoparticles consist of naftifine, haemoglobin (Hb) and a red blood cell membrane coating. Naftifine disrupts staphyloxanthin biosynthesis, Hb reduces bacterial hydrogen sulfide levels and the red blood cell membrane modifies bacterial lipid composition. Collectively, the nanoparticles can sensitize S. aureus to host oxidant killing. Furthermore, in the infectious microenvironment, Hb triggers lipid peroxidation in S. aureus, promoting neutrophil chemotaxis. Oxygen supplied by Hb can also significantly enhance the bactericidal capability of the recruited neutrophils by restoring neutrophil respiratory burst via hypoxia relief. This multimodal nanoimmunotherapy demonstrates excellent therapeutic efficacy in treating antimicrobial-resistant S. aureus persisters, biofilms and S. aureus-induced infection in mice.
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Affiliation(s)
- Jingcheng Zhu
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, USA
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Ruosen Xie
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, USA
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Ruixuan Gao
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, USA
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Yi Zhao
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, USA
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Nisakorn Yodsanit
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, USA
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Min Zhu
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, USA
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Jacobus C Burger
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, USA
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Mingzhou Ye
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, USA
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Yao Tong
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, USA
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - Shaoqin Gong
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA.
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI, USA.
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA.
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, Wisconsin, USA.
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA.
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, USA.
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3
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Millette G, Lacasse E, Binette R, Belley V, Chaumont LP, Ster C, Beaudry F, Boyapelly K, Boudreault PL, Malouin F. Rationally Designed Pyrimidine Compounds: Promising Novel Antibiotics for the Treatment of Staphylococcus aureus-Associated Bovine Mastitis. Antibiotics (Basel) 2023; 12:1344. [PMID: 37627764 PMCID: PMC10451377 DOI: 10.3390/antibiotics12081344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/18/2023] [Accepted: 08/19/2023] [Indexed: 08/27/2023] Open
Abstract
Staphylococcus aureus is one of the major pathogens causing bovine mastitis, and antibiotic treatment is most often inefficient due to its virulence and antibiotic-resistance attributes. The development of new antibiotics for veterinary use should account for the One Health concept, in which humans, animals, and environmental wellbeing are all interconnected. S. aureus can infect cattle and humans alike and antibiotic resistance can impact both if the same classes of antibiotics are used. New effective antibiotic classes against S. aureus are thus needed in dairy farms. We previously described PC1 as a novel antibiotic, which binds the S. aureus guanine riboswitch and interrupts transcription of essential GMP synthesis genes. However, chemical instability of PC1 hindered its development, evaluation, and commercialization. Novel PC1 analogs with improved stability have now been rationally designed and synthesized, and their in vitro and in vivo activities have been evaluated. One of these novel compounds, PC206, remains stable in solution and demonstrates specific narrow-spectrum activity against S. aureus. It is active against biofilm-embedded S. aureus, its cytotoxicity profile is adequate, and in vivo tests in mice and cows show that it is effective and well tolerated. PC206 and structural analogs represent a promising new antibiotic class to treat S. aureus-induced bovine mastitis.
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Affiliation(s)
- Guillaume Millette
- Department of Biology, Institute of Sciences, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (G.M.); (E.L.); (C.S.)
| | - Evelyne Lacasse
- Department of Biology, Institute of Sciences, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (G.M.); (E.L.); (C.S.)
| | - Renaud Binette
- Department of Chemistry, Institute of Sciences, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada;
| | - Véronique Belley
- Department of Biology, Institute of Sciences, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (G.M.); (E.L.); (C.S.)
| | - Louis-Philippe Chaumont
- Department of Biology, Institute of Sciences, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (G.M.); (E.L.); (C.S.)
| | - Céline Ster
- Department of Biology, Institute of Sciences, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (G.M.); (E.L.); (C.S.)
| | - Francis Beaudry
- Department of Veterinary Biomedicine, Institute of Veterinary Medicine, University of Montreal, St-Hyacinthe, QC J2S 2M2, Canada;
| | - Kumaraswamy Boyapelly
- Department of Pharmacology and Physiology, Institute of Medicine and Health Sciences, Sherbrooke University, Sherbrooke, QC J1H 5N4, Canada
| | - Pierre-Luc Boudreault
- Department of Pharmacology and Physiology, Institute of Medicine and Health Sciences, Sherbrooke University, Sherbrooke, QC J1H 5N4, Canada
| | - François Malouin
- Department of Biology, Institute of Sciences, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (G.M.); (E.L.); (C.S.)
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Kikukawa H, Nagao T, Ota M, Takashima S, Kitaguchi K, Yanase E, Maeda S, Hara KY. Production of a selective antibacterial fatty acid against Staphylococcus aureus by Bifidobacterium strains. MICROBIOME RESEARCH REPORTS 2023; 2:4. [PMID: 38045611 PMCID: PMC10688799 DOI: 10.20517/mrr.2022.24] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/06/2023] [Accepted: 02/10/2023] [Indexed: 12/05/2023]
Abstract
Aims: C16 monounsaturated fatty acid (C16:1) show antibacterial activity against Staphylococcus aureus, a pathogen associated with various diseases such as atopic dermatitis and bacteremia, while the compound does not exhibit antibacterial activity against Staphylococcus epidermidis, an epidermal commensal that inhibits the growth of S. aureus. In this study, we aimed to find bifidobacterial strains with the ability to produce C16:1 and to find a practical manner to utilize C16:1-producing strains in industry. Methods: Various Bifidobacterium strains were screened for their content of C16:1. The chemical identity of C16:1 produced by a selected strain was analyzed by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). Medium components that affect the C16:1 content of the selected strain were investigated. Antibacterial activity against staphylococci was compared between the authentic C16:1 isomers and total fatty acids (TFA) extracted from the selected strain. Results: B. adolescentis 12451, B. adolescentis 12-111, B. boum JCM 1211, and Bifidobacterium sp. JCM 7042 showed high C16:1 content among the tested strains. TFA extracted from Bifidobacterium sp. JCM 7042 contained C16:1 at 2.3% as the fatty acid constituent (2.4 mg/L of broth). Through GC-MS and LC-MS analyses, the C16:1 synthesized by Bifidobacterium sp. JCM 7042 was identified as 7-cis-hexadecenoic acid (7-cis-C16:1). The authentic 7-cis-C16:1 showed strong and selective antibacterial activity against S. aureus, similar to 6-cis-C16:1, with a minimum inhibitory concentration (MIC) of < 10 µg/mL. Components that increase C16:1 productivity were not found in the MRS and TOS media; however, Tween 80 was shown to considerably reduce the C16:1 ratio in TFA. Antibacterial activity against S. aureus was observed when the TFA extracted from Bifidobacterium sp. JCM 7042 contained high level of 7-cis-C16:1 (6.1% in TFA) but not when it contained low level of 7-cis-C16:1 (0.1% in TFA). Conclusion: The fatty acid, 7-cis-C16:1, which can selectively inhibit the S. aureus growth, is accumulated in TFA of several bifidobacteria. The TFA extracted from cultured cells of Bifidobacterium sp. JCM 7042 demonstrated antibacterial activity. From a practical viewpoint, our findings are important for developing an efficient method to produce novel skin care cosmetics, functional dairy foods, and other commodities.
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Affiliation(s)
- Hiroshi Kikukawa
- Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
- School of Food and Nutritional Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
| | - Toshihiro Nagao
- Research Division of Biomaterials and Commodity Chemicals, Osaka Research Institute of Industrial Science and Technology, Osaka 536-8553, Japan
| | - Mitsuki Ota
- Graduate School of Natural Science and Technology, Gifu University, Gifu 501-1193, Japan
| | - Shigeo Takashima
- Institute for Glyco-core Research (iGCORE), Gifu University, Gifu 501-1193, Japan
| | - Kohji Kitaguchi
- Faculty of Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan
| | - Emiko Yanase
- Faculty of Applied Biological Sciences, Gifu University, Gifu 501-1193, Japan
| | - Sadatoshi Maeda
- The United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
| | - Kiyotaka Y. Hara
- Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
- School of Food and Nutritional Sciences, University of Shizuoka, Shizuoka 422-8526, Japan
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5
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Poshvina DV, Dilbaryan DS, Kasyanov SP, Sadykova VS, Lapchinskaya OA, Rogozhin EA, Vasilchenko AS. Staphylococcus aureus is able to generate resistance to novel lipoglycopeptide antibiotic gausemycin A. Front Microbiol 2022; 13:963979. [PMID: 36246291 PMCID: PMC9558223 DOI: 10.3389/fmicb.2022.963979] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 09/14/2022] [Indexed: 11/13/2022] Open
Abstract
Gausemycin A is the first member of the novel lipoglycopeptides family produced by Streptomyces roseoflavus INA-Ac-5812. Gausemycin A has a pronounced bactericidal activity against methicillin-resistant Staphylococcus aureus. However, the ability of S. aureus to be resistant to gausemycin A has not been investigated yet. Using serial passaging, we have obtained the resistant variant S. aureus 5812R, which is 80 times more resistant compared to the parent strain. Susceptibility testing of S. aureus 5812R revealed the acquisition of cross-resistance to daptomycin, cefazolin, tetracycline, and gentamicin, while the resistance to vancomycin, nisin, and ramoplanin was absent. Whole genome sequencing revealed single nucleotide polymorphism (SNP) and deletions in S. aureus 5812R, among which are genes encoding efflux pump (sepA), the two-component Kdp system (kdpE), and the component of isoprenoid biosynthesis pathway (hepT). Phenotypically, S. aureus 5812R resembles a small-colony variant, as it is slow-growing, forms small colonies, and is deficient in pigments. Profiling of fatty acids (FA) composition constituting the cytoplasmic membrane of S. aureus 5812R revealed the prevalence of anteiso-branched FA, while straight FA was slightly less present. The evidence also showed that the gausemycin A-resistant strain has increased expression of the cls2 gene of the cardiolipin synthase. The performed checkerboard assay pointed out that the combination of gausemycin A and ciprofloxacin showed a synergistic effect against S. aureus 5812R.
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Affiliation(s)
- Darya V. Poshvina
- Laboratory of Antimicrobial Resistance, Institute of Environmental and Agricultural Biology (X-BIO), Tyumen State University, Tyumen, Russia
| | - Diana S. Dilbaryan
- Laboratory of Antimicrobial Resistance, Institute of Environmental and Agricultural Biology (X-BIO), Tyumen State University, Tyumen, Russia
| | - Sergey P. Kasyanov
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Vladivostok, Russia
| | | | | | - Eugene A. Rogozhin
- Gause Institute of New Antibiotics, Moscow, Russia
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences, Moscow, Russia
| | - Alexey S. Vasilchenko
- Laboratory of Antimicrobial Resistance, Institute of Environmental and Agricultural Biology (X-BIO), Tyumen State University, Tyumen, Russia
- *Correspondence: Alexey S. Vasilchenko
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The Role of Methyl-(Z)-11-tetradecenoate Acid from the Bacterial Membrane Lipid Composition in Escherichia coli Antibiotic Resistance. BIOMED RESEARCH INTERNATIONAL 2022; 2022:6028045. [PMID: 35734346 PMCID: PMC9209004 DOI: 10.1155/2022/6028045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 05/10/2022] [Accepted: 05/14/2022] [Indexed: 11/18/2022]
Abstract
Background The bacterial membrane plays a critical role in the survival of bacteria and the effectiveness of antimicrobial peptides in protecting the host. The lipid constituents of the bacterial membrane are not evenly distributed, and they could be affected by clustering anionic lipids with cationic peptides with multiple positive charges. That could be harmful to bacteria because it prevents lipids from interacting with other molecular components of the cell membrane, disrupts existing natural domains, or creates phase boundary defects between the clustered lipids and the bulk of the membrane. This preliminary quantitative study is aimed at assembling a correlation between antibiotic resistance and bacterial lipid composition in E. coli, based on the function and arrangement of the bilipid coating of the bacterial cell, intimately associated with the path of antimicrobials through membranes. Methods Fifteen multiresistant E. coli samples are collected from swine with enterocolitis tested for resistance levels using the disc diffusimetric method (Kirby-Bauer disc diffusion). Pathogen identification completed using the API 20E multitest system revealed the E. coli presence in 11 samples. In these samples, bacterial membrane detection of fatty acid methyl esters (FAME) operating a 240 MS Ion Trap (Varian) GC/MS (Agilent Technologies, Santa Clara, CA, USA) was performed, using the MIDI Sherlock recognition software model. Results Interpreting the descriptive statistical method, the correlation matrix, and regression curves and after ANOVA analysis, we ascertained that the studied E. coli population statistically confirmed different degrees of resistance in most of the samples analyzed in this test. Conclusions In one case, the methyl-(Z)-11-tetradecenoate acid was observed to have a relationship with the susceptibility evaluation by using the disc diffusimetric method, which has revealed the lowest rate of antimicrobial resistance, so it has importance in further resistance evaluation studies.
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Guzek A, Rybicki Z, Woźniak-Kosek A, Tomaszewski D. Bloodstream Infections in the Intensive Care Unit: a Single-Center Retrospective Bacteriological Analysis Between 2007 and 2019. Pol J Microbiol 2022; 71:263-277. [PMID: 35716169 PMCID: PMC9252137 DOI: 10.33073/pjm-2022-025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 05/14/2022] [Indexed: 11/05/2022] Open
Abstract
Hospital-acquired bloodstream infections are a severe worldwide problem associated with significant morbidity and mortality. This retrospective, single-center study aimed to analyze bloodstream infections in patients hospitalized in the intensive care unit of the Military Institute of Medicine, Poland. Data from the years 2007-2019 were analyzed. When the infection was suspected, blood samples were drawn and analyzed microbiologically. When bacterial growth was observed, an antimicrobial susceptibility/resistance analysis was performed. Among 12,619 analyzed samples, 1,509 were positive, and 1,557 pathogens were isolated. In 278/1,509 of the positive cases, a central line catheter infection was confirmed. Gram-negative bacteria were the most frequently (770/1,557) isolated, including Acinetobacter baumannii (312/770), Klebsiella pneumoniae (165/770; 67/165 were the isolates that expressed extended spectrum beta-lactamases (ESBL), 5/165 isolates produced the New Delhi metallo-β-lactamases (NDM), 4/165 isolates expressed Klebsiella pneumoniae carbapenemase (KPC), and 1/165 isolate produced OXA48 carbapenemase), Pseudomonas aeruginosa (111/770; 2/111 isolates produced metallo-β-lactamase (MBL), and Escherichia coli (69/770; 11/69 - ESBL). Most Gram-positive pathogens were staphylococci (545/733), mainly coagulase-negative (368/545). Among 545 isolates of the staphylococci, 58 represented methicillin-resistant Staphylococcus aureus (MRSA). Fungi were isolated from 3.5% of samples. All isolated MRSA and methicillin-resistant coagulase-negative Staphylococcus (MRCNS) strains were susceptible to vancomycin, methicillin-sensitive Staphylococcus aureus (MSSA) isolates - to isoxazolyl penicillins, and vancomycin-resistant Enterococcus (VRE) - to linezolid and tigecycline. However, colistin was the only therapeutic option in some infections caused by A. baumannii and KPC-producing K. pneumoniae. P. aeruginosa was still susceptible to cefepime and ceftazidime. Echinocandins were effective therapeutics in the treatment of fungal infections.
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Affiliation(s)
- Aneta Guzek
- Department of Laboratory Diagnostics, Section of Microbiology, Military Institute of Medicine, Warsaw, Poland
| | - Zbigniew Rybicki
- Department of Anesthesiology and Intensive Therapy, Military Institute of Medicine, Warsaw, Poland
| | | | - Dariusz Tomaszewski
- Department of Anesthesiology and Intensive Therapy, Military Institute of Aviation Medicine, Warsaw, Poland
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Okukawa M, Yoshizaki Y, Yano S, Nonomura Y. The Selective Antibacterial Activity of the Mixed Systems Containing Myristic Acid against Staphylococci. J Oleo Sci 2021; 70:1239-1246. [PMID: 34373405 DOI: 10.5650/jos.ess21090] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Fatty acids and their derivatives are interesting cosmetic ingredients because they show the selective antibacterial activity against Staphylococcus aureus (S. aureus). However, the antibacterial activity in mixed systems containing several active ingredients is unclear because previous studies focused antibacterial systems containing one kind of fatty acid. In the present study, the minimal inhibitory concentration (MIC) and the fractional inhibitory concentration (FIC) were evaluated for myristic acid/lauric acid, myristic acid/palmitoleic acid, and myristic acid/lactic acid mixed systems to show the effect of the coexisting components on the selective antibacterial activity of myristic acid. In the myristic acid/palmitoleic acid mixed system, the antibacterial activity against S. aureus was enhanced by additive effect, whereas the antibacterial activity was not observed against S. epidermidis. On the other hand, the myristic acid/lauric acid mixed system showed antibacterial activity against S. epidermidis: Lauric acid impaired the selectivity of antibacterial activity of myristic acid. These results suggest that the selective activity of myristic acid varies with the additives. The present findings are useful for designing formulations of cosmetics and body cleansers containing myristic acid.
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Affiliation(s)
- Minako Okukawa
- Department of Biochemical Engineering, Graduate School of Science and Engineering, Yamagata University
| | - Yuika Yoshizaki
- Department of Biochemical Engineering, Graduate School of Science and Engineering, Yamagata University
| | - Shigekazu Yano
- Department of Biochemical Engineering, Graduate School of Science and Engineering, Yamagata University
| | - Yoshimune Nonomura
- Department of Biochemical Engineering, Graduate School of Science and Engineering, Yamagata University
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Chinnappan M, Harris-Tryon TA. Novel mechanisms of microbial crosstalk with skin innate immunity. Exp Dermatol 2021; 30:1484-1495. [PMID: 34252227 DOI: 10.1111/exd.14429] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 06/28/2021] [Accepted: 07/06/2021] [Indexed: 12/12/2022]
Abstract
Skin is an organ with a dynamic ecosystem that harbours pathogenic and commensal microbes, which constantly communicate amongst each other and with the host immune system. Evolutionarily, skin and its microbiota have evolved to remain in homeostasis. However, frequently this homeostatic relationship is disturbed by a variety of factors such as environmental stress, diet, genetic mutations, and the microbiome itself. Commensal microbes also play a major role in the maintenance of microbial homeostasis. In addition to their ability to limit pathogens, many skin commensals such as Staphylococcus epidermidis and Cutibacterium acnes have recently been implicated in disease pathogenesis either by directly modulating the host immune components or by supporting the expansion of other pathogenic microbes. Likewise, opportunistic skin pathogens such as Staphylococcus aureus and Staphylococcus lugdunensis are able to breach the skin and cause disease. Though much has been established about the microbiota's function in skin immunity, we are in a time where newer mechanistic insights rapidly redefine our understanding of the host/microbial interface in the skin. In this review, we provide a concise summary of recent advances in our understanding of the interplay between host defense strategies and the skin microbiota.
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Affiliation(s)
- Mahendran Chinnappan
- Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Tamia A Harris-Tryon
- Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX, USA
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Abstract
Rhodomyrtone (Rom) is a plant-derived broad-spectrum antibiotic active against many Gram-positive pathogens. A single point mutation in the regulatory farR gene (farR*) confers resistance to Rom in Staphylococcus aureus (RomR). The mutation in farR* alters the activity of the regulator, FarR*, in such a way that not only its own gene, farR*, but also the divergently transcribed farE gene and genes controlled by the global regulator, agr, are highly upregulated. Here, we show that mainly the upregulation of the fatty acid efflux pump FarE causes the RomR phenotype, as farE deletion in either the parent or the RomR strain (RomR ΔfarE) yielded hypersensitivity to Rom. Comparative lipidome analysis of the supernatant (exolipidomics) and the pellet fraction revealed that the RomR strain excreted about 10 times more phospholipids (PGs) than the parent strain or the ΔfarE mutants. Since the PG content in the supernatant (2,244 ng/optical density [OD]) was more than 100-fold higher than that of fatty acids (FA), we assumed that PG interacts with Rom, thereby abrogating its antimicrobial activity. Indeed, by static and dynamic light scattering (SLS and DLS) and isothermal titration calorimetry (ITC) analyses, we could demonstrate that both PG and Rom were vesicular and reacted with each other in milliseconds to form a 1:1.49 [Rom-PG(32:0), where PG(32:0) is PG with C32:0 lipids] complex. The binding is entropically driven and hence hydrophobic and of low specificity in nature. Our results indicate that the cytoplasmic membrane is the actual target of Rom, which is also in agreement with Rom's induced rapid collapse of the membrane potential and decreased membrane integrity. IMPORTANCE Antibiotic resistance is a growing public health problem, and alternative antibiotics are urgently needed. Rhodomyrtone (Rom), an antimicrobial compound originally isolated from Rhodomyrtus tomentosa, is active against multidrug-resistant Gram-positive pathogens. However, Rom-resistant (RomR) mutants occur with low frequency. In this study, we unraveled the underlying resistance mechanism, which is based on a point mutation in the farR regulator gene, causing overexpression of FarE, which most likely acts as a phospholipid (PG) efflux pump, as large amounts of PG were found in the supernatant and the pellet fraction. We show that PG can bind to Rom, thereby abrogating its antimicrobial activity. The direct interaction of Rom with PG suggests that Rom's actual target is the cytoplasmic membrane. Antibiotics that interact with PG are rare. Since Rom can be chemically synthesized, it serves as a lead compound for synthesis of improved variants.
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Grafskaia E, Pavlova E, Babenko VV, Latsis I, Malakhova M, Lavrenova V, Bashkirov P, Belousov D, Klinov D, Lazarev V. The Hirudo Medicinalis Microbiome Is a Source of New Antimicrobial Peptides. Int J Mol Sci 2020; 21:E7141. [PMID: 32992666 PMCID: PMC7582656 DOI: 10.3390/ijms21197141] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 09/24/2020] [Accepted: 09/25/2020] [Indexed: 12/23/2022] Open
Abstract
Antimicrobial peptides (AMPs) are considered a promising new class of anti-infectious agents. This study reports new antimicrobial peptides derived from the Hirudo medicinalis microbiome identified by a computational analysis method applied to the H. medicinalis metagenome. The identified AMPs possess a strong antimicrobial activity against Gram-positive and Gram-negative bacteria (MIC range: 5.3 to 22.4 μM), including Staphylococcus haemolyticus, an opportunistic coagulase-negative pathogen. The secondary structure analysis of peptides via CD spectroscopy showed that all the AMPs except pept_352 have mostly disordered structures that do not change under different conditions. For peptide pept_352, the α-helical content increases in the membrane environment. The examination of the mechanism of action of peptides suggests that peptide pept_352 exhibits a direct membranolytic activity. Furthermore, the cytotoxicity assay demonstrated that the nontoxic peptide pept_1545 is a promising candidate for drug development. Overall, the analysis method implemented in the study may serve as an effective tool for the identification of new AMPs.
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Affiliation(s)
- Ekaterina Grafskaia
- Federal Research and Clinical Center of Physical Chemical Medicine of Federal Medical Biological Agency, Moscow 119435, Russia; (E.P.); (V.V.B.); (I.L.); (M.M.); (V.L.); (P.B.); (D.K.)
| | - Elizaveta Pavlova
- Federal Research and Clinical Center of Physical Chemical Medicine of Federal Medical Biological Agency, Moscow 119435, Russia; (E.P.); (V.V.B.); (I.L.); (M.M.); (V.L.); (P.B.); (D.K.)
- Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Moscow 141701, Russia
| | - Vladislav V. Babenko
- Federal Research and Clinical Center of Physical Chemical Medicine of Federal Medical Biological Agency, Moscow 119435, Russia; (E.P.); (V.V.B.); (I.L.); (M.M.); (V.L.); (P.B.); (D.K.)
| | - Ivan Latsis
- Federal Research and Clinical Center of Physical Chemical Medicine of Federal Medical Biological Agency, Moscow 119435, Russia; (E.P.); (V.V.B.); (I.L.); (M.M.); (V.L.); (P.B.); (D.K.)
| | - Maja Malakhova
- Federal Research and Clinical Center of Physical Chemical Medicine of Federal Medical Biological Agency, Moscow 119435, Russia; (E.P.); (V.V.B.); (I.L.); (M.M.); (V.L.); (P.B.); (D.K.)
| | - Victoria Lavrenova
- Federal Research and Clinical Center of Physical Chemical Medicine of Federal Medical Biological Agency, Moscow 119435, Russia; (E.P.); (V.V.B.); (I.L.); (M.M.); (V.L.); (P.B.); (D.K.)
- Department of biochemistry, Faculty of Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Pavel Bashkirov
- Federal Research and Clinical Center of Physical Chemical Medicine of Federal Medical Biological Agency, Moscow 119435, Russia; (E.P.); (V.V.B.); (I.L.); (M.M.); (V.L.); (P.B.); (D.K.)
| | - Dmitrii Belousov
- Sechenov First Moscow State Medical University Sechenov University, Moscow 119991, Russia;
| | - Dmitry Klinov
- Federal Research and Clinical Center of Physical Chemical Medicine of Federal Medical Biological Agency, Moscow 119435, Russia; (E.P.); (V.V.B.); (I.L.); (M.M.); (V.L.); (P.B.); (D.K.)
| | - Vassili Lazarev
- Federal Research and Clinical Center of Physical Chemical Medicine of Federal Medical Biological Agency, Moscow 119435, Russia; (E.P.); (V.V.B.); (I.L.); (M.M.); (V.L.); (P.B.); (D.K.)
- Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Moscow 141701, Russia
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Jenkins CL, Bean HD. Dependence of the Staphylococcal Volatilome Composition on Microbial Nutrition. Metabolites 2020; 10:metabo10090347. [PMID: 32867100 PMCID: PMC7569959 DOI: 10.3390/metabo10090347] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/16/2020] [Accepted: 08/23/2020] [Indexed: 01/09/2023] Open
Abstract
In vitro cultivation of staphylococci is fundamental to both clinical and research microbiology, but few studies, to-date, have investigated how the differences in rich media can influence the volatilome of cultivated bacteria. The objective of this study was to determine the influence of rich media composition on the chemical characteristics of the volatilomes of Staphylococcus aureus and Staphylococcus epidermidis. S. aureus (ATCC 12600) and S. epidermidis (ATCC 12228) were cultured in triplicate in four rich complex media (brain heart infusion (BHI), lysogeny broth (LB), Mueller Hinton broth (MHB), and tryptic soy broth (TSB)), and the volatile metabolites produced by each culture were analyzed using headspace solid-phase microextraction combined with comprehensive two-dimensional gas chromatography—time-of-flight mass spectrometry (HS-SPME-GC×GC-TOFMS). When comparing the chemical compositions of the staph volatilomes by the presence versus absence of volatiles produced in each medium, we observed few differences. However, when the relative abundances of volatiles were included in the analyses, we observed that culturing staph in media containing free glucose (BHI and TSB) resulted in volatilomes dominated by acids and esters (67%). The low-glucose media (LB and MHB) produced ketones in greatest relative abundances, but the volatilome compositions in these two media were highly dissimilar. We conclude that the staphylococcal volatilome is strongly influenced by the nutritional composition of the growth medium, especially the availability of free glucose, which is much more evident when the relative abundances of the volatiles are analyzed, compared to the presence versus absence.
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Affiliation(s)
- Carrie L. Jenkins
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA;
- Center for Fundamental and Applied Microbiomics, The Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA
| | - Heather D. Bean
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA;
- Center for Fundamental and Applied Microbiomics, The Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA
- Correspondence:
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