1
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Singh V, Nandanwar H. IMT-P8 potentiates Gram-positive specific antibiotics in intrinsically resistant Gram-negative bacteria. Antimicrob Agents Chemother 2024:e0075324. [PMID: 39235250 DOI: 10.1128/aac.00753-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Accepted: 08/06/2024] [Indexed: 09/06/2024] Open
Abstract
Gram-negative bacteria (GNB) pose a major global public health challenge as they exhibit a remarkable level of resistance to antibiotics. One of the factors responsible for promoting resistance against a wide range of antibiotics is the outer membrane (OM) of Gram-negative bacteria. The OM acts as a barrier that prevents the entry of numerous antibiotics by reducing their influx (due to membrane impermeability) and enhancing their efflux (with the help of efflux pumps). Our study focuses on analyzing the effect of IMT-P8, a cell-penetrating peptide (CPP), to enhance the influx of various Gram-positive specific antibiotics in multi-drug resistant Gram-negative pathogens. In the mechanistic experiments, IMT-P8 permeabilizes the OM at the same concentrations at which it enhances the activity of various antibiotics against GNB. Cytoplasmic membrane permeabilization was also observed at these concentrations, indicating that IMT-P8 acts on both the outer and cytoplasmic membranes. IMT-P8 interferes with the intrinsic resistance mechanism of GNB and has the potential to make Gram-positive specific antibiotics effective against GNB. IMT-P8 extends the post-antibiotic effect and in combination with antibiotics shows anti-persister activity. The IMT-P8/fusidic acid combination is effective in eliminating intracellular pathogens. IMT-P8 with negligible toxicity displayed good efficacy in murine lung and thigh infection models. Based on these findings, IMT-P8 is a potential antibiotic adjuvant to treat Gram-negative bacterial infections that pose a health hazard.
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Affiliation(s)
- Vidhu Singh
- Clinical Microbiology & Antimicrobial Research Laboratory, CSIR-Institute of Microbial Technology, Chandigarh, India
| | - Hemraj Nandanwar
- Clinical Microbiology & Antimicrobial Research Laboratory, CSIR-Institute of Microbial Technology, Chandigarh, India
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2
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Zelmer AR, Yang D, Gunn NJ, Solomon LB, Nelson R, Kidd SP, Richter K, Atkins GJ. Osteomyelitis-relevant antibiotics at clinical concentrations show limited effectivity against acute and chronic intracellular S. aureus infections in osteocytes. Antimicrob Agents Chemother 2024:e0080824. [PMID: 39194210 DOI: 10.1128/aac.00808-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2024] [Accepted: 08/09/2024] [Indexed: 08/29/2024] Open
Abstract
Osteomyelitis caused by Staphylococcus aureus can involve the persistent infection of osteocytes. We sought to determine if current clinically utilized antibiotics were capable of clearing an intracellular osteocyte S. aureus infection. Rifampicin, vancomycin, levofloxacin, ofloxacin, amoxicillin, oxacillin, doxycycline, linezolid, gentamicin, and tigecycline were assessed for their minimum inhibitory concentration (MIC) and minimum bactericidal concentrations against 12 S. aureus strains, at pH 5.0 and 7.2 to mimic lysosomal and cytoplasmic environments, respectively. Those antibiotics whose bone estimated achievable concentration was commonly above their respective MIC for the strains tested were further assayed in a human osteocyte infection model under acute and chronic conditions. Osteocyte-like cells were treated at 1×, 4×, and 10× the MIC for 1 and 7 days following infection (acute model), or at 15 and 21 days of infection (chronic model). The intracellular effectivity of each antibiotic was measured in terms of CFU reduction, small colony variant formation, and bacterial mRNA expression change. Only rifampicin, levofloxacin, and linezolid reduced intracellular CFU numbers significantly in the acute model. Consistent with the transition to a non-culturable state, few if any CFU could be recovered from the chronic model. However, no treatment in either model reduced the quantity of bacterial mRNA or prevented non-culturable bacteria from returning to a culturable state. These findings indicate that S. aureus adapts phenotypically during intracellular infection of osteocytes, adopting a reversible quiescent state that is protected against antibiotics, even at 10× their MIC. Thus, new therapeutic approaches are necessary to cure S. aureus intracellular infections in osteomyelitis.
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Affiliation(s)
- Anja R Zelmer
- Center for Orthopedic and Trauma Research, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, Australia
| | - Dongqing Yang
- Center for Orthopedic and Trauma Research, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, Australia
| | - Nicholas J Gunn
- Center for Orthopedic and Trauma Research, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, Australia
| | - L Bogdan Solomon
- Center for Orthopedic and Trauma Research, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, Australia
- Department of Orthopedics and Trauma, Royal Adelaide Hospital, Adelaide, Australia
| | - Renjy Nelson
- Department of Infectious Diseases, Central Adelaide Local Health Network, Adelaide, Australia
| | - Stephen P Kidd
- Australian Center for Antimicrobial Resistance Ecology, University of Adelaide, Adelaide, Australia
- Research Center for Infectious Disease, School of Biological Science, University of Adelaide, Adelaide, Australia
| | - Katharina Richter
- Department of Surgery, Richter Lab, Basil Hetzel Institute for Translational Health Research, University of Adelaide, Adelaide, Australia
- Institute for Photonics and Advanced Sensing, University of Adelaide, Adelaide, Australia
| | - Gerald J Atkins
- Center for Orthopedic and Trauma Research, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, Australia
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3
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Zhao Y, Mao W, Liu B, Wang YF, Zhang SY, Guo LL, Qian YH, Gong ZG, Zhao JM, Yang XL, Qu GG, Hasi SR, Bai YT, Cao JS. Preparation of ceftiofur-encapsulated hen-egg low-density lipoproteins and their antibacterial effects on intracellular Staphylococcus aureus. Int J Biol Macromol 2024:134840. [PMID: 39217040 DOI: 10.1016/j.ijbiomac.2024.134840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 08/03/2024] [Accepted: 08/16/2024] [Indexed: 09/04/2024]
Abstract
Hen egg low-density lipoprotein (heLDL), as alternative of serum-derived LDL, was used as drug delivery system of ceftiofur (CEF). The CEF-loaded hen egg low-density lipoprotein (CEF-heLDL) with complete apolipoprotein structure and high drug loading rate was synthesized, possesses suitable particle size. CEF-heLDL undergoes cellular uptake and colocalizes with lysosomes in vitro. An intracellular infection model of the bovine endometrial epithelial cells and a coeliac-induced inflammation model of mice by Staphylococcus aureus (S. aureus) were established, and significantly lower intracellular S. aureus levels of CEF-heLDL group than CEF-free group (P < 0.001) was observed. The antibacterial efficacy was sustained for 24 h. Up to 400 mg/kg of CEF-heLDL, 20 times the clinical practice, were intraperitoneally administrated, and no significant toxicity signs on mice were observed. HeLDLs is an effective, safe, and cheap drug carrier, and could also be used for transmembrane delivering other antibiotics.
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Affiliation(s)
- Yi Zhao
- Laboratory of Veterinary Clinical Pharmacology, College of Veterinary Medicine, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China; Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China
| | - Wei Mao
- Laboratory of Veterinary Clinical Pharmacology, College of Veterinary Medicine, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China; Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China
| | - Bo Liu
- Laboratory of Veterinary Clinical Pharmacology, College of Veterinary Medicine, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China; Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China
| | - Yong-Fei Wang
- Laboratory of Veterinary Clinical Pharmacology, College of Veterinary Medicine, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China; Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China; Inner Mongolia Medical University, Hohhot 010030, China
| | - Shuang-Yi Zhang
- Laboratory of Veterinary Clinical Pharmacology, College of Veterinary Medicine, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China; Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China
| | - Li-Li Guo
- Laboratory of Veterinary Clinical Pharmacology, College of Veterinary Medicine, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China; Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China
| | - Ying-Hong Qian
- Inner Mongolia Academy of Agricultural & Animal Husbandry Science, Hohhot 010010, China
| | - Zhi-Guo Gong
- Laboratory of Veterinary Clinical Pharmacology, College of Veterinary Medicine, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China; Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China
| | - Jia-Min Zhao
- Laboratory of Veterinary Clinical Pharmacology, College of Veterinary Medicine, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China; Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China
| | - Xiao-Lin Yang
- Laboratory of Veterinary Clinical Pharmacology, College of Veterinary Medicine, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China; Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China
| | - Gang-Gang Qu
- Laboratory of Veterinary Clinical Pharmacology, College of Veterinary Medicine, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China; Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China
| | - Su-Rong Hasi
- Laboratory of Veterinary Clinical Pharmacology, College of Veterinary Medicine, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China.
| | - Yu-Ting Bai
- Laboratory of Veterinary Clinical Pharmacology, College of Veterinary Medicine, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China; Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China.
| | - Jin-Shan Cao
- Laboratory of Veterinary Clinical Pharmacology, College of Veterinary Medicine, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China; Key Laboratory of Clinical Diagnosis and Treatment Techniques for Animal Disease, Ministry of Agriculture, Inner Mongolia Agricultural University, No. 29, Erdosdong Road, Saihan District, 010011 Hohhot City, China.
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Beadell B, Yamauchi J, Wong-Beringer A. Comparative in vitro efficacy of antibiotics against the intracellular reservoir of Staphylococcus aureus. J Antimicrob Chemother 2024:dkae241. [PMID: 39073778 DOI: 10.1093/jac/dkae241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 06/26/2024] [Indexed: 07/30/2024] Open
Abstract
Staphylococcus aureus (SA) is a leading cause of bloodstream infection. The liver represents the sentinel immune organ for clearance of bloodstream pathogens and eradication of intracellular SA from liver-resident macrophages (Kupffer cells, KCs) eliminates the likely pathogenic reservoir that contributes to persistent bacteraemia. OBJECTIVES We assessed antimicrobial activity at phagolysosome-mimicking pH, intracellular penetration, and SA eradication within KCs in vitro for clinically prescribed antistaphylococcal agents alone or in combination: vancomycin, daptomycin, ceftaroline, ceftobiprole, oritavancin, oxacillin, cefazolin; rifampin and fosfomycin. METHODS pH-adjusted broth microdilution assays, intracellular bioaccumulation assays, and intracellular killing assays against clinical bloodstream isolates were performed using a murine KC line with study agents. RESULTS Rifampin and β-lactams exhibited enhanced activity [2- to 16-fold minimum inhibitory concentrations (MIC) decrease] at phagolysosomal pH while vancomycin, oritavancin, daptomycin and fosfomycin demonstrated reduced activity (2- to 32-fold MIC increase in order of least to greatest potency reduction). All agents evaluated had poor to modest intracellular to extracellular concentration ratios (0.024-7.8), with exceptions of rifampin and oritavancin (intracellular to extracellular ratios of 17.4 and 78.2, respectively). Finally, we showed that the first-line treatment for SA bacteraemia (SAB), vancomycin, performed worse than all other tested antibiotics in eradicating intracellular SA at human Cmax concentration (0.20 log cfu decrease), while oritavancin performed better than all other agents alone (2.05 versus 1.06-1.36 log cfu decrease). CONCLUSIONS Our findings raise concerns about the efficacy of commonly prescribed antibiotics against intracellular SA reservoirs and emphasize the need to consider targeting pathogen eradication from the liver to achieve early control of SAB.
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Affiliation(s)
- Brent Beadell
- Alfred E. Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, USA
| | - Joe Yamauchi
- Alfred E. Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, USA
| | - Annie Wong-Beringer
- Alfred E. Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, USA
- Department of Pharmacy, Huntington Hospital, Pasadena, CA, USA
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5
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Alves J, Vrieling M, Ring N, Yebra G, Pickering A, Prajsnar TK, Renshaw SA, Fitzgerald JR. Experimental evolution of Staphylococcus aureus in macrophages: dissection of a conditional adaptive trait promoting intracellular survival. mBio 2024; 15:e0034624. [PMID: 38682911 PMCID: PMC11237485 DOI: 10.1128/mbio.00346-24] [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: 02/05/2024] [Accepted: 03/26/2024] [Indexed: 05/01/2024] Open
Abstract
Staphylococcus aureus is a major pathogen associated with important diseases in humans and animals. Macrophages are a key component of the innate immune response to S. aureus infection and play a major role in disease outcomes. To investigate the adaptive evolution of S. aureus in response to macrophages, we developed an experimental infection assay. S. aureus strains representing major human epidemic clones were passaged many times in a macrophage cell line, accumulating mutations in an array of genomic loci. Phenotypic analysis revealed the emergence of a lineage exhibiting increased survival in macrophages and human blood, and resistance to vancomycin. The evolved lineage exhibited a previously undescribed small colony variant (SCV) phenotype characterized by hyper-pigmentation, which resulted from a missense mutation in rsbW. Notably, the novel SCV was a conditional adaptive trait that was unstable in nutrient-replete conditions in vitro, rapidly converting from hyper-pigmented SCV to a non-pigmented large colony variant via spontaneous sigB deletion events. Importantly, we identified similar deletions in the genome sequences of a limited number of clinical S. aureus isolates from public databases, indicating that related events may occur during clinical infection. Experimental infection of zebrafish did not reveal a difference in virulence between parent and novel SCV but demonstrated an in vivo fitness cost for the compensatory sigB deletion events. Taken together, we report an experimental evolutionary approach for investigating bacterial innate immune cell interactions, revealing a conditional adaptation that promotes S. aureus survival in macrophages and resistance to vancomycin. IMPORTANCE Staphylococcus aureus is an important human bacterial pathogen. The host response to S. aureus involves the production of innate immune cells such as macrophages which are important for fighting infection. Here we report a new model of experimental evolution for studying how S. aureus can evade killing by macrophages. We identified a novel adaptive phenotype that promotes survival in macrophages and blood and resistance to antibiotics. The phenotype is lost rapidly upon growth in nutrient-rich conditions via disruption of the alternative sigma factor sigB, revealing a conditional niche-specific fitness advantage. Genomic analysis of clinical isolates suggests similar adaptations may occur during human infections. Our model may be used broadly to identify adaptations of S. aureus to the innate immune response.
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Affiliation(s)
- Joana Alves
- The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, Edinburgh, United Kingdom
| | - Manouk Vrieling
- The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, Edinburgh, United Kingdom
| | - Natalie Ring
- The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, Edinburgh, United Kingdom
| | - Gonzalo Yebra
- The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, Edinburgh, United Kingdom
| | - Amy Pickering
- The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, Edinburgh, United Kingdom
| | - Tomasz K. Prajsnar
- Florey Institute, Bateson Centre and Division of Clinical Medicine, School of Medicine and Population Health, Sheffield, United Kingdom
| | - Stephen A. Renshaw
- Florey Institute, Bateson Centre and Division of Clinical Medicine, School of Medicine and Population Health, Sheffield, United Kingdom
| | - J. Ross Fitzgerald
- The Roslin Institute, University of Edinburgh, Easter Bush, Midlothian, Edinburgh, United Kingdom
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6
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Volk CF, Proctor RA, Rose WE. The Complex Intracellular Lifecycle of Staphylococcus aureus Contributes to Reduced Antibiotic Efficacy and Persistent Bacteremia. Int J Mol Sci 2024; 25:6486. [PMID: 38928191 PMCID: PMC11203666 DOI: 10.3390/ijms25126486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 06/03/2024] [Accepted: 06/07/2024] [Indexed: 06/28/2024] Open
Abstract
Staphylococcus aureus bacteremia continues to be associated with significant morbidity and mortality, despite improvements in diagnostics and management. Persistent infections pose a major challenge to clinicians and have been consistently shown to increase the risk of mortality and other infectious complications. S. aureus, while typically not considered an intracellular pathogen, has been proven to utilize an intracellular niche, through several phenotypes including small colony variants, as a means for survival that has been linked to chronic, persistent, and recurrent infections. This intracellular persistence allows for protection from the host immune system and leads to reduced antibiotic efficacy through a variety of mechanisms. These include antimicrobial resistance, tolerance, and/or persistence in S. aureus that contribute to persistent bacteremia. This review will discuss the challenges associated with treating these complicated infections and the various methods that S. aureus uses to persist within the intracellular space.
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Affiliation(s)
- Cecilia F. Volk
- Pharmacy Practice and Translational Research Division, School of Pharmacy, Pharmacy University of Wisconsin-Madison, Madison, WI 53705, USA;
| | - Richard A. Proctor
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, USA
- Department of Medical Microbiology and Immunology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Warren E. Rose
- Pharmacy Practice and Translational Research Division, School of Pharmacy, Pharmacy University of Wisconsin-Madison, Madison, WI 53705, USA;
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, USA
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7
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van den Biggelaar RHGA, Walburg KV, van den Eeden SJF, van Doorn CLR, Meiler E, de Ries AS, Meijer AH, Ottenhoff THM, Saris A. Identification of kinase modulators as host-directed therapeutics against intracellular methicillin-resistant Staphylococcus aureus. Front Cell Infect Microbiol 2024; 14:1367938. [PMID: 38590439 PMCID: PMC10999543 DOI: 10.3389/fcimb.2024.1367938] [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: 01/09/2024] [Accepted: 03/11/2024] [Indexed: 04/10/2024] Open
Abstract
The increasing prevalence of antimicrobial-resistant Staphylococcus aureus strains, especially methicillin-resistant S. aureus (MRSA), poses a threat to successful antibiotic treatment. Unsuccessful attempts to develop a vaccine and rising resistance to last-resort antibiotics urge the need for alternative treatments. Host-directed therapy (HDT) targeting critical intracellular stages of S. aureus emerges as a promising alternative, potentially acting synergistically with antibiotics and reducing the risk of de novo drug resistance. We assessed 201 ATP-competitive kinase inhibitors from Published Kinase Inhibitor Sets (PKIS1 and PKIS2) against intracellular MRSA. Seventeen hit compounds were identified, of which the two most effective and well-tolerated hit compounds (i.e., GW633459A and GW296115X) were selected for further analysis. The compounds did not affect planktonic bacterial cultures, while they were active in a range of human cell lines of cervical, skin, lung, breast and monocyte origin, confirming their host-directed mechanisms. GW633459A, structurally related to lapatinib, exhibited an HDT effect on intracellular MRSA independently of its known human epidermal growth factor receptor (EGFR)/(HER) kinase family targets. GW296115X activated adenosine monophosphate-activated protein kinase (AMPK), thereby enhancing bacterial degradation via autophagy. Finally, GW296115X not only reduced MRSA growth in human cells but also improved the survival rates of MRSA-infected zebrafish embryos, highlighting its potential as HDT.
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Affiliation(s)
- Robin H. G. A. van den Biggelaar
- Leiden University Center for Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands
- Institute of Biology Leiden, Leiden University, Leiden, Netherlands
| | - Kimberley V. Walburg
- Leiden University Center for Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands
| | - Susan J. F. van den Eeden
- Leiden University Center for Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands
| | - Cassandra L. R. van Doorn
- Leiden University Center for Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands
| | - Eugenia Meiler
- Global Health Medicines R&D, GlaxoSmithKline, Tres Cantos, Spain
| | - Alex S. de Ries
- Institute of Biology Leiden, Leiden University, Leiden, Netherlands
| | | | - Tom H. M. Ottenhoff
- Leiden University Center for Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands
| | - Anno Saris
- Leiden University Center for Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands
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8
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Hosmann A, Moser MM, van Os W, Gramms L, al Jalali V, Sanz Codina M, Plöchl W, Lier C, Kees F, Dorn C, Rössler K, Reinprecht A, Zeitlinger M. Linezolid brain penetration in neurointensive care patients. J Antimicrob Chemother 2024; 79:669-677. [PMID: 38323369 PMCID: PMC10904716 DOI: 10.1093/jac/dkae025] [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: 09/27/2023] [Accepted: 01/16/2024] [Indexed: 02/08/2024] Open
Abstract
BACKGROUND Linezolid exposure in critically ill patients is associated with high inter-individual variability, potentially resulting in subtherapeutic antibiotic exposure. Linezolid exhibits good penetration into the CSF, but its penetration into cerebral interstitial fluid (ISF) is unknown. OBJECTIVES To determine linezolid penetration into CSF and cerebral ISF of neurointensive care patients. PATIENTS AND METHODS Five neurocritical care patients received 600 mg of linezolid IV twice daily for treatment of extracerebral infections. At steady state, blood and CSF samples were collected from arterial and ventricular catheters, and microdialysate was obtained from a cerebral intraparenchymal probe. RESULTS The median fAUC0-24 was 57.6 (24.9-365) mg·h/L in plasma, 64.1 (43.5-306.1) mg·h/L in CSF, and 27.0 (10.7-217.6) mg·h/L in cerebral ISF. The median penetration ratio (fAUCbrain_or_CSF/fAUCplasma) was 0.5 (0.25-0.81) for cerebral ISF and 0.92 (0.79-1) for CSF. Cerebral ISF concentrations correlated well with plasma (R = 0.93, P < 0.001) and CSF levels (R = 0.93, P < 0.001).The median fAUC0-24/MIC ratio was ≥100 in plasma and CSF for MICs of ≤0.5 mg/L, and in cerebral ISF for MICs of ≤0.25 mg/L. The median fT>MIC was ≥80% of the dosing interval in CSF for MICs of ≤0.5 mg/L, and in plasma and cerebral ISF for MICs of ≤0.25 mg/L. CONCLUSIONS Linezolid demonstrates a high degree of cerebral penetration, and brain concentrations correlate well with plasma and CSF levels. However, substantial variability in plasma levels, and thus cerebral concentrations, may result in subtherapeutic tissue concentrations in critically ill patients with standard dosing, necessitating therapeutic drug monitoring.
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Affiliation(s)
- Arthur Hosmann
- Department of Neurosurgery, Medical University of Vienna, Vienna, Austria
| | - Miriam M Moser
- Department of Neurosurgery, Medical University of Vienna, Vienna, Austria
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Wisse van Os
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Leon Gramms
- Department of Neurosurgery, Medical University of Vienna, Vienna, Austria
| | - Valentin al Jalali
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Maria Sanz Codina
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Walter Plöchl
- Department of Anesthesia, General Intensive Care Medicine and Pain Management, Medical University of Vienna, Vienna, Austria
| | - Constantin Lier
- Institute of Pharmacy, University of Regensburg, Regensburg, Germany
| | - Frieder Kees
- Department of Pharmacology, University of Regensburg, Regensburg, Germany
| | - Christoph Dorn
- Institute of Pharmacy, University of Regensburg, Regensburg, Germany
| | - Karl Rössler
- Department of Neurosurgery, Medical University of Vienna, Vienna, Austria
| | - Andrea Reinprecht
- Department of Neurosurgery, Medical University of Vienna, Vienna, Austria
| | - Markus Zeitlinger
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
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9
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Day NJ, Santucci P, Gutierrez MG. Host cell environments and antibiotic efficacy in tuberculosis. Trends Microbiol 2024; 32:270-279. [PMID: 37709598 DOI: 10.1016/j.tim.2023.08.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/18/2023] [Accepted: 08/23/2023] [Indexed: 09/16/2023]
Abstract
The aetiologic agent of tuberculosis (TB), Mycobacterium tuberculosis (Mtb), can survive, persist, and proliferate in a variety of heterogeneous subcellular compartments. Therefore, TB chemotherapy requires antibiotics crossing multiple biological membranes to reach distinct subcellular compartments and target these bacterial populations. These compartments are also dynamic, and our understanding of intracellular pharmacokinetics (PK) often represents a challenge for antitubercular drug development. In recent years, the development of high-resolution imaging approaches in the context of host-pathogen interactions has revealed the intracellular distribution of antibiotics at a new level, yielding discoveries with important clinical implications. In this review, we describe the current knowledge regarding cellular PK of antibiotics and the complexity of drug distribution within the context of TB. We also discuss the recent advances in quantitative imaging and highlight their applications for drug development in the context of how intracellular environments and microbial localisation affect TB treatment efficacy.
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Affiliation(s)
- Nathan J Day
- Host-Pathogen Interactions in Tuberculosis Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Pierre Santucci
- Host-Pathogen Interactions in Tuberculosis Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Maximiliano G Gutierrez
- Host-Pathogen Interactions in Tuberculosis Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.
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10
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Chen Y, Jiang Y, Xue T, Cheng J. Strategies for the eradication of intracellular bacterial pathogens. Biomater Sci 2024; 12:1115-1130. [PMID: 38284808 DOI: 10.1039/d3bm01498c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2024]
Abstract
Intracellular pathogens affect a significant portion of world population and cause millions of deaths each year. They can invade host cells and survive inside them and are extremely resistant to immune systems and antibiotics. Current treatments have limitations, and therefore, new effective therapies are needed to combat this ongoing health challenge. Active research efforts have been made to develop many new strategies to eradicate these intracellular pathogens. In this review, we focus on the intracellular bacterial pathogens and first introduce several representative intracellular bacteria and the diseases they cause. We then discuss the challenges in eradicating these bacteria and summarize the current therapeutics for intracellular bacteria. Finally, recent advances in intracellular bacteria eradication are highlighted.
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Affiliation(s)
- Yingying Chen
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
| | - Yunjiang Jiang
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- BayRay Innovation Center, Shenzhen Bay Laboratory, Shenzhen, 518071, China
| | - Tianrui Xue
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Jianjun Cheng
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Biomaterials and Drug Delivery Laboratory, School of Engineering, Westlake University, Hangzhou 310024, China
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11
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Saseedharan S, Zirpe K, Mehta Y, Dubey D, Sutar A, Debnath K, Newale S. Efficacy and Safety of Oral and IV Levonadifloxacin Therapy in Management of Bacterial Infections: Findings of a Prospective, Observational, Multi-center, Post-marketing Surveillance Study. Cureus 2024; 16:e55178. [PMID: 38558736 PMCID: PMC10980586 DOI: 10.7759/cureus.55178] [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] [Accepted: 02/28/2024] [Indexed: 04/04/2024] Open
Abstract
Background Antimicrobial resistance by bacteria poses a substantial threat to morbidity and mortality worldwide, and treatment of resistant infections is a challenge for the treating clinician. Levonadifloxacin is a novel broad-spectrum agent belonging to the benzoquinolizine subclass of quinolone, which can be used by both oral and intravenous administration for the treatment of infections caused by gram-positive organisms, including methicillin-resistant Staphylococcus aureus (MRSA). Patients and methods This prescription event monitoring study captured data from 1266 patients receiving levonadifloxacin (oral and/or IV) in a real-world setting to assess the safety and efficacy in the treatment of various bacterial infections. The duration of the study was 18 months. Study outcomes were clinical success and microbial success at the end of therapy. Global assessments were done for safety and efficacy at the end of therapy using a 5-point Likert scale (excellent, very good, good, satisfactory, and poor). Results The mean (median) duration of therapy was 7.2 (7.0) days, with a median time to clinical improvement of four days. Oral therapy was administered to 224 patients; 940 received IV, and 102 received IV followed by oral therapy. Patients were prescribed levonadifloxacin for gram-positive infections, skin and soft tissue infections, diabetic foot infections, septicemia, catheter-related blood-stream infections, bone and joint infections, febrile neutropenia, and respiratory infections, including COVID-19 pneumonia. The clinical cure on the eighth day was 95.7%, whereas the microbial success on the eighth day was 93.3% (n=60). For different types of infections, the clinical success rates ranged from 85.2% to 100%. There were only 30 treatment-emergent adverse events reported in 29 patients. Overall, about 95.6% of patients rated the efficacy as good to excellent, whereas only 3.8% of patients rated it satisfactory; for safety, 95.7% of patients rated it as good to excellent, with only 3.9% of patients rated it as satisfactory. Conclusions The excellent safety and efficacy profile of levonadifloxacin, when administered as an oral or intravenous therapy, makes it a desirable treatment modality for the management of various bacterial infections, including those caused by resistant pathogens such as MRSA and quinolone-resistant Staphylococcus aureus (QRSA). Features of levonadifloxacin, such as availability in both IV and oral form, minimal drug-drug interactions, lack of the need to adjust dosages in renal and hepatically impaired patients along with a broad spectrum of coverage, make it a suitable agent that meets several unmet clinical needs of physicians.
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Affiliation(s)
| | - Kapil Zirpe
- Neurocritical Care, Ruby Hall Clinic, Grant Medical Foundation, Pune, IND
| | - Yatin Mehta
- Medanta Institute of Critical Care and Anesthesiology, Medanta - The Medicity, Gurugram, IND
| | | | - Anand Sutar
- Critical Care Medicine, Apollo Hospitals, Bengaluru, IND
| | - Khokan Debnath
- Clinical Operations, Regulatory Affairs, Pharmacovigilance and Quality Assurance, Wockhardt Ltd., Mumbai, IND
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12
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Kelly JJ, Dalesandro BE, Liu Z, Chordia MD, Ongwae GM, Pires MM. Measurement of Accumulation of Antibiotics to Staphylococcus aureus in Phagosomes of Live Macrophages. Angew Chem Int Ed Engl 2024; 63:e202313870. [PMID: 38051128 PMCID: PMC10799677 DOI: 10.1002/anie.202313870] [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: 10/16/2023] [Revised: 11/28/2023] [Accepted: 12/05/2023] [Indexed: 12/07/2023]
Abstract
Staphylococcus aureus (S. aureus) has evolved the ability to persist after uptake into host immune cells. This intracellular niche enables S. aureus to potentially escape host immune responses and survive the lethal actions of antibiotics. While the elevated tolerance of S. aureus to small-molecule antibiotics is likely to be multifactorial, we pose that there may be contributions related to permeation of antibiotics into phagocytic vacuoles, which would require translocation across two mammalian bilayers. To empirically test this, we adapted our recently developed permeability assay to determine the accumulation of FDA-approved antibiotics into phagocytic vacuoles of live macrophages. Bioorthogonal reactive handles were metabolically anchored within the surface of S. aureus, and complementary tags were chemically added to antibiotics. Following phagocytosis of tagged S. aureus cells, we were able to specifically analyze the arrival of antibiotics within the phagosomes of infected macrophages. Our findings enabled the determination of permeability differences between extra- and intracellular S. aureus, thus providing a roadmap to dissect the contribution of antibiotic permeability to intracellular pathogens.
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Affiliation(s)
| | | | - Zichen Liu
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA
| | - Mahendra D. Chordia
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA
| | - George M. Ongwae
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA
| | - Marcos M. Pires
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA
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13
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Goormaghtigh F, Van Bambeke F. Understanding Staphylococcus aureus internalisation and induction of antimicrobial tolerance. Expert Rev Anti Infect Ther 2024; 22:87-101. [PMID: 38180805 DOI: 10.1080/14787210.2024.2303018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 01/04/2024] [Indexed: 01/07/2024]
Abstract
INTRODUCTION Staphylococcus aureus, a human commensal, is also one of the most common and serious pathogens for humans. In recent years, its capacity to survive and replicate in phagocytic and non-phagocytic cells has been largely demonstrated. In these intracellular niches, bacteria are shielded from the immune response and antibiotics, turning host cells into long-term infectious reservoirs. Moreover, neutrophils carry intracellular bacteria in the bloodstream, leading to systemic spreading of the disease. Despite the serious threat posed by intracellular S. aureus to human health, the molecular mechanisms behind its intracellular survival and subsequent antibiotic treatment failure remain elusive. AREA COVERED We give an overview of the killing mechanisms of phagocytes and of the impressive arsenal of virulence factors, toxins and stress responses deployed by S. aureus as a response. We then discuss the different barriers to antibiotic activity in this intracellular niche and finally describe innovative strategies to target intracellular persisting reservoirs. EXPERT OPINION Intracellular niches represent a challenge in terms of diagnostic and treatment. Further research using ad-hoc in-vivo models and single cell approaches are needed to better understand the molecular mechanisms underlying intracellular survival and tolerance to antibiotics in order to identify strategies to eliminate these persistent bacteria.
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Affiliation(s)
- Frédéric Goormaghtigh
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Françoise Van Bambeke
- Pharmacologie cellulaire et moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
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14
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Bai S, Song J, Pu H, Yu Y, Song W, Chen Z, Wang M, Campbell-Valois FX, Wong WL, Cai Q, Wan M, Zhang C, Bai Y, Feng X. Chemical Biology Approach to Reveal the Importance of Precise Subcellular Targeting for Intracellular Staphylococcus aureus Eradication. J Am Chem Soc 2023; 145:23372-23384. [PMID: 37838963 DOI: 10.1021/jacs.3c09587] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Intracellular bacterial pathogens, such as Staphylococcus aureus, that may hide in intracellular vacuoles represent the most significant manifestation of bacterial persistence. They are critically associated with chronic infections and antibiotic resistance, as conventional antibiotics are ineffective against such intracellular persisters due to permeability issues and mechanistic reasons. Direct subcellular targeting of S. aureus vacuoles suggests an explicit opportunity for the eradication of these persisters, but a comprehensive understanding of the chemical biology nature and significance of precise S. aureus vacuole targeting remains limited. Here, we report an oligoguanidine-based peptidomimetic that effectively targets and eradicates intracellular S. aureus persisters in the phagolysosome lumen, and this oligomer was utilized to reveal the mechanistic insights linking precise targeting to intracellular antimicrobial efficacy. The oligomer has high cellular uptake via a receptor-mediated endocytosis pathway and colocalizes with S. aureus persisters in phagolysosomes as a result of endosome-lysosome interconversion and lysosome-phagosome fusion. Moreover, the observation of a bacterium's altered susceptibility to the oligomer following a modification in its intracellular localization offers direct evidence of the critical importance of precise intracellular targeting. In addition, eradication of intracellular S. aureus persisters was achieved by the oligomer's membrane/DNA dual-targeting mechanism of action; therefore, its effectiveness is not hampered by the hibernation state of the persisters. Such precise subcellular targeting of S. aureus vacuoles also increases the agent's biocompatibility by minimizing its interaction with other organelles, endowing excellent in vivo bacterial targeting and therapeutic efficacy in animal models.
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Affiliation(s)
- Silei Bai
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, and School of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
- National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, Hunan 410128, China
| | - Junfeng Song
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, and School of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Huangsheng Pu
- College of Advanced Interdisciplinary Studies & Hunan Provincial Key Laboratory of Novel NanoOptoelectronic Information Materials and Devices, National University of Defense Technology, Changsha, Hunan 410073, China
- Nanhu Laser Laboratory, National University of Defense Technology, Changsha 410073, China
| | - Yue Yu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, and School of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Wenwen Song
- College of Biology, Hunan University, Changsha, Hunan 410082, China
| | - Zhiyong Chen
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, and School of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Min Wang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, and School of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | | | - Wing-Leung Wong
- State Key Laboratory of Chemical Biology and Drug Discovery, Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon 999077, Hong Kong SAR, China
| | - Qingyun Cai
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, and School of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Muyang Wan
- College of Biology, Hunan University, Changsha, Hunan 410082, China
| | - Chunhui Zhang
- College of Biology, Hunan University, Changsha, Hunan 410082, China
| | - Yugang Bai
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, and School of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Xinxin Feng
- State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan Provincial Key Laboratory of Biomacromolecular Chemical Biology, and School of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
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15
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Beam JE, Wagner NJ, Lu KY, Parsons JB, Fowler VG, Rowe SE, Conlon BP. Inflammasome-mediated glucose limitation induces antibiotic tolerance in Staphylococcus aureus. iScience 2023; 26:107942. [PMID: 37790275 PMCID: PMC10543182 DOI: 10.1016/j.isci.2023.107942] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 06/27/2023] [Accepted: 09/13/2023] [Indexed: 10/05/2023] Open
Abstract
Staphylococcus aureus is a leading human pathogen that frequently causes relapsing infections. The failure of antibiotics to eradicate infection contributes to infection relapse. Host-pathogen interactions have a substantial impact on antibiotic susceptibility and the formation of antibiotic tolerant cells. In this study, we interrogate how a major S. aureus virulence factor, α-toxin, interacts with macrophages to alter the microenvironment of the pathogen, thereby influencing its susceptibility to antibiotics. We find α-toxin-mediated activation of the NLRP3 inflammasome induces antibiotic tolerance. Induction of tolerance is driven by increased glycolysis in the host cells, resulting in glucose limitation and ATP depletion in S. aureus. Additionally, inhibition of NLRP3 activation improves antibiotic efficacy in vitro and in vivo, suggesting that this strategy has potential as a host-directed therapeutic to improve outcomes. Our findings identify interactions between S. aureus and the host that result in metabolic crosstalk that can determine the outcome of antimicrobial therapy.
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Affiliation(s)
- Jenna E. Beam
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nikki J. Wagner
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Kuan-Yi Lu
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Joshua B. Parsons
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Division of Infectious Diseases, Duke University School of Medicine, Durham, NC, USA
| | - Vance G. Fowler
- Division of Infectious Diseases, Duke University School of Medicine, Durham, NC, USA
| | - Sarah E. Rowe
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Brian P. Conlon
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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16
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Kelly JJ, Dalesandro BE, Liu Z, Chordia MD, Ongwae GM, Pires MM. Measurement of Accumulation of Antibiotics to Staphylococcus aureus in Phagosomes of Live Macrophages. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.13.528196. [PMID: 36824967 PMCID: PMC9949086 DOI: 10.1101/2023.02.13.528196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Staphylococcus aureus ( S. aureus ) has evolved the ability to persist after uptake into host immune cells. This intracellular niche enables S. aureus to potentially escape host immune responses and survive the lethal actions of antibiotics. While the elevated tolerance of S. aureus to small-molecule antibiotics is likely to be multifactorial, we pose that there may be contributions related to permeation of antibiotics into phagocytic vacuoles, which would require translocation across two mammalian bilayers. To empirically test this, we adapted our recently developed permeability assay to determine the accumulation of FDA-approved antibiotics into phagocytic vacuoles of live macrophages. Bioorthogonal reactive handles were metabolically anchored within the surface of S. aureus, and complementary tags were chemically added to antibiotics. Following phagocytosis of tagged S. aureus cells, we were able to specifically analyze the arrival of antibiotics within the phagosomes of infected macrophages. Our findings enabled the determination of permeability differences between extra- and intracellular S. aureus , thus providing a roadmap to dissect the contribution of antibiotic permeability to intracellular pathogens.
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17
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Becker K. Detection, Identification and Diagnostic Characterization of the Staphylococcal Small Colony-Variant (SCV) Phenotype. Antibiotics (Basel) 2023; 12:1446. [PMID: 37760742 PMCID: PMC10525764 DOI: 10.3390/antibiotics12091446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 09/08/2023] [Accepted: 09/11/2023] [Indexed: 09/29/2023] Open
Abstract
While modern molecular methods have decisively accelerated and improved microbiological diagnostics, phenotypic variants still pose a challenge for their detection, identification and characterization. This particularly applies if they are unstable and hard to detect, which is the case for the small-colony-variant (SCV) phenotype formed by staphylococci. On solid agar media, staphylococcal SCVs are characterized by tiny colonies with deviant colony morphology. Their reduced growth rate and fundamental metabolic changes are the result of their adaptation to an intracellular lifestyle, regularly leading to specific auxotrophies, such as for menadione, hemin or thymidine. These alterations make SCVs difficult to recognize and render physiological, biochemical and other growth-based methods such as antimicrobial susceptibility testing unreliable or unusable. Therefore, diagnostic procedures require prolonged incubation times and, if possible, confirmation by molecular methods. A special approach is needed for auxotrophy testing. However, standardized protocols for SCV diagnostics are missing. If available, SCVs and their putative parental isolates should be genotyped to determine clonality. Since their detection has significant implications for the treatment of the infection, which is usually chronic and relapsing, SCV findings should be specifically reported, commented on, and managed in close collaboration with the microbiological laboratory and the involved clinicians.
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Affiliation(s)
- Karsten Becker
- Friedrich Loeffler-Institute of Medical Microbiology, University Medicine Greifswald, Ferdinand-Sauerbruch-Straße 1, 17489 Greifswald, Germany
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18
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Li M, Yu J, Guo G, Shen H. Interactions between Macrophages and Biofilm during Staphylococcus aureus-Associated Implant Infection: Difficulties and Solutions. J Innate Immun 2023; 15:499-515. [PMID: 37011602 PMCID: PMC10315156 DOI: 10.1159/000530385] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Accepted: 03/16/2023] [Indexed: 04/05/2023] Open
Abstract
Staphylococcus aureus (S. aureus) biofilm is the major cause of failure of implant infection treatment that results in heavy social and economic burden on individuals, families, and communities. Planktonic S. aureus attaches to medical implant surfaces where it proliferates and is wrapped by extracellular polymeric substances, forming a solid and complex biofilm. This provides a stable environment for bacterial growth, infection maintenance, and diffusion and protects the bacteria from antimicrobial agents and the immune system of the host. Macrophages are an important component of the innate immune system and resist pathogen invasion and infection through phagocytosis, antigen presentation, and cytokine secretion. The persistence, spread, or clearance of infection is determined by interplay between macrophages and S. aureus in the implant infection microenvironment. In this review, we discuss the interactions between S. aureus biofilm and macrophages, including the effects of biofilm-related bacteria on the macrophage immune response, roles of myeloid-derived suppressor cells during biofilm infection, regulation of immune cell metabolic patterns by the biofilm environment, and immune evasion strategies adopted by the biofilm against macrophages. Finally, we summarize the current methods that support macrophage-mediated removal of biofilms and emphasize the importance of considering multi-dimensions and factors related to implant-associated infection such as immunity, metabolism, the host, and the pathogen when developing new treatments.
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Affiliation(s)
- Mingzhang Li
- Department of Orthopaedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jinlong Yu
- Department of Orthopaedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Geyong Guo
- Department of Orthopaedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hao Shen
- Department of Orthopaedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
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19
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Eller KA, Stamo DF, McCollum CR, Campos JK, Levy M, Nagpal P, Chatterjee A. Photoactivated antibiotics to treat intracellular infection of bacteria. NANOSCALE ADVANCES 2023; 5:1910-1918. [PMID: 36998655 PMCID: PMC10044578 DOI: 10.1039/d2na00378c] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 11/08/2022] [Indexed: 06/19/2023]
Abstract
Antibiotic resistance combined with pathogen internalization leads to debilitating infections. Here we test novel superoxide producing, stimuli-activated quantum dots (QDs), to treat an intracellular infection of Salmonella enterica serovar Typhimurium in an osteoblast precursor cell line. These QDs are precisely tuned to reduce dissolved oxygen to superoxide and kill bacteria upon stimulation (e.g., light). We show QDs provide tunable clearance at various multiplicities of infection and limited host cell toxicity by modulating their concentration and stimuli intensity, proving the efficacy of superoxide producing QDs for intracellular infection treatment and establishing a framework for further testing in different infection models.
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Affiliation(s)
- Kristen A Eller
- Chemical and Biological Engineering, University of Colorado Boulder Boulder CO 80303 USA
| | - Dana F Stamo
- Chemical and Biological Engineering, University of Colorado Boulder Boulder CO 80303 USA
| | - Colleen R McCollum
- Chemical and Biological Engineering, University of Colorado Boulder Boulder CO 80303 USA
| | - Jocelyn K Campos
- Chemical and Biological Engineering, University of Colorado Boulder Boulder CO 80303 USA
| | - Max Levy
- Chemical and Biological Engineering, University of Colorado Boulder Boulder CO 80303 USA
- Renewable and Sustainable Energy Institute, University of Colorado Boulder Boulder CO 80303 USA
| | - Prashant Nagpal
- Sachi Bioworks Inc., Colorado Technology Center Louisville CO 80027 USA
- Antimicrobial Regeneration Consortium Labs Louisville CO 80027 USA
| | - Anushree Chatterjee
- Chemical and Biological Engineering, University of Colorado Boulder Boulder CO 80303 USA
- Sachi Bioworks Inc., Colorado Technology Center Louisville CO 80027 USA
- Antimicrobial Regeneration Consortium Labs Louisville CO 80027 USA
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20
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Immunomodulatory Effects of Macrolides Considering Evidence from Human and Veterinary Medicine. Microorganisms 2022; 10:microorganisms10122438. [PMID: 36557690 PMCID: PMC9784682 DOI: 10.3390/microorganisms10122438] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/17/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022] Open
Abstract
Macrolide antimicrobial agents have been in clinical use for more than 60 years in both human and veterinary medicine. The discovery of the non-antimicrobial properties of macrolides and the effect of immunomodulation of the inflammatory response has benefited patients with chronic airway diseases and impacted morbidity and mortality. This review examines the evidence of antimicrobial and non-antimicrobial properties of macrolides in human and veterinary medicine with a focus toward veterinary macrolides but including important and relevant evidence from the human literature. The complete story for these complex and important molecules is continuing to be written.
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21
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Kong FYS, Unemo M, Lim SH, Latch N, Williamson DA, Roberts JA, Wallis SC, Parker SL, Landersdorfer CB, Yap T, Fairley CK, Chow EPF, Lewis DA, Hammoud MA, Hocking JS. Optimisation of treatments for oral Neisseria gonorrhoeae infection: Pharmacokinetics Study (STI-PK project) - study protocol for non-randomised clinical trial. BMJ Open 2022; 12:e064782. [PMID: 36368750 PMCID: PMC9660608 DOI: 10.1136/bmjopen-2022-064782] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
INTRODUCTION Neisseria gonorrhoeae infections are common and incidence increasing. Oropharyngeal infections are associated with greater treatment failure compared with other sites and drive transmission to anogenital sites through saliva. Gonococcal resistance is increasing and new treatments are scarce, therefore, clinicians must optimise currently available and emerging treatments in order to have efficacious therapeutic options. This requires pharmacokinetic data from the oral cavity/oropharynx, however, availability of such information is currently limited. METHODS AND ANALYSIS Healthy male volunteers (participants) recruited into the study will receive single doses of either ceftriaxone 1 g, cefixime 400 mg or ceftriaxone 500 mg plus 2 g azithromycin. Participants will provide samples at 6-8 time points (treatment regimen dependent) from four oral sites, two oral fluids, one anorectal swab and blood. Participants will complete online questionnaires about their medical history, sexual practices and any side effects experienced up to days 5-7. Saliva/oral mucosal pH and oral microbiome analysis will be undertaken. Bioanalysis will be conducted by liquid chromatography-mass spectrometry. Drug concentrations over time will be used to develop mathematical models for optimisation of drug dosing regimens and to estimate pharmacodynamic targets of efficacy. ETHICS AND DISSEMINATION This study was approved by Royal Melbourne Hospital Human Research Ethics Committee (60370/MH-2021). The study results will be submitted for publication in peer-reviewed journals and reported at conferences. Summary results will be sent to participants requesting them. All data relevant to the study will be included in the article or uploaded as supplementary information. TRIAL REGISTRATION NUMBER ACTRN12621000339853.
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Affiliation(s)
- Fabian Y S Kong
- Centre for Epidemiology and Biostatistics, School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - Magnus Unemo
- WHO Collaborating Centre for Gonorrhoea and Other STIs, National Reference Laboratory for Sexually Transmitted Infections, Department of Laboratory Medicine, Microbiology, Örebro University, Orebro, Sweden
- Institute for Global Health, University College London, London, UK
| | - Shueh H Lim
- Centre for Epidemiology and Biostatistics, School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
- The Crane General Practice, Melbourne, Victoria, Australia
| | - Ngaire Latch
- Centre for Epidemiology and Biostatistics, School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - Deborah A Williamson
- Department of Infectious Diseases, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia
- Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
- Victorian Infectious Diseases Reference Laboratory, Melbourne, Victoria, Australia
| | - Jason A Roberts
- The University of Queensland Centre for Clinical Research, Brisbane, Queensland, Australia
- Departments of Pharmacy and Intensive Care Medicine, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
- Herston Infectious Diseases Institute, Metro North Health, Brisbane, Queensland, Australia
- Division of Anaesthesiology Critical Care Emergency and Pain Medicine, Nîmes University Hospital, University of Montpellier, Nîmes, France
| | - Steven C Wallis
- The University of Queensland Centre for Clinical Research, Brisbane, Queensland, Australia
| | - Suzanne L Parker
- The University of Queensland Centre for Clinical Research, Brisbane, Queensland, Australia
| | | | - Tami Yap
- Melbourne Dental School, The University of Melbourne, Melbourne, Victoria, Australia
| | - Christopher K Fairley
- Melbourne Sexual Health Centre, Alfred Health, Carlton, Victoria, Australia
- Central Clinical School, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - Eric P F Chow
- Melbourne Sexual Health Centre, Alfred Health, Carlton, Victoria, Australia
- Central Clinical School, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Victoria, Australia
| | - David A Lewis
- Westmead Clinical School and Sydney Institute for Infectious Diseases, The University of Sydney, Sydney, New South Wales, Australia
- Western Sydney Sexual Health Centre, Western Sydney Local Health District, Parramatta, New South Wales, Australia
| | - Mohamed A Hammoud
- Kirby Institute, University of New South Wales, Sydney, New South Wales, Australia
| | - Jane S Hocking
- Centre for Epidemiology and Biostatistics, School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
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22
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Behbahani SB, Kiridena SD, Wijayaratna UN, Taylor C, Anker JN, Tzeng TRJ. pH variation in medical implant biofilms: Causes, measurements, and its implications for antibiotic resistance. Front Microbiol 2022; 13:1028560. [PMID: 36386694 PMCID: PMC9659913 DOI: 10.3389/fmicb.2022.1028560] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 09/22/2022] [Indexed: 01/28/2023] Open
Abstract
The advent of implanted medical devices has greatly improved the quality of life and increased longevity. However, infection remains a significant risk because bacteria can colonize device surfaces and form biofilms that are resistant to antibiotics and the host's immune system. Several factors contribute to this resistance, including heterogeneous biochemical and pH microenvironments that can affect bacterial growth and interfere with antibiotic biochemistry; dormant regions in the biofilm with low oxygen, pH, and metabolites; slow bacterial growth and division; and poor antibody penetration through the biofilm, which may also be regions with poor acid product clearance. Measuring pH in biofilms is thus key to understanding their biochemistry and offers potential routes to detect and treat latent infections. This review covers the causes of biofilm pH changes and simulations, general findings of metabolite-dependent pH gradients, methods for measuring pH in biofilms, effects of pH on biofilms, and pH-targeted antimicrobial-based approaches.
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Affiliation(s)
| | | | | | - Cedric Taylor
- Department of Biological Sciences, Clemson University, Clemson, SC, United States
| | - Jeffrey N. Anker
- Department of Chemistry, Clemson University, Clemson, SC, United States
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23
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Villanueva JA, Crooks AL, Nagy TA, Quintana JLJ, Dalebroux ZD, Detweiler CS. Salmonella enterica Infections Are Disrupted by Two Small Molecules That Accumulate within Phagosomes and Differentially Damage Bacterial Inner Membranes. mBio 2022; 13:e0179022. [PMID: 36135367 PMCID: PMC9601186 DOI: 10.1128/mbio.01790-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 09/06/2022] [Indexed: 11/23/2022] Open
Abstract
Gram-negative bacteria have a robust cell envelope that excludes or expels many antimicrobial agents. However, during infection, host soluble innate immune factors permeabilize the bacterial outer membrane. We identified two small molecules that exploit outer membrane damage to access the bacterial cell. In standard microbiological media, neither compound inhibited bacterial growth nor permeabilized bacterial outer membranes. In contrast, at micromolar concentrations, JAV1 and JAV2 enabled the killing of an intracellular human pathogen, Salmonella enterica serovar Typhimurium. S. Typhimurium is a Gram-negative bacterium that resides within phagosomes of cells from the monocyte lineage. Under broth conditions that destabilized the lipopolysaccharide layer, JAV2 permeabilized the bacterial inner membrane and was rapidly bactericidal. In contrast, JAV1 activity was more subtle: JAV1 increased membrane fluidity, altered reduction potential, and required more time than JAV2 to disrupt the inner membrane barrier and kill bacteria. Both compounds interacted with glycerophospholipids from Escherichia coli total lipid extract-based liposomes. JAV1 preferentially interacted with cardiolipin and partially relied on cardiolipin production for activity, whereas JAV2 generally interacted with lipids and had modest affinity for phosphatidylglycerol. In mammalian cells, neither compound significantly altered mitochondrial membrane potential at concentrations that killed S. Typhimurium. Instead, JAV1 and JAV2 became trapped within acidic compartments, including macrophage phagosomes. Both compounds improved survival of S. Typhimurium-infected Galleria mellonella larvae. Together, these data demonstrate that JAV1 and JAV2 disrupt bacterial inner membranes by distinct mechanisms and highlight how small, lipophilic, amine-substituted molecules can exploit host soluble innate immunity to facilitate the killing of intravesicular pathogens. IMPORTANCE Innovative strategies for developing new antimicrobials are needed. Combining our knowledge of host-pathogen interactions and relevant drug characteristics has the potential to reveal new approaches to treating infection. We identified two compounds with antibacterial activity specific to infection and with limited host cell toxicity. These compounds appeared to exploit host innate immunity to access the bacterium and differentially damage the bacterial inner membrane. Further, both compounds accumulated within Salmonella-containing and other acidic vesicles, a process known as lysosomal trapping, which protects the host and harms the pathogen. The compounds also increased host survival in an insect infection model. This work highlights the ability of host innate immunity to enable small molecules to act as antibiotics and demonstrates the feasibility of antimicrobial targeting of the inner membrane. Additionally, this study features the potential use of lysosomal trapping to enhance the activities of compounds against intravesicular pathogens.
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Affiliation(s)
- Joseph A. Villanueva
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
| | - Amy L. Crooks
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
| | - Toni A. Nagy
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
| | - Joaquin L. J. Quintana
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
| | - Zachary D. Dalebroux
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Corrella S. Detweiler
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
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24
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Vialichka A, Biagi M, Meyer K, Wu T, Shajee A, Tan X, Wenzler E. Activity of Delafloxacin and Levofloxacin against Stenotrophomonas maltophilia at Simulated Plasma and Intrapulmonary pH Values. Microbiol Spectr 2022; 10:e0270521. [PMID: 35862943 PMCID: PMC9431699 DOI: 10.1128/spectrum.02705-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 06/22/2022] [Indexed: 11/20/2022] Open
Abstract
Fluoroquinolones have become a popular treatment option for Stenotrophomonas maltophilia infections. Although levofloxacin is most commonly used, delafloxacin demonstrates comparable in vitro activity when evaluated under standard susceptibility testing conditions at neutral pH. At acidic pH, the activity of the anionic delafloxacin is improved, while the activity of the zwitterionic levofloxacin is reduced. Because the human respiratory tract has a pH of ~6.6 and is the most common site of S. maltophilia infection, it is vital to understand the activity of these agents in this environment. Therefore, levofloxacin and delafloxacin were tested against clinical S. maltophilia isolates via broth microdilution testing (n = 37) and time-kill analysis (n = 5) in neutral cation-adjusted Mueller-Hinton broth (CAMHB) (pH 7.3) and acidic CAMHB (aCAMHB) (pH 6.5). In CAMHB, MIC50 values were similar between levofloxacin and delafloxacin (8 mg/L versus 8 mg/L). In aCAMHB, levofloxacin MICs did not change, while delafloxacin MICs decreased by a median of 4 log2 dilutions (MIC50 values of 8 mg/L versus 0.25 mg/L). In time-kill analyses, levofloxacin and delafloxacin at the maximum drug concentration for the free drug (fCmax) were bactericidal against 3 and 2 isolates in CAMHB, respectively. In aCAMHB, levofloxacin was not bactericidal against any isolate, while delafloxacin was bactericidal against the same 2 isolates. Relative to CAMHB, levofloxacin activity was reduced by 2.5 log10 CFU/mL in aCAMHB, whereas delafloxacin activity was increased 2.7 log10 CFU/mL. Although the bactericidal activity of levofloxacin against S. maltophilia was attenuated in an acidic environment in this study, the increased potency of delafloxacin at pH 6.5 did not translate into improved bactericidal activity in time-kill analyses, compared to pH 7.3. IMPORTANCE Stenotrophomonas maltophilia most often infects the lungs, where the physiologic environment is naturally slightly acidic (pH ~6.6), compared to most parts of the body (such as the bloodstream), which have neutral pH values (~7.4). Pneumonia due to S. maltophilia is often treated with the antibiotic levofloxacin, despite the activity of levofloxacin being known to be impaired at acidic pH. Unfortunately, currently available methods for susceptibility testing of levofloxacin against S. maltophilia are performed at a neutral pH and therefore may not accurately represent the activity of levofloxacin at the site of infection in the lungs. A similar but newer antibiotic in the same class as levofloxacin, namely, delafloxacin, is not affected by being in an acidic environment and may actually work better at lower pH values. Therefore, the purpose of this study was to investigate whether one drug might be better than the other in this setting by testing each agent's ability to kill S. maltophilia at pH 7.3 and pH 6.5. These findings could then be used to design confirmatory studies that may ultimately impact which drug is given to patients with lung infections due to S. maltophilia.
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Affiliation(s)
- Alesia Vialichka
- College of Pharmacy, University of Illinois Chicago, Chicago, Illinois, USA
| | - Mark Biagi
- College of Pharmacy, University of Illinois Chicago, Rockford, Illinois, USA
| | - Kevin Meyer
- College of Pharmacy, University of Illinois Chicago, Chicago, Illinois, USA
| | - Tiffany Wu
- College of Pharmacy, University of Illinois Chicago, Chicago, Illinois, USA
| | - Aisha Shajee
- College of Pharmacy, University of Illinois Chicago, Chicago, Illinois, USA
| | - Xing Tan
- College of Pharmacy, University of Illinois Chicago, Chicago, Illinois, USA
| | - Eric Wenzler
- College of Pharmacy, University of Illinois Chicago, Chicago, Illinois, USA
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25
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Zelmer AR, Nelson R, Richter K, Atkins GJ. Can intracellular Staphylococcus aureus in osteomyelitis be treated using current antibiotics? A systematic review and narrative synthesis. Bone Res 2022; 10:53. [PMID: 35961964 PMCID: PMC9374758 DOI: 10.1038/s41413-022-00227-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/26/2022] [Accepted: 06/15/2022] [Indexed: 11/09/2022] Open
Abstract
Approximately 40% of treatments of chronic and recurrent osteomyelitis fail in part due to bacterial persistence. Staphylococcus aureus, the predominant pathogen in human osteomyelitis, is known to persist by phenotypic adaptation as small-colony variants (SCVs) and by formation of intracellular reservoirs, including those in major bone cell types, reducing susceptibility to antibiotics. Intracellular infections with S. aureus are difficult to treat; however, there are no evidence-based clinical guidelines addressing these infections in osteomyelitis. We conducted a systematic review of the literature to determine the demonstrated efficacy of all antibiotics against intracellular S. aureus relevant to osteomyelitis, including protein biosynthesis inhibitors (lincosamides, streptogramins, macrolides, oxazolidines, tetracyclines, fusidic acid, and aminoglycosides), enzyme inhibitors (fluoroquinolones and ansamycines), and cell wall inhibitors (beta-lactam inhibitors, glycopeptides, fosfomycin, and lipopeptides). The PubMed and Embase databases were screened for articles related to intracellular S. aureus infections that compared the effectiveness of multiple antibiotics or a single antibiotic together with another treatment, which resulted in 34 full-text articles fitting the inclusion criteria. The combined findings of these studies were largely inconclusive, most likely due to the plethora of methodologies utilized. Therefore, the reported findings in the context of the models employed and possible solutions for improved understanding are explored here. While rifampicin, oritavancin, linezolid, moxifloxacin and oxacillin were identified as the most effective potential intracellular treatments, the scientific evidence for these is still relatively weak. We advocate for more standardized research on determining the intracellular effectiveness of antibiotics in S. aureus osteomyelitis to improve treatments and patient outcomes.
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Affiliation(s)
- Anja R Zelmer
- Centre for Orthopaedic and Trauma Research, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, 5000, Australia
| | - Renjy Nelson
- Department of Infectious Diseases, Central Adelaide Local Health Network, Adelaide, SA, 5000, Australia.,Royal Adelaide Hospital, Adelaide, SA, 5000, Australia
| | - Katharina Richter
- Richter Lab, Department of Surgery, Basil Hetzel Institute for Translational Health Research, University of Adelaide, Adelaide, SA, 5011, Australia
| | - Gerald J Atkins
- Centre for Orthopaedic and Trauma Research, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, 5000, Australia.
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26
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Karanja CW, Naganna N, Abutaleb NS, Dayal N, Onyedibe KI, Aryal U, Seleem MN, Sintim HO. Isoquinoline Antimicrobial Agent: Activity against Intracellular Bacteria and Effect on Global Bacterial Proteome. Molecules 2022; 27:5085. [PMID: 36014324 PMCID: PMC9416421 DOI: 10.3390/molecules27165085] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/01/2022] [Accepted: 08/02/2022] [Indexed: 11/16/2022] Open
Abstract
A new class of alkynyl isoquinoline antibacterial compounds, synthesized via Sonogashira coupling, with strong bactericidal activity against a plethora of Gram-positive bacteria including methicillin- and vancomycin-resistant Staphylococcus aureus (S. aureus) strains is presented. HSN584 and HSN739, representative compounds in this class, reduce methicillin-resistant S. aureus (MRSA) load in macrophages, whilst vancomycin, a drug of choice for MRSA infections, was unable to clear intracellular MRSA. Additionally, both HSN584 and HSN739 exhibited a low propensity to develop resistance. We utilized comparative global proteomics and macromolecule biosynthesis assays to gain insight into the alkynyl isoquinoline mechanism of action. Our preliminary data show that HSN584 perturb S. aureus cell wall and nucleic acid biosynthesis. The alkynyl isoquinoline moiety is a new scaffold for the development of potent antibacterial agents against fatal multidrug-resistant Gram-positive bacteria.
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Affiliation(s)
- Caroline W. Karanja
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907, USA
| | - Nimishetti Naganna
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907, USA
| | - Nader S. Abutaleb
- Department of Comparative Pathobiology, Purdue University College of Veterinary Medicine, 625 Harrison Street, West Lafayette, IN 47907, USA
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, 1410 Prices Fork Rd, Blacksburg, VA 24061, USA
| | - Neetu Dayal
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907, USA
| | - Kenneth I. Onyedibe
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907, USA
- Purdue Institute of Inflammation, Immunology and Infectious Disease, West Lafayette, IN 47907, USA
| | - Uma Aryal
- Department of Comparative Pathobiology, Purdue University College of Veterinary Medicine, 625 Harrison Street, West Lafayette, IN 47907, USA
- Purdue Proteomics Facility, Bindley Bioscience Center, Purdue University, West Lafayette, IN 47907, USA
| | - Mohamed N. Seleem
- Department of Comparative Pathobiology, Purdue University College of Veterinary Medicine, 625 Harrison Street, West Lafayette, IN 47907, USA
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, 1410 Prices Fork Rd, Blacksburg, VA 24061, USA
| | - Herman O. Sintim
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, IN 47907, USA
- Purdue Institute of Inflammation, Immunology and Infectious Disease, West Lafayette, IN 47907, USA
- Institute for Drug Discovery, Purdue University, 720 Clinic Drive, West Lafayette, IN 47907, USA
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27
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Hommes JW, Surewaard BGJ. Intracellular Habitation of Staphylococcus aureus: Molecular Mechanisms and Prospects for Antimicrobial Therapy. Biomedicines 2022; 10:1804. [PMID: 36009351 PMCID: PMC9405036 DOI: 10.3390/biomedicines10081804] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 12/23/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infections pose a global health threat, especially with the continuous development of antibiotic resistance. As an opportunistic pathogen, MRSA infections have a high mortality rate worldwide. Although classically described as an extracellular pathogen, many studies have shown over the past decades that MRSA also has an intracellular aspect to its infectious cycle, which has been observed in vitro in both non-professional as well as professional phagocytes. In vivo, MRSA has been shown to establish an intracellular niche in liver Kupffer cells upon bloodstream infection. The staphylococci have evolved various evasion strategies to survive the antimicrobial environment of phagolysosomes and use these compartments to hide from immune cells and antibiotics. Ultimately, the host cells get overwhelmed by replicating bacteria, leading to cell lysis and bacterial dissemination. In this review, we describe the different intracellular aspects of MRSA infection and briefly mention S. aureus evasion strategies. We discuss how this intracellular niche of bacteria may assist in antibiotic tolerance development, and lastly, we describe various new antibacterial strategies that target the intracellular bacterial niche.
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Affiliation(s)
| | - Bas G. J. Surewaard
- Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada;
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28
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Hamad C, Chowdhry M, Sindeldecker D, Bernthal NM, Stoodley P, McPherson EJ. Adaptive antimicrobial resistance, a description of microbial variants, and their relevance to periprosthetic joint infection. Bone Joint J 2022; 104-B:575-580. [PMID: 35491584 PMCID: PMC9948434 DOI: 10.1302/0301-620x.104b5.bjj-2021-1759.r1] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Periprosthetic joint infection (PJI) is a difficult complication requiring a comprehensive eradication protocol. Cure rates have essentially stalled in the last two decades, using methods of antimicrobial cement joint spacers and parenteral antimicrobial agents. Functional spacers with higher-dose antimicrobial-loaded cement and antimicrobial-loaded calcium sulphate beads have emphasized local antimicrobial delivery on the premise that high-dose local antimicrobial delivery will enhance eradication. However, with increasing antimicrobial pressures, microbiota have responded with adaptive mechanisms beyond traditional antimicrobial resistance genes. In this review we describe adaptive resistance mechanisms that are relevant to the treatment of PJI. Some mechanisms are well known, but others are new. The objective of this review is to inform clinicians of the known adaptive resistance mechanisms of microbes relevant to PJI. We also discuss the implications of these adaptive mechanisms in the future treatment of PJI. Cite this article: Bone Joint J 2022;104-B(5):575-580.
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Affiliation(s)
- Christopher Hamad
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Madhav Chowdhry
- Nuffield Department of Primary Care Health Sciences, Kellogg College, University of Oxford, Oxford, UK
| | - Devin Sindeldecker
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, USA,Biomedical Sciences Graduate Program, The Ohio State University, Columbus, Ohio, USA
| | - Nicholas M. Bernthal
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Paul Stoodley
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, USA,Department of Orthopaedics, The Ohio State University, Columbus, Ohio, USA,National Centre for Advanced Tribology at Southampton, Department of Mechanical Engineering, University of Southampton, Southampton, UK
| | - Edward J. McPherson
- Department of Orthopaedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA,Correspondence should be sent to Edward J. McPherson. E-mail:
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29
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The polyamino-isoprenyl potentiator NV716 revives disused antibiotics against Gram-negative bacteria in broth, infected monocytes, or biofilms, by disturbing the barrier effect of their outer membrane. Eur J Med Chem 2022; 238:114496. [DOI: 10.1016/j.ejmech.2022.114496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 05/13/2022] [Accepted: 05/25/2022] [Indexed: 11/24/2022]
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30
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Mehta KD, Sharma JB, Anand A, Reddy N PK, Kadam P, Debnath K, Bhapkar S, Thampi BM. Real-World Evidence of Efficacy and Safety of Levonadifloxacin (Oral and IV) in the Management of Acute Bacterial Skin and Skin Structure Infections (ABSSSI): Findings of a Retrospective, Multi-Center Study. Cureus 2022; 14:e24299. [PMID: 35602817 PMCID: PMC9121184 DOI: 10.7759/cureus.24299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/13/2022] [Indexed: 11/16/2022] Open
Abstract
Background Antimicrobial resistance by bacteria poses a substantial threat to the success in the treatment of acute bacterial skin and skin structure infections (ABSSSI). Levonadifloxacin is a novel benzoquinolizine subclass of quinolone which has a broad spectrum of activity, available in both oral and intravenous formulations for the treatment of skin structure infections caused by Gram-positive pathogens including methicillin-resistant Staphylococcus aureus (MRSA). Patients and methods This prescription event monitoring study captured data of 227 patients receiving levonadifloxacin (oral and/or IV) in a real-world setting to assess the safety and efficacy in the treatment of ABSSSI. Study outcomes were a clinical and microbial success at the end of therapy and safety was assessed based on adverse events reported. Results One hundred and forty patients received IV levonadifloxacin therapy, 76 patients received oral alalevonadifloxacin, and 11 received IV followed by oral therapy. The mean duration of therapy was 7.3 days. Out of 227 patients, MRSA isolates were identified in 79 patients. Clinical success rates with oral, IV, and IV followed by oral levonadifloxacin therapy were 97.3%, 97.8%, and 100% respectively. The overall microbial success rate was 99.2% and only two patients reported two adverse events. Conclusions The excellent safety and efficacy profile of levonadifloxacin on oral and/or intravenous therapy, makes it a desirable treatment modality for management of ABSSSI. Unique features of levonadifloxacin such as availability of both IV and oral form, minimal drug-drug interactions, exemption from dosage adjustment in renal and hepatic impaired patients and a broad spectrum of coverage, makes it a suitable agent meeting several unmet clinical needs in contemporary patients.
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31
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Abstract
Persisters are transiently nongrowing and antibiotic-tolerant phenotypic variants identified in major human pathogens, including intracellular Staphylococcus aureus. Due to their capacity to regrow once the environmental stress is relieved and to promote resistance, persisters possibly contribute to therapeutic failures. While persistence and its related quiescence have been mostly studied under starvation, little is known within host cell environments. Here, we examined how the level of reactive oxygen species (ROS) in different host cells affects dormancy depth of intracellular S. aureus. Using single-cell approaches, we found that host ROS induce variable dormant states in S. aureus persisters, displaying heterogeneous and increased lag times for resuscitation in liquid medium. Dormant persisters displayed decreased translation and energy metabolism, but remained infectious, exiting from dormancy and resuming growth when reinoculated in low-oxidative-stress cells. In high-oxidative-stress cells, ROS-induced ATP depletion was associated with the formation of visible dark foci similar to those induced by the protein aggregation inducer CCCP (carbonyl cyanide m-chlorophenylhydrazone) and with the recruitment of the DnaK-ClpB chaperone system involved in the clearance of protein aggregates. ATP depletion led to higher fractions of dormant persisters than ROS, due to a counterbalancing effect of ROS-induced translational repression, suggesting a pivotal role of translation in the dormant phenotype. Consistently, protein synthesis inhibition limited dormancy to levels similar to those observed in low-oxidative-stress cells. This study supports the hypothesis that intracellular S. aureus persisters can reach heterogeneous dormancy depths and highlights the link between ROS, ATP depletion, dark focus formation, and subsequent dormancy state. IMPORTANCE By their capacity to survive to antibiotic pressure and to regrow and give rise to a susceptible population once this pressure is relieved, intracellular persisters of S. aureus may contribute to explain therapeutic failures and recurrent infections. Here, we show that the level of dormancy and the subsequent capacity to resuscitate from this resting state are dependent on the level of oxidative stress in the host cells where bacteria survive. This observation nourishes the debate as whether the most appropriate strategy to cope with S. aureus intracellular infections would consist of trying to push persisters to a deep dormancy state from which wakening is improbable or, on the contrary, to prevent ROS-induced dormancy and force bacteria to maintain regular metabolism in order to restore their responsiveness to antibiotics. Importantly also, our data highlight the interest in single-cell analyses with conventional enumeration of CFU to quantify persisters and study host-pathogen interactions.
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Abstract
The spread of antibiotic-resistant Acinetobacter baumannii poses a significant threat to public health worldwide. This nosocomial bacterial pathogen can be associated with life-threatening infections, particularly in intensive care units. A. baumannii is mainly described as an extracellular pathogen with restricted survival within cells. This study shows that a subset of A. baumannii clinical isolates extensively multiply within nonphagocytic immortalized and primary cells without the induction of apoptosis and with bacterial clusters visible up to 48 h after infection. This phenotype was observed for the A. baumannii C4 strain associated with high mortality in a hospital outbreak and the A. baumannii ABC141 strain, which was isolated from the skin but was found to be hyperinvasive. Intracellular multiplication of these A. baumannii strains occurred within spacious single membrane-bound vacuoles, labeled with the lysosomal associate membrane protein (LAMP1). However, these compartments excluded lysotracker, an indicator of acidic pH, suggesting that A. baumannii can divert its trafficking away from the lysosomal degradative pathway. These compartments were also devoid of autophagy features. A high-content microscopy screen of 43 additional A. baumannii clinical isolates highlighted various phenotypes, and (i) the majority of isolates remained extracellular, (ii) a significant proportion was capable of invasion and limited persistence, and (iii) three more isolates efficiently multiplied within LAMP1-positive vacuoles, one of which was also hyperinvasive. These data identify an intracellular niche for specific A. baumannii clinical isolates that enables extensive multiplication in an environment protected from host immune responses and out of reach of many antibiotics. IMPORTANCE Multidrug-resistant Acinetobacter baumannii isolates are associated with significant morbidity and mortality in hospitals worldwide. Understanding their pathogenicity is critical for improving therapeutic management. Although A. baumannii can steadily adhere to surfaces and host cells, most bacteria remain extracellular. Recent studies have shown that a small proportion of bacteria can invade cells but present limited survival. We have found that some A. baumannii clinical isolates can establish a specialized intracellular niche that sustains extensive intracellular multiplication for a prolonged time without induction of cell death. We propose that this intracellular compartment allows A. baumannii to escape the cell’s normal degradative pathway, protecting bacteria from host immune responses and potentially hindering antibiotic accessibility. This may contribute to A. baumannii persistence, relapsing infections, and enhanced mortality in susceptible patients. A high-content microscopy-based screen confirmed that this pathogenicity trait is present in other clinical A. baumannii isolates. There is an urgent need for new antibiotics or alternative antimicrobial approaches, particularly to combat carbapenem-resistant A. baumannii. The discovery of an intracellular niche for this pathogen, as well as hyperinvasive isolates, may help guide the development of antimicrobial therapies and diagnostics in the future.
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33
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Plaunt AJ, Nguyen TL, Corboz MR, Malinin VS, Cipolla DC. Strategies to Overcome Biological Barriers Associated with Pulmonary Drug Delivery. Pharmaceutics 2022; 14:302. [PMID: 35214039 PMCID: PMC8880668 DOI: 10.3390/pharmaceutics14020302] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 01/20/2022] [Accepted: 01/23/2022] [Indexed: 02/01/2023] Open
Abstract
While the inhalation route has been used for millennia for pharmacologic effect, the biological barriers to treating lung disease created real challenges for the pharmaceutical industry until sophisticated device and formulation technologies emerged over the past fifty years. There are now several inhaled device technologies that enable delivery of therapeutics at high efficiency to the lung and avoid excessive deposition in the oropharyngeal region. Chemistry and formulation technologies have also emerged to prolong retention of drug at the active site by overcoming degradation and clearance mechanisms, or by reducing the rate of systemic absorption. These technologies have also been utilized to improve tolerability or to facilitate uptake within cells when there are intracellular targets. This paper describes the biological barriers and provides recent examples utilizing formulation technologies or drug chemistry modifications to overcome those barriers.
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Affiliation(s)
- Adam J. Plaunt
- Insmed Incorporated, Bridgewater, NJ 08807, USA; (T.L.N.); (M.R.C.); (V.S.M.); (D.C.C.)
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Dai T, Guo B, Qi G, Xu S, Zhou C, Bazan GC, Liu B. An AIEgen as an Intrinsic Antibacterial Agent for Light-Up Detection and Inactivation of Intracellular Gram-Positive Bacteria. Adv Healthc Mater 2021; 10:e2100885. [PMID: 34369089 DOI: 10.1002/adhm.202100885] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/22/2021] [Indexed: 12/22/2022]
Abstract
Infections caused by Gram-positive bacteria, especially those able to invade and survive in host cells, threaten human health severely. It is therefore highly desirable to develop therapeutics that can selectively target and kill intracellular Gram-positive pathogens with minimal toxicity to host cells. Herein, it is described that the aggregation-induced emission luminogen (AIEgen) TPEPy-Et, containing a positively charged pyridinium group and a hydrophobic tetraphenylethylene fragment, is effective for Gram-positive bacteria detection and elimination. The fluorescence of TPEPy-Et is greatly enhanced after incubation with Gram-positive bacteria, which can be used to detect and trace the bacteria in cells. TPEPy-Et also shows excellent killing effects against both extracellular and intracellular Gram-positive bacteria through a membrane depolarization mechanism. The luminescent antibacterial agent TPEPy-Et is thus promising for diagnosis and therapy against intracellular bacterial infection.
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Affiliation(s)
- Tianjiao Dai
- Integrative Sciences and Engineering Program NUS Graduate School National University of Singapore Singapore 119077 Singapore
- Department of Chemical and Biomolecular Engineering National University of Singapore Singapore 117585 Singapore
| | - Bingpeng Guo
- School of Chemistry and Chemical Engineering Beijing Institute of Technology Beijing 100081 China
| | - Guobin Qi
- Department of Chemical and Biomolecular Engineering National University of Singapore Singapore 117585 Singapore
| | - Shidang Xu
- Department of Chemical and Biomolecular Engineering National University of Singapore Singapore 117585 Singapore
| | - Cheng Zhou
- Department of Chemistry National University of Singapore Singapore 117543 Singapore
| | - Guillermo C. Bazan
- Department of Chemistry National University of Singapore Singapore 117543 Singapore
| | - Bin Liu
- Integrative Sciences and Engineering Program NUS Graduate School National University of Singapore Singapore 119077 Singapore
- Department of Chemical and Biomolecular Engineering National University of Singapore Singapore 117585 Singapore
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Compartmentalized Polymeric Nanoparticles Deliver Vancomycin in a pH-Responsive Manner. Pharmaceutics 2021; 13:pharmaceutics13121992. [PMID: 34959274 PMCID: PMC8709497 DOI: 10.3390/pharmaceutics13121992] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 11/06/2021] [Accepted: 11/11/2021] [Indexed: 12/31/2022] Open
Abstract
Vancomycin (VCM) is a last resort antibiotic in the treatment of severe Gram-positive infections. However, its administration is limited by several drawbacks such as: strong pH-dependent charge, tendency to aggregate, low bioavailability, and poor cellular uptake. These drawbacks were circumvented by engineering pH-responsive nanoparticles (NPs) capable to incorporate high VCM payload and deliver it specifically at slightly acidic pH corresponding to infection sites. Taking advantage of peculiar physicochemical properties of VCM, here we show how to incorporate VCM efficiently in biodegradable NPs made of poly(lactic-co-glycolic acid) and polylactic acid (co)polymers. The NPs were prepared by a simple and reproducible method, establishing strong electrostatic interactions between VCM and the (co)polymers’ end groups. VCM payloads reached up to 25 wt%. The drug loading mechanism was investigated by solid state nuclear magnetic resonance spectroscopy. The engineered NPs were characterized by a set of advanced physicochemical methods, which allowed examining their morphology, internal structures, and chemical composition on an individual NP basis. The compartmentalized structure of NPs was evidenced by cryogenic transmission electronic microscopy, whereas the chemical composition of the NPs’ top layers and core was obtained by electron microscopies associated with energy-dispersive X-ray spectroscopy. Noteworthy, atomic force microscopy coupled to infrared spectroscopy allowed mapping the drug location and gave semiquantitative information about the loadings of individual NPs. In addition, the NPs were stable upon storage and did not release the incorporated drug at neutral pH. Interestingly, a slight acidification of the medium induced a rapid VCM release. The compartmentalized NPs could find potential applications for controlled VCM release at an infected site with local acidic pH.
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Eckmann C, Tulkens PM. Current and future options for treating complicated skin and soft tissue infections: focus on fluoroquinolones and long-acting lipoglycopeptide antibiotics. J Antimicrob Chemother 2021; 76:iv9-iv22. [PMID: 34849999 PMCID: PMC8632788 DOI: 10.1093/jac/dkab351] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Bacterial skin and soft tissue infections are among the most common bacterial infections and constitute a major burden for patients and healthcare systems. Care is complicated by the variety of potential pathogens, some with resistance to previously effective antimicrobial agents, the wide spectrum of clinical presentations and the risk of progression to life-threatening forms. More-efficient care pathways are needed that can reduce hospital admissions and length of stay, while maintaining a high quality of care and adhering to antimicrobial stewardship principles. Several agents approved recently for treating acute bacterial skin and skin structure infections have characteristics that meet these requirements. We address the clinical and pharmacological characteristics of the fourth-generation fluoroquinolone delafloxacin, and the long-acting lipoglycopeptide agents dalbavancin and oritavancin.
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Affiliation(s)
- Christian Eckmann
- Department of General, Visceral and Thoracic Surgery, Klinikum Hannoversch-Muenden, Goettingen University, Germany
| | - Paul M Tulkens
- Cellular and Molecular Pharmacology, Louvain Drug Research Institute, Université catholique de Louvain (UCLouvain), Brussels, Belgium
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37
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Uropathogenic Escherichia coli Shows Antibiotic Tolerance and Growth Heterogeneity in an In Vitro Model of Intracellular Infection. Antimicrob Agents Chemother 2021; 65:e0146821. [PMID: 34570646 DOI: 10.1128/aac.01468-21] [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] [Indexed: 12/13/2022] Open
Abstract
Uropathogenic Escherichia coli (UPEC), the major causative agent of urinary tract infections, can invade different types of host cells. To compare the pharmacodynamic properties of antibiotics against intra- and extracellular UPEC, an in vitro model of intracellular infection was established in J774 mouse macrophages infected by the UPEC strain CFT073. We tested antibiotics commonly prescribed against urinary tract infections (gentamicin, ampicillin, nitrofurantoin, trimethoprim, sulfamethoxazole, and ciprofloxacin) and the investigational fluoroquinolone finafloxacin. The metabolic activity of individual bacteria was assessed by expressing the fluorescent reporter protein TIMERbac within CFT073. Concentration-response experiments revealed that all tested antibiotics were much less effective against intracellular bacteria than extracellular ones. Most antibiotics, except fluoroquinolones, were unable to reach a bactericidal effect intracellularly at clinically achievable concentrations. Ciprofloxacin and finafloxacin killed 99.9% of extracellular bacteria at concentrations around the MIC, while for intracellular bacteria, concentrations more than 100× over the MIC were required to achieve a bactericidal effect. Time-kill curves showed that finafloxacin was more rapidly bactericidal in acidic medium than at neutral pH, while the reverse observation was made for ciprofloxacin. Intracellularly, kill curves showed biphasic kinetics for both fluoroquinolones, suggesting the presence of drug-tolerant subpopulations. Flow cytometry analysis of TIMERbac fluorescence revealed a marked heterogeneity in intracellular growth of individual bacteria, suggesting that the presence of subpopulations reaching a state of metabolic dormancy was the main reason for increased antibiotic tolerance of intracellular UPEC.
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38
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Marro FC, Abad L, Blocker AJ, Laurent F, Josse J, Valour F. In vitro antibiotic activity against intraosteoblastic Staphylococcus aureus: a narrative review of the literature. J Antimicrob Chemother 2021; 76:3091-3102. [PMID: 34459881 PMCID: PMC8598303 DOI: 10.1093/jac/dkab301] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Staphylococcus aureus – a major aetiological agent of bone and joint infection (BJI) – is associated with a high risk of relapse and chronicity, in part due to its ability to invade and persist in non-professional phagocytic bone cells such as osteoblasts. This intracellular reservoir protects S. aureus from the action of the immune system and most antibiotics. To date, the choice of antimicrobial strategies for BJI treatment mostly relies on standard susceptibility testing, bone penetration of antibiotics and their ‘antibiofilm’ activity. Despite the role of intracellular persistent S. aureus in the development of chronic infection, the ability of antibiotics to target the S. aureus intraosteoblastic reservoir is not considered in therapeutic choices but might represent a key determinant of treatment outcome. This review provides an overview of the intracellular pharmacokinetics of antistaphylococcal drugs used in the treatment of BJI and of their ability to target intraosteoblastic S. aureus. Thirteen studies focusing on the intraosteoblastic activity of antibiotics against S. aureus were reviewed, all relying on in vitro models of osteoblast infection. Despite varying incubation times, multiplicities of infection, bacterial strains, and the types of infected cell lines, rifamycins and fluoroquinolones remain the two most potent antimicrobial classes for intraosteoblastic S. aureus eradication, consistent with clinical data showing a superiority of this combination therapy in S. aureus orthopaedic device-related infections.
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Affiliation(s)
- Florian C Marro
- CIRI-Centre International de Recherche en Infectiologie, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, Univ Lyon, F-69007 Lyon, France.,Evotec ID Lyon, In Vitro Biology, Infectious Diseases and Antibacterials Unit, Gerland, 69007 Lyon, France.,Université Claude Bernard Lyon 1, Lyon, France
| | - Lélia Abad
- CIRI-Centre International de Recherche en Infectiologie, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, Univ Lyon, F-69007 Lyon, France.,Université Claude Bernard Lyon 1, Lyon, France.,Laboratoire de bactériologie, Institut des Agents Infectieux, French National Reference Center for Staphylococci, Hospices Civils de Lyon, Lyon, France
| | - Ariel J Blocker
- Evotec ID Lyon, In Vitro Biology, Infectious Diseases and Antibacterials Unit, Gerland, 69007 Lyon, France
| | - Frédéric Laurent
- CIRI-Centre International de Recherche en Infectiologie, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, Univ Lyon, F-69007 Lyon, France.,Université Claude Bernard Lyon 1, Lyon, France.,Laboratoire de bactériologie, Institut des Agents Infectieux, French National Reference Center for Staphylococci, Hospices Civils de Lyon, Lyon, France.,Centre de Référence pour la prise en charge des Infections ostéo-articulaires complexes (CRIOAc) Lyon, Hospices Civils de Lyon, Lyon, France
| | - Jérôme Josse
- CIRI-Centre International de Recherche en Infectiologie, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, Univ Lyon, F-69007 Lyon, France.,Université Claude Bernard Lyon 1, Lyon, France.,Centre de Référence pour la prise en charge des Infections ostéo-articulaires complexes (CRIOAc) Lyon, Hospices Civils de Lyon, Lyon, France
| | - Florent Valour
- CIRI-Centre International de Recherche en Infectiologie, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, Ecole Normale Supérieure de Lyon, Univ Lyon, F-69007 Lyon, France.,Université Claude Bernard Lyon 1, Lyon, France.,Centre de Référence pour la prise en charge des Infections ostéo-articulaires complexes (CRIOAc) Lyon, Hospices Civils de Lyon, Lyon, France.,Service des maladies infectieuses et tropicales, Hospices Civils de Lyon, Lyon, France
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Ginsenoside 20(S)-Rh2 promotes cellular pharmacokinetics and intracellular antibacterial activity of levofloxacin against Staphylococcus aureus through drug efflux inhibition and subcellular stabilization. Acta Pharmacol Sin 2021; 42:1930-1941. [PMID: 34462563 PMCID: PMC8564512 DOI: 10.1038/s41401-021-00751-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 07/22/2021] [Indexed: 02/07/2023] Open
Abstract
Intracellular Staphylococcus aureus (S. aureus) often causes clinical failure and relapse after antibiotic treatment. We previously found that 20(S)-ginsenoside Rh2 [20(S)-Rh2] enhanced the therapeutic effect of quinolones in a mouse model of peritonitis, which we attributed to the increased concentrations of quinolones within bacteria. In this study, we investigated the enhancing effect of 20(S)-Rh2 on levofloxacin (LVF) from a perspective of intracellular bacteria. In S. aureus 25923-infected mice, coadministration of LVF (1.5 mg/kg, i.v.) and 20(S)-Rh2 (25, 50 mg/kg, i.g.) markedly increased the survival rate, and decreased intracellular bacteria counts accompanied by increased accumulation of LVF in peritoneal macrophages. In addition, 20(S)-Rh2 (1, 5, 10 μM) dose-dependently increased the uptake and accumulation of LVF in peritoneal macrophages from infected mice without drug treatment. In a model of S. aureus 25923-infected THP-1 macrophages, we showed that 20(S)-Rh2 (1, 5, 10 μM) dose-dependently enhanced the intracellular antibacterial activity of LVF. At the cellular level, 20(S)-Rh2 increased the intracellular accumulation of LVF by inhibiting P-gp and BCRP. PK-PD modeling revealed that 20(S)-Rh2 altered the properties of the cell but not LVF. At the subcellular level, 20(S)-Rh2 did not increase the distribution of LVF in lysosomes but exhibited a stronger sensitizing effect in acidic environments. Molecular dynamics (MD) simulations showed that 20(S)-Rh2 improved the stability of the DNA gyrase-LVF complex in lysosome-like acidic conditions. In conclusion, 20(S)-Rh2 promotes the cellular pharmacokinetics and intracellular antibacterial activities of LVF against S. aureus through efflux transporter inhibition and subcellular stabilization, which is beneficial for infection treatment.
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40
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Tanner L, Mashabela GT, Omollo CC, de Wet TJ, Parkinson CJ, Warner DF, Haynes RK, Wiesner L. Intracellular Accumulation of Novel and Clinically Used TB Drugs Potentiates Intracellular Synergy. Microbiol Spectr 2021; 9:e0043421. [PMID: 34585951 PMCID: PMC8557888 DOI: 10.1128/spectrum.00434-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 08/19/2021] [Indexed: 12/13/2022] Open
Abstract
The therapeutic repertoire for tuberculosis (TB) remains limited despite the existence of many TB drugs that are highly active in in vitro models and possess clinical utility. Underlying the lack of efficacy in vivo is the inability of TB drugs to penetrate microenvironments inhabited by the causative agent, Mycobacterium tuberculosis, including host alveolar macrophages. Here, we determined the ability of the phenoxazine PhX1 previously shown to be active against M. tuberculosis in vitro to differentially penetrate murine compartments, including plasma, epithelial lining fluid, and isolated epithelial lining fluid cells. We also investigated the extent of permeation into uninfected and M. tuberculosis-infected human macrophage-like Tamm-Horsfall protein 1 (THP-1) cells directly and by comparing to results obtained in vitro in synergy assays. Our data indicate that PhX1 (4,750 ± 127.2 ng/ml) penetrates more effectively into THP-1 cells than do the clinically used anti-TB agents, rifampin (3,050 ± 62.9 ng/ml), moxifloxacin (3,374 ± 48.7 ng/ml), bedaquiline (4,410 ± 190.9 ng/ml), and linezolid (770 ± 14.1 ng/ml). Compound efficacy in infected cells correlated with intracellular accumulation, reinforcing the perceived importance of intracellular penetration as a key drug property. Moreover, we detected synergies deriving from redox-stimulatory combinations of PhX1 or clofazimine with the novel prenylated amino-artemisinin WHN296. Finally, we used compound synergies to elucidate the relationship between compound intracellular accumulation and efficacy, with PhX1/WHN296 synergy levels shown to predict drug efficacy. Collectively, our data support the utility of the applied assays in identifying in vitro active compounds with the potential for clinical development. IMPORTANCE This study addresses the development of novel therapeutic compounds for the eventual treatment of drug-resistant tuberculosis. Tuberculosis continues to progress, with cases of Mycobacterium tuberculosis (M. tuberculosis) resistance to first-line medications increasing. We assess new combinations of drugs with both oxidant and redox properties coupled with a third partner drug, with the focus here being on the potentiation of M. tuberculosis-active combinations of compounds in the intracellular macrophage environment. Thus, we determined the ability of the phenoxazine PhX1, previously shown to be active against M. tuberculosis in vitro, to differentially penetrate murine compartments, including plasma, epithelial lining fluid, and isolated epithelial lining fluid cells. In addition, the extent of permeation into human macrophage-like THP-1 cells and H37Rv-infected THP-1 cells was measured via mass spectrometry and compared to in vitro two-dimensional synergy and subsequent intracellular efficacy. Collectively, our data indicate that development of new drugs will be facilitated using the methods described herein.
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Affiliation(s)
- Lloyd Tanner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Gabriel T. Mashabela
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Charles C. Omollo
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Timothy J. de Wet
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | | | - Digby F. Warner
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Wellcome Centre for Infectious Diseases Research in Africa, University of Cape Town, Cape Town, South Africa
| | - Richard K. Haynes
- Centre of Excellence for Pharmaceutical Sciences, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
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41
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Liu Y, Bai S, Wu T, Chen CC, Liu Y, Chao X, Bai Y. Dendronized Arm Snowflake Polymer as a Highly Branched Scaffold for Cellular Imaging and Delivery. Biomacromolecules 2021; 22:3791-3799. [PMID: 34339173 DOI: 10.1021/acs.biomac.1c00631] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Incorporation of branched structures is a major pathway to build macromolecules with desired three-dimensional (3D) structures, which are of high importance in the rational design of functional polymeric scaffolds. Dendrimers and hyperbranched polymers have been extensively studied for this purpose, but proper gain-of-function for these structures usually requires large enough molecular weights and a highly branched interior so that a spherical 3D core-shell architecture can be obtained, yet it is generally challenging to achieve precise control over the structure, high molecular weight, and high degree of branching (DoB) simultaneously. In this article, we present a set of snowflake-shaped star polymers with functional cores and dendronized arms, which ensure a high DoB and an overall globular conformation, thus facilitating the introduction of functional moieties onto the easily achieved scaffold without the need for high-generation dendrons. Using a polyglycerol dendron (PGD) as a proof of concept, we propose that this dendronized arm snowflake polymer (DASP) structure can serve as a better performing alternative to high-generation PGDs. DASPs with molecular weights of 750, 1220, 2120, and 3740 kDa were prepared with >85% yields in all cases, and we show that these DASPs have high encapsulating efficiency of Nile Red due to their high DoB and high biocompatibility due to their hydroxyl-rich nature after ketal removal, as well as high cell permeability that is molecular-weight-dependent. Introduced fluorophores such as fluorescein and difluoroboron 1,3-diphenylaminophenyl β-diketonate with suitable excitation wavelengths may turn the DASPs into stable, endosome-staining fluorophores with ultra-large Stokes shifts, narrowed emission bands, and suitability for long-term cellular tracing. Moreover, the scaffold can encapsulate antibiotic molecules and deliver them into phagolysosomes for efficient elimination of intracellular Staphylococcus aureus, which is insensitive toward many antibiotics but is a key target for the clinical success of methicillin-resistant Staphylococcus aureus infection treatment. Elimination of Staphylococcus aureus could be improved to >99.9% for chloramphenicol at 32 μg/mL with 450 μg/mL DASP.
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Affiliation(s)
- Yanhong Liu
- State Key Laboratory of Chem-/Bio-Sensing and Chemometrics, School of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Silei Bai
- State Key Laboratory of Chem-/Bio-Sensing and Chemometrics, School of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Tong Wu
- State Key Laboratory of Chem-/Bio-Sensing and Chemometrics, School of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Chun-Chi Chen
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, Hubei 430062, China
| | - Ying Liu
- State Key Laboratory of Chem-/Bio-Sensing and Chemometrics, School of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Xiangyu Chao
- State Key Laboratory of Chem-/Bio-Sensing and Chemometrics, School of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Yugang Bai
- State Key Laboratory of Chem-/Bio-Sensing and Chemometrics, School of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
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42
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Development and Preclinical Evaluation of New Inhaled Lipoglycopeptides for the Treatment of Persistent Pulmonary Methicillin-Resistant Staphylococcus aureus Infections. Antimicrob Agents Chemother 2021; 65:e0031621. [PMID: 33941518 PMCID: PMC8373216 DOI: 10.1128/aac.00316-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chronic pulmonary methicillin-resistant Staphylococcus aureus (MRSA) disease in cystic fibrosis (CF) has a high probability of recurrence following treatment with standard-of-care antibiotics and represents an area of unmet need associated with reduced life expectancy. We developed a lipoglycopeptide therapy customized for pulmonary delivery that not only demonstrates potent activity against planktonic MRSA, but also against protected colonies of MRSA in biofilms and within cells, the latter of which have been linked to clinical antibiotic failure. A library of next-generation potent lipoglycopeptides was synthesized with an emphasis on attaining superior pharmacokinetics (PK) and pharmacodynamics to similar compounds of their class. Our strategy focused on hydrophobic modification of vancomycin, where ester and amide functionality were included with carbonyl configuration and alkyl length as key variables. Candidates representative of each carbonyl attachment chemistry demonstrated potent activity in vitro, with several compounds being 30 to 60 times more potent than vancomycin. Selected compounds were advanced into in vivo nose-only inhalation PK evaluations in rats, where RV94, a potent lipoglycopeptide that utilizes an inverted amide linker to attach a 10-carbon chain to vancomycin, demonstrated the most favorable lung residence time after inhalation. Further in vitro evaluation of RV94 showed superior activity to vancomycin against an expanded panel of Gram-positive organisms, cellular accumulation and efficacy against intracellular MRSA, and MRSA biofilm killing. Moreover, in vivo efficacy of inhaled nebulized RV94 in a 48 h acute model of pulmonary MRSA (USA300) infection in neutropenic rats demonstrated statistically significant antibacterial activity that was superior to inhaled vancomycin.
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43
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Rowe SE, Beam JE, Conlon BP. Recalcitrant Staphylococcus aureus Infections: Obstacles and Solutions. Infect Immun 2021; 89:e00694-20. [PMID: 33526569 PMCID: PMC8090968 DOI: 10.1128/iai.00694-20] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Antibiotic treatment failure of Staphylococcus aureus infections is very common. In addition to genetically encoded mechanisms of antibiotic resistance, numerous additional factors limit the efficacy of antibiotics in vivo Identifying and removing the barriers to antibiotic efficacy are of major importance, as even if new antibiotics become available, they will likely face the same barriers to efficacy as their predecessors. One major obstacle to antibiotic efficacy is the proficiency of S. aureus to enter a physiological state that is incompatible with antibiotic killing. Multiple pathways leading to antibiotic tolerance and the formation of tolerant subpopulations called persister cells have been described for S. aureus Additionally, S. aureus is a versatile pathogen that can infect numerous tissues and invade a variety of cell types, of which some are poorly penetrable to antibiotics. It is therefore unlikely that there will be a single solution to the problem of recalcitrant S. aureus infection. Instead, specific approaches may be required for targeting tolerant cells within different niches, be it through direct targeting of persister cells, sensitization of persisters to conventional antibiotics, improved penetration of antibiotics to particular niches, or any combination thereof. Here, we examine two well-described reservoirs of antibiotic-tolerant S. aureus, the biofilm and the macrophage, the barriers these environments present to antibiotic efficacy, and potential solutions to the problem.
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Affiliation(s)
- Sarah E Rowe
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Jenna E Beam
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Brian P Conlon
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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44
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Kong FYS, Horner P, Unemo M, Hocking JS. Pharmacokinetic considerations regarding the treatment of bacterial sexually transmitted infections with azithromycin: a review. J Antimicrob Chemother 2021; 74:1157-1166. [PMID: 30649333 DOI: 10.1093/jac/dky548] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Rates of bacterial sexually transmitted infections (STIs) continue to rise, demanding treatments to be highly effective. However, curing infections faces significant challenges due to antimicrobial resistance in Neisseria gonorrhoeae and Mycoplasma genitalium and especially treating STIs at extragenital sites, particularly rectal chlamydia and oropharyngeal gonorrhoea. As no new antimicrobials are entering the market, clinicians must optimize the currently available treatments, but robust data are lacking on how the properties or pharmacokinetics of antimicrobials can be used to inform STI treatment regimens to improve treatment outcomes. This paper provides a detailed overview of the published pharmacokinetics of antimicrobials used to treat STIs and how factors related to the drug (tissue distribution, protein binding and t½), human (pH, inflammation, site of infection, drug side effects and sexual practices) and organism (organism load and antimicrobial resistance) can affect treatment outcomes. As azithromycin is commonly used to treat chlamydia, gonorrhoea and M. genitalium infections, and its pharmacokinetics are well studied, it is the main focus of this review. Suggestions are also provided on possible dosing regimens when using extended and/or higher doses of azithromycin, which appropriately balance efficacy and side effects. The paper also emphasizes the limitations of currently published pharmacokinetic studies including oropharyngeal gonococcal infections, where very limited data exist around ceftriaxone pharmacokinetics and its use in combination with azithromycin. In future, the different anatomical sites of infections may require alternative therapeutic approaches.
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Affiliation(s)
- Fabian Yuh Shiong Kong
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
| | - Patrick Horner
- Population Health Sciences, University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK.,National Institute for Health Research Health Protection Research Unit in Evaluation of Interventions, University of Bristol, Bristol, UK
| | - Magnus Unemo
- WHO Collaborating Centre for Gonorrhoea and Other STIs, National Reference Laboratory for Sexually Transmitted Infections, Department of Laboratory Medicine, Microbiology, Örebro University, Örebro, Sweden
| | - Jane S Hocking
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
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45
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The Polyaminoisoprenyl Potentiator NV716 Revives Old Disused Antibiotics against Intracellular Forms of Infection by Pseudomonas aeruginosa. Antimicrob Agents Chemother 2021; 65:AAC.02028-20. [PMID: 33318000 DOI: 10.1128/aac.02028-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 12/05/2020] [Indexed: 12/24/2022] Open
Abstract
Active efflux confers intrinsic resistance to multiple antibiotics in Pseudomonas aeruginosa, including old disused molecules. Beside resistance, intracellular survival is another reason for failure to eradicate bacteria with antibiotics. We evaluated the capacity of polyaminoisoprenyl potentiators (designed as efflux pump inhibitors [EPIs]) NV716 and NV731 compared to PAβN to restore the activity of disused antibiotics (doxycycline, chloramphenicol [substrates for efflux], and rifampin [nonsubstrate]) in comparison with ciprofloxacin against intracellular P. aeruginosa (strains with variable efflux levels) in THP-1 monocytes exposed over 24 h to antibiotics alone (0.003 to 100× MIC) or combined with EPIs. Pharmacodynamic parameters (apparent static concentrations [C s] and maximal relative efficacy [E max]) were calculated using the Hill equation of concentration-response curves. PAβN and NV731 moderately reduced (0 to 4 doubling dilutions) antibiotic MICs but did not affect their intracellular activity. NV716 markedly reduced (1 to 16 doubling dilutions) the MIC of all antibiotics (substrates or not for efflux; strains expressing efflux or not); it also improved their relative potency and maximal efficacy (i.e., lower C s; more negative E max) intracellularly. In parallel, NV716 reduced the persister fraction in stationary cultures when combined with ciprofloxacin. In contrast to PAβN and NV731, which act only as EPIs against extracellular bacteria, NV716 can resensitize P. aeruginosa to antibiotics whether they are substrates or not for efflux, both extracellularly and intracellularly. This suggests a complex mode of action that goes beyond a simple inhibition of efflux to reduce bacterial persistence. NV716 appears to be a useful adjuvant, including to disused antibiotics with low antipseudomonal activity, to improve their activity, including against intracellular P. aeruginosa.
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Lallemand EA, Zemirline C, Toutain PL, Bousquet-Melou A, Ferran AA, Boullier S. Dynamic interactions between cephalexin and macrophages on different Staphylococcus aureus inoculum sizes: a tripartite in vitro model. BMC Vet Res 2021; 17:23. [PMID: 33413376 PMCID: PMC7792187 DOI: 10.1186/s12917-021-02746-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 01/01/2021] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND The bactericidal activity of an antimicrobial drug is generally assessed by in vitro bacterial time-kill experiments which do not include any components of the immune system, even though the innate immunity, the primary host defence, is probably able to kill a large proportion of pathogenic bacteria in immunocompetent patients. We developed an in vitro tripartite model to investigate the joint action of C57Bl/6 murine bone-marrow-derived macrophages and cephalexin on the killing of Staphylococcus aureus. RESULTS By assessing the bactericidal effects on four bacterial inoculum sizes, we showed that macrophages can cooperate with cephalexin on inoculum sizes lower than 106 CFU/mL and conversely, protect S. aureus from cephalexin killing activity at the highest inoculum size. Cell analysis by flow cytometry revealed that macrophages were rapidly overwhelmed when exposed to large inoculums. Increasing the initial inoculum size from 105 to 107 CFU/mL increased macrophage death and decreased their ability to kill bacteria from six hours after exposure to bacteria. The addition of cephalexin at 16-fold MIC to 105 and 106 CFU/mL inoculums allowed the macrophages to survive and to maintain their bactericidal activity as if they were exposed to a small bacterial inoculum. However, with the highest inoculum size of 107 CFU/mL, the final bacterial counts in the supernatant were higher with macrophages plus cephalexin than with cephalexin alone. CONCLUSIONS These results suggest that if the bacterial population at the infectious site is low, as potentially encountered in the early stage of infection or at the end of an antimicrobial treatment, the observed cooperation between macrophages and cephalexin could facilitate its control.
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Affiliation(s)
- Elodie Anne Lallemand
- InTheRes, Université de Toulouse, INRAE, ENVT, 23 chemin des Capelles, BP 87614, 31 076, Toulouse Cedex 3, France.
| | - Claudine Zemirline
- Ceva Santé Animale, Laval Campus, Allée de la communication, 53950, Louverné, France
| | - Pierre-Louis Toutain
- InTheRes, Université de Toulouse, INRAE, ENVT, 23 chemin des Capelles, BP 87614, 31 076, Toulouse Cedex 3, France
- The Royal Veterinary College, Hawkshead Campus, Hatfield, Herts, AL9 7TA, UK
| | - Alain Bousquet-Melou
- InTheRes, Université de Toulouse, INRAE, ENVT, 23 chemin des Capelles, BP 87614, 31 076, Toulouse Cedex 3, France
| | - Aude A Ferran
- InTheRes, Université de Toulouse, INRAE, ENVT, 23 chemin des Capelles, BP 87614, 31 076, Toulouse Cedex 3, France
| | - Séverine Boullier
- InTheRes, Université de Toulouse, INRAE, ENVT, 23 chemin des Capelles, BP 87614, 31 076, Toulouse Cedex 3, France
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Hook EW, Newman L, Drusano G, Evans S, Handsfield HH, Jerse AE, Kong FYS, Lee JY, Taylor SN, Deal C. Development of New Antimicrobials for Urogenital Gonorrhea Therapy: Clinical Trial Design Considerations. Clin Infect Dis 2021; 70:1495-1500. [PMID: 31538646 DOI: 10.1093/cid/ciz899] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 09/13/2019] [Indexed: 12/31/2022] Open
Abstract
Gonorrhea remains a major public health challenge, and current recommendations for gonorrhea treatment are threatened by evolving antimicrobial resistance and a diminished pipeline for new antibiotics. Evaluations of potential new treatments for gonorrhea currently make limited use of new understanding of the pharmacokinetic and pharmacodynamic contributors to effective therapy, the prevention of antimicrobial resistance, and newer designs for clinical trials. They are hampered by the requirement to utilize combination ceftriaxone/azithromycin therapy as the comparator regimen in noninferiority trials designed to seek an indication for gonorrhea therapy. Evolving gonococcal epidemiology and clinical trial design constraints hinder the enrollment of those populations at the greatest risk for gonorrhea (adolescents, women, and persons infected with antibiotic-resistant Neisseria gonorrhoeae). This article summarizes a recent meeting on the evaluation process for antimicrobials for urogenital gonorrhea treatment and encourages the consideration of new designs for the evaluation of gonorrhea therapy.
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Affiliation(s)
- Edward W Hook
- University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Lori Newman
- National Institute for Allergy and Infectious Diseases, Rockville, Maryland, USA
| | - George Drusano
- Institute for Therapeutic Innovation, University of Florida, Lake Nona, Florida, USA
| | - Scott Evans
- Milken Institute School of Public Health George Washington University, Washington, DC, USA
| | | | - Ann E Jerse
- Uniformed Services University, Bethesda, Maryland, USA
| | - Fabian Y S Kong
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia
| | | | | | - Carolyn Deal
- National Institute for Allergy and Infectious Diseases, Rockville, Maryland, USA
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48
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Peyrusson F, Nguyen TK, Buyck JM, Lemaire S, Wang G, Seral C, Tulkens PM, Van Bambeke F. In Vitro Models for the Study of the Intracellular Activity of Antibiotics. Methods Mol Biol 2021; 2357:239-251. [PMID: 34590263 DOI: 10.1007/978-1-0716-1621-5_16] [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] [Indexed: 12/14/2022]
Abstract
Intracellular bacteria are poorly responsive to antibiotic treatment. Pharmacological studies are thus needed to determine the antibiotics which are the most potent or effective against intracellular bacteria as well as to explore the reasons for poor bacterial responsiveness. An in vitro pharmacodynamic model is described, consisting of (1) phagocytosis of preopsonized bacteria by eukaryotic cells, (2) elimination of noninternalized bacteria with gentamicin, (3) incubation of infected cells with antibiotics, and (4) determination of surviving bacteria by viable cell counting and normalization of the counts based on sample protein content. The use of strains expressing fluorescent proteins under the control of an inducible promoter allows to follow intracellular bacterial division at the individual level and therefore to monitor bacterial persisters that do not multiply anymore.
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Affiliation(s)
- Frédéric Peyrusson
- Pharmacologie Cellulaire et Moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Tiep K Nguyen
- Pharmacologie Cellulaire et Moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Julien M Buyck
- Pharmacologie Cellulaire et Moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.,INSERM U1070 "Pharmacology of Anti-infective Agents", Université de Poitiers, Poitiers, France
| | - Sandrine Lemaire
- Pharmacologie Cellulaire et Moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.,GSK Biologicals, Rixensart, Belgium
| | - Gang Wang
- Pharmacologie Cellulaire et Moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Cristina Seral
- Pharmacologie Cellulaire et Moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.,Department of Microbiology, Hospital Clínico Universitario Lozano Blesa, Zaragoza, Spain
| | - Paul M Tulkens
- Pharmacologie Cellulaire et Moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Françoise Van Bambeke
- Pharmacologie Cellulaire et Moléculaire, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.
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49
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Jiang Y, Han M, Bo Y, Feng Y, Li W, Wu JR, Song Z, Zhao Z, Tan Z, Chen Y, Xue T, Fu Z, Kuo SH, Lau GW, Luijten E, Cheng J. "Metaphilic" Cell-Penetrating Polypeptide-Vancomycin Conjugate Efficiently Eradicates Intracellular Bacteria via a Dual Mechanism. ACS CENTRAL SCIENCE 2020; 6:2267-2276. [PMID: 33376787 PMCID: PMC7760462 DOI: 10.1021/acscentsci.0c00893] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Indexed: 05/02/2023]
Abstract
Infections by intracellular pathogens are difficult to treat because of the poor accessibility of antibiotics to the pathogens encased by host cell membranes. As such, a strategy that can improve the membrane permeability of antibiotics would significantly increase their efficiency against the intracellular pathogens. Here, we report the design of an adaptive, metaphilic cell-penetrating polypeptide (CPP)-antibiotic conjugate (VPP-G) that can effectively eradicate the intracellular bacteria both in vitro and in vivo. VPP-G was synthesized by attaching vancomycin to a highly membrane-penetrative guanidinium-functionalized metaphilic CPP. VPP-G effectively kills not only extracellular but also far more challenging intracellular pathogens, such as S. aureus, methicillin-resistant S. aureus, and vancomycin-resistant Enterococci. VPP-G enters the host cell via a unique metaphilic membrane penetration mechanism and kills intracellular bacteria through disruption of both cell wall biosynthesis and membrane integrity. This dual antimicrobial mechanism of VPP-G prevents bacteria from developing drug resistance and could also potentially kill dormant intracellular bacteria. VPP-G effectively eradicates MRSA in vivo, significantly outperforming vancomycin, which represents one of the most effective intracellular antibacterial agents reported so far. This strategy can be easily adapted to develop other conjugates against different intracellular pathogens by attaching different antibiotics to these highly membrane-penetrative metaphilic CPPs.
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Affiliation(s)
- Yunjiang Jiang
- Department
of Materials Science and Engineering, Beckman Institute for Advanced
Science and Technology, Department of Bioegineering, Department of Chemistry, Department of Pathobiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Ming Han
- Applied Physics Graduate Program, Department of Materials Science and Engineering,Department of Engineering
Sciences and Applied Mathematics, Department of Chemistry, Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, United States
- Chicago
Materials Research Center, University of
Chicago, Chicago, Illinois 60637, United States
| | - Yang Bo
- Department
of Materials Science and Engineering, Beckman Institute for Advanced
Science and Technology, Department of Bioegineering, Department of Chemistry, Department of Pathobiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Yujun Feng
- Department
of Materials Science and Engineering, Beckman Institute for Advanced
Science and Technology, Department of Bioegineering, Department of Chemistry, Department of Pathobiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Wenming Li
- Department
of Materials Science and Engineering, Beckman Institute for Advanced
Science and Technology, Department of Bioegineering, Department of Chemistry, Department of Pathobiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Jason Ren Wu
- Department
of Materials Science and Engineering, Beckman Institute for Advanced
Science and Technology, Department of Bioegineering, Department of Chemistry, Department of Pathobiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Ziyuan Song
- Department
of Materials Science and Engineering, Beckman Institute for Advanced
Science and Technology, Department of Bioegineering, Department of Chemistry, Department of Pathobiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Zihao Zhao
- Department
of Materials Science and Engineering, Beckman Institute for Advanced
Science and Technology, Department of Bioegineering, Department of Chemistry, Department of Pathobiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Zhengzhong Tan
- Department
of Materials Science and Engineering, Beckman Institute for Advanced
Science and Technology, Department of Bioegineering, Department of Chemistry, Department of Pathobiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Yingying Chen
- Department
of Materials Science and Engineering, Beckman Institute for Advanced
Science and Technology, Department of Bioegineering, Department of Chemistry, Department of Pathobiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Tianrui Xue
- Department
of Materials Science and Engineering, Beckman Institute for Advanced
Science and Technology, Department of Bioegineering, Department of Chemistry, Department of Pathobiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Zihuan Fu
- Department
of Materials Science and Engineering, Beckman Institute for Advanced
Science and Technology, Department of Bioegineering, Department of Chemistry, Department of Pathobiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Shanny Hsuan Kuo
- Department
of Materials Science and Engineering, Beckman Institute for Advanced
Science and Technology, Department of Bioegineering, Department of Chemistry, Department of Pathobiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Gee W. Lau
- Department
of Materials Science and Engineering, Beckman Institute for Advanced
Science and Technology, Department of Bioegineering, Department of Chemistry, Department of Pathobiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Erik Luijten
- Applied Physics Graduate Program, Department of Materials Science and Engineering,Department of Engineering
Sciences and Applied Mathematics, Department of Chemistry, Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, United States
| | - Jianjun Cheng
- Department
of Materials Science and Engineering, Beckman Institute for Advanced
Science and Technology, Department of Bioegineering, Department of Chemistry, Department of Pathobiology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
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50
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Alder KD, Lee I, Munger AM, Kwon HK, Morris MT, Cahill SV, Back J, Yu KE, Lee FY. Intracellular Staphylococcus aureus in bone and joint infections: A mechanism of disease recurrence, inflammation, and bone and cartilage destruction. Bone 2020; 141:115568. [PMID: 32745687 DOI: 10.1016/j.bone.2020.115568] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 07/19/2020] [Accepted: 07/26/2020] [Indexed: 02/06/2023]
Abstract
Bone and joint infections are devastating afflictions. Although medical interventions and advents have improved their care, bone and joint infections still portend dismal outcomes. Indeed, bone and joint infections are associated with extremely high mortality and morbidity rates and, generally, occur secondary to the aggressive pathogen Staphylococcus aureus. The consequences of bone and joint infections are further compounded by the fact that although they are aggressively treated, they frequently recur and result in massive bone and articular cartilage loss. Here, we review the literature and chronicle the fact that the fundamental cellular components of the musculoskeletal system can be internally infected with Staphylococcus aureus, which explains the ready recurrence of bone and joint infections even after extensive administration of antibiotic therapy and debridement and offer potential treatment solutions for further study. Moreover, we review the ramifications of intracellular infection and expound that the massive bone and articular cartilage loss is caused by the sustained proinflammatory state induced by infection and offer potential combination therapies for further study to protect bone and cartilage.
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Affiliation(s)
- Kareme D Alder
- Department of Orthopædics & Rehabilitation, Yale University, School of Medicine, New Haven, CT, USA; Yale University School of Medicine, Department of Orthopaedics and Rehabilitation, 330 Cedar St, TMP 523, PO Box 208071, New Haven, CT 06520-8071, USA.
| | - Inkyu Lee
- Department of Orthopædics & Rehabilitation, Yale University, School of Medicine, New Haven, CT, USA; Department of Life Science, Chung-Ang University, Seoul, Republic of Korea; Yale University School of Medicine, Department of Orthopaedics and Rehabilitation, 330 Cedar St, TMP 523, PO Box 208071, New Haven, CT 06520-8071, USA.
| | - Alana M Munger
- Department of Orthopædics & Rehabilitation, Yale University, School of Medicine, New Haven, CT, USA; Yale University School of Medicine, Department of Orthopaedics and Rehabilitation, 330 Cedar St, TMP 523, PO Box 208071, New Haven, CT 06520-8071, USA.
| | - Hyuk-Kwon Kwon
- Department of Orthopædics & Rehabilitation, Yale University, School of Medicine, New Haven, CT, USA; Yale University School of Medicine, Department of Orthopaedics and Rehabilitation, 330 Cedar St, TMP 523, PO Box 208071, New Haven, CT 06520-8071, USA.
| | - Montana T Morris
- Department of Orthopædics & Rehabilitation, Yale University, School of Medicine, New Haven, CT, USA; Yale University School of Medicine, Department of Orthopaedics and Rehabilitation, 330 Cedar St, TMP 523, PO Box 208071, New Haven, CT 06520-8071, USA.
| | - Sean V Cahill
- Department of Orthopædics & Rehabilitation, Yale University, School of Medicine, New Haven, CT, USA; Yale University School of Medicine, Department of Orthopaedics and Rehabilitation, 330 Cedar St, TMP 523, PO Box 208071, New Haven, CT 06520-8071, USA.
| | - JungHo Back
- Department of Orthopædics & Rehabilitation, Yale University, School of Medicine, New Haven, CT, USA; Yale University School of Medicine, Department of Orthopaedics and Rehabilitation, 330 Cedar St, TMP 523, PO Box 208071, New Haven, CT 06520-8071, USA.
| | - Kristin E Yu
- Department of Orthopædics & Rehabilitation, Yale University, School of Medicine, New Haven, CT, USA; Yale University School of Medicine, Department of Orthopaedics and Rehabilitation, 330 Cedar St, TMP 523, PO Box 208071, New Haven, CT 06520-8071, USA.
| | - Francis Y Lee
- Department of Orthopædics & Rehabilitation, Yale University, School of Medicine, New Haven, CT, USA; Yale University School of Medicine, Department of Orthopaedics and Rehabilitation, 330 Cedar St, TMP 523, PO Box 208071, New Haven, CT 06520-8071, USA.
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