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Dolan SK, Duong AT, Whiteley M. Convergent evolution in toxin detection and resistance provides evidence for conserved bacterial-fungal interactions. Proc Natl Acad Sci U S A 2024; 121:e2304382121. [PMID: 39088389 DOI: 10.1073/pnas.2304382121] [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: 03/16/2023] [Accepted: 06/12/2024] [Indexed: 08/03/2024] Open
Abstract
Microbes rarely exist in isolation and instead form complex polymicrobial communities. As a result, microbes have developed intricate offensive and defensive strategies that enhance their fitness in these complex communities. Thus, identifying and understanding the molecular mechanisms controlling polymicrobial interactions is critical for understanding the function of microbial communities. In this study, we show that the gram-negative opportunistic human pathogen Pseudomonas aeruginosa, which frequently causes infection alongside a plethora of other microbes including fungi, encodes a genetic network which can detect and defend against gliotoxin, a potent, disulfide-containing antimicrobial produced by the ubiquitous filamentous fungus Aspergillus fumigatus. We show that gliotoxin exposure disrupts P. aeruginosa zinc homeostasis, leading to transcriptional activation of a gene encoding a previously uncharacterized dithiol oxidase (herein named as DnoP), which detoxifies gliotoxin and structurally related toxins. Despite sharing little homology to the A. fumigatus gliotoxin resistance protein (GliT), the enzymatic mechanism of DnoP from P. aeruginosa appears to be identical that used by A. fumigatus. Thus, DnoP and its transcriptional induction by low zinc represent a rare example of both convergent evolution of toxin defense and environmental cue sensing across kingdoms. Collectively, these data provide compelling evidence that P. aeruginosa has evolved to survive exposure to an A. fumigatus disulfide-containing toxin in the natural environment.
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Affiliation(s)
- Stephen K Dolan
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30310
- Department of Genetics and Biochemistry, Eukaryotic Pathogens Innovation Center, Clemson University, Clemson, SC 29634
- Emory-Children's Cystic Fibrosis Center, Atlanta, GA 30310
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA 30310
| | - Ashley T Duong
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30310
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA 30310
| | - Marvin Whiteley
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30310
- Emory-Children's Cystic Fibrosis Center, Atlanta, GA 30310
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA 30310
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2
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Sánchez-Peña A, Winans JB, Nadell CD, Limoli DH. Pseudomonas aeruginosa surface motility and invasion into competing communities enhance interspecies antagonism. mBio 2024:e0095624. [PMID: 39105585 DOI: 10.1128/mbio.00956-24] [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: 04/02/2024] [Accepted: 07/02/2024] [Indexed: 08/07/2024] Open
Abstract
Chronic polymicrobial infections involving Pseudomonas aeruginosa and Staphylococcus aureus are prevalent, difficult to eradicate, and associated with poor health outcomes. Therefore, understanding interactions between these pathogens is important to inform improved treatment development. We previously demonstrated that P. aeruginosa is attracted to S. aureus using type IV pili (TFP)-mediated chemotaxis, but the impact of attraction on S. aureus growth and physiology remained unknown. Using live single-cell confocal imaging to visualize microcolony structure, spatial organization, and survival of S. aureus during coculture, we found that interspecies chemotaxis provides P. aeruginosa a competitive advantage by promoting invasion into and disruption of S. aureus microcolonies. This behavior renders S. aureus susceptible to P. aeruginosa antimicrobials. Conversely, in the absence of TFP motility, P. aeruginosa cells exhibit reduced invasion of S. aureus colonies. Instead, P. aeruginosa builds a cellular barrier adjacent to S. aureus and secretes diffusible, bacteriostatic antimicrobials like 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO) into the S. aureus colonies. Reduced invasion leads to the formation of denser and thicker S. aureus colonies with increased HQNO-mediated lactic acid fermentation, a physiological change that could complicate treatment strategies. Finally, we show that P. aeruginosa motility modifications of spatial structure enhance competition against S. aureus. Overall, these studies expand our understanding of how P. aeruginosa TFP-mediated interspecies chemotaxis facilitates polymicrobial interactions, highlighting the importance of spatial positioning in mixed-species communities. IMPORTANCE The polymicrobial nature of many chronic infections makes their eradication challenging. Particularly, coisolation of Pseudomonas aeruginosa and Staphylococcus aureus from airways of people with cystic fibrosis and chronic wound infections is common and associated with severe clinical outcomes. The complex interplay between these pathogens is not fully understood, highlighting the need for continued research to improve management of chronic infections. Our study unveils that P. aeruginosa is attracted to S. aureus, invades into neighboring colonies, and secretes anti-staphylococcal factors into the interior of the colony. Upon inhibition of P. aeruginosa motility and thus invasion, S. aureus colony architecture changes dramatically, whereby S. aureus is protected from P. aeruginosa antagonism and responds through physiological alterations that may further hamper treatment. These studies reinforce accumulating evidence that spatial structuring can dictate community resilience and reveal that motility and chemotaxis are critical drivers of interspecies competition.
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Affiliation(s)
- Andrea Sánchez-Peña
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - James B Winans
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA
| | - Carey D Nadell
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA
| | - Dominique H Limoli
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
- Department of Biology, Indiana University, Bloomington, Indiana, USA
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3
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Park J, Xiang Z, Liu Y, Li CH, Chen C, Nagaraj H, Nguyen T, Nabawy A, Koo H, Rotello VM. Surface-Charge Tuned Polymeric Nanoemulsions for Carvacrol Delivery in Interkingdom Biofilms. ACS APPLIED MATERIALS & INTERFACES 2024; 16:37613-37622. [PMID: 39007413 DOI: 10.1021/acsami.4c06618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Biofilms, intricate microbial communities entrenched in extracellular polymeric substance (EPS) matrices, pose formidable challenges in infectious disease treatment, especially in the context of interkingdom biofilms prevalent in the oral environment. This study investigates the potential of carvacrol-loaded biodegradable nanoemulsions (NEs) with systematically varied surface charges─cationic guanidinium (GMT-NE) and anionic carboxylate (CMT-NE). Zeta potentials of +25 mV (GMT-NE) and -33 mV (CMT-NE) underscore successful nanoemulsion fabrication (∼250 nm). Fluorescent labeling and dynamic tracking across three dimensions expose GMT-NE's superior diffusion into oral biofilms, yielding a robust antimicrobial effect with 99.99% killing for both streptococcal and Candida species and marked reductions in bacterial cell viability compared to CMT-NE (∼4-log reduction). Oral mucosa tissue cultures affirm the biocompatibility of both NEs with no morphological or structural changes, showcasing their potential for combating intractable biofilm infections in oral environment. This study advances our understanding of NE surface charges and their interactions within interkingdom biofilms, providing insights crucial for addressing complex infections involving bacteria and fungi in the demanding oral context.
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Affiliation(s)
- Jungmi Park
- Department of Chemistry, University of Massachusetts Amherst, 710 North Pleasant Street, Amherst, Massachusetts 01003, United States
| | - Zhenting Xiang
- Biofilm Research Laboratories, Levy Center for Oral Health, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Orthodontics, School of Dental Medicine, University of Pennsylvania, 240 S 40th Street, Philadelphia, Pennsylvania 19104, United States
| | - Yuan Liu
- Biofilm Research Laboratories, Levy Center for Oral Health, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Preventive and Restorative Sciences, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Cheng-Hsuan Li
- Department of Chemistry, University of Massachusetts Amherst, 710 North Pleasant Street, Amherst, Massachusetts 01003, United States
| | - Chider Chen
- Department of Oral and Maxillofacial Surgery and Pharmacology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Harini Nagaraj
- Department of Chemistry, University of Massachusetts Amherst, 710 North Pleasant Street, Amherst, Massachusetts 01003, United States
| | - Tiffany Nguyen
- Department of Chemistry, University of Massachusetts Amherst, 710 North Pleasant Street, Amherst, Massachusetts 01003, United States
| | - Ahmed Nabawy
- Department of Chemistry, University of Massachusetts Amherst, 710 North Pleasant Street, Amherst, Massachusetts 01003, United States
| | - Hyun Koo
- Biofilm Research Laboratories, Levy Center for Oral Health, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Orthodontics, School of Dental Medicine, University of Pennsylvania, 240 S 40th Street, Philadelphia, Pennsylvania 19104, United States
- Center for Innovation and Precision Dentistry, School of Dental Medicine, School of Engineering and Applied Sciences, University of Pennsylvania, 240 S 40th Street, Philadelphia, Pennsylvania 19104, United States
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, 210 S 33rd Street, Philadelphia, Pennsylvania 19104, United States
| | - Vincent M Rotello
- Department of Chemistry, University of Massachusetts Amherst, 710 North Pleasant Street, Amherst, Massachusetts 01003, United States
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Horowitz RI, Fallon J, Freeman PR. Combining Double-Dose and High-Dose Pulsed Dapsone Combination Therapy for Chronic Lyme Disease/Post-Treatment Lyme Disease Syndrome and Co-Infections, Including Bartonella: A Report of 3 Cases and a Literature Review. Microorganisms 2024; 12:909. [PMID: 38792737 PMCID: PMC11124288 DOI: 10.3390/microorganisms12050909] [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: 04/03/2024] [Accepted: 04/22/2024] [Indexed: 05/26/2024] Open
Abstract
Three patients with relapsing and remitting borreliosis, babesiosis, and bartonellosis, despite extended anti-infective therapy, were prescribed double-dose dapsone combination therapy (DDDCT) for 8 weeks, followed by one or several two-week courses of pulsed high-dose dapsone combination therapy (HDDCT). We discuss these patients' cases to illustrate three important variables required for long-term remission. First, diagnosing and treating active co-infections, including Babesia and Bartonella were important. Babesia required rotations of multiple anti-malarial drug combinations and herbal therapies, and Bartonella required one or several 6-day HDDCT pulses to achieve clinical remission. Second, all prior oral, intramuscular (IM), and/or intravenous (IV) antibiotics used for chronic Lyme disease (CLD)/post-treatment Lyme disease syndrome (PTLDS), irrespective of the length of administration, were inferior in efficacy to short-term pulsed biofilm/persister drug combination therapy i.e., dapsone, rifampin, methylene blue, and pyrazinamide, which improved resistant fatigue, pain, headaches, insomnia, and neuropsychiatric symptoms. Lastly, addressing multiple factors on the 16-point multiple systemic infectious disease syndrome (MSIDS) model was important in achieving remission. In conclusion, DDDCT with one or several 6-7-day pulses of HDDCT, while addressing abnormalities on the 16-point MSIDS map, could represent a novel effective clinical and anti-infective strategy in CLD/PTLDS and associated co-infections including Bartonella.
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Affiliation(s)
- Richard I. Horowitz
- New York State Department of Health Tick-Borne Working Group, Albany, NY 12224, USA
- Hudson Valley Healing Arts Center, Hyde Park, NY 12538, USA; (J.F.); (P.R.F.)
| | - John Fallon
- Hudson Valley Healing Arts Center, Hyde Park, NY 12538, USA; (J.F.); (P.R.F.)
| | - Phyllis R. Freeman
- Hudson Valley Healing Arts Center, Hyde Park, NY 12538, USA; (J.F.); (P.R.F.)
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5
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Manyahi J, Joachim A, Msafiri F, Migiro M, Mwingwa A, Kasubi M, Naburi H, Majigo MV. Polymicrobial bloodstream infections a risk factor for mortality in neonates at the national hospital, Tanzania: A case-control study. PLoS One 2024; 19:e0302076. [PMID: 38625965 PMCID: PMC11020784 DOI: 10.1371/journal.pone.0302076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 03/26/2024] [Indexed: 04/18/2024] Open
Abstract
BACKGROUND Polymicrobial bloodstream infections (BSI) are difficult to treat since empiric antibiotics treatment are frequently less effective against multiple pathogens. The study aimed to compare outcomes in patients with polymicrobial and monomicrobial BSIs. METHODS The study was a retrospective case-control design conducted at Muhimbili National Hospital for data processed between July 2021 and June 2022. Cases were patients with polymicrobial BSI, and controls had monomicrobial BSI. Each case was matched to three controls by age, admitting ward, and duration of admission. Logistic regression was performed to determine independent risk factors for in-hospital and 30-day mortality. RESULTS Fifty patients with polymicrobial BSI and 150 with monomicrobial BSI were compared: the two arms had no significant differences in sex and comorbidities. The most frequent bacteria in polymicrobial BSI were Klebsiella pneumoniae 17% (17/100) and Enterobacter species 15% (15/100). In monomicrobial BSI, S. aureus 17.33% (26/150), Klebsiella pneumoniae 16.67% (25/150), and Acinetobacter species 15% (15/150) were more prevalent. Overall, isolates were frequently resistant to multiple antibiotics tested, and 52% (130/250) were multidrug resistance. The 30-day and in-hospital mortality were 33.5% (67/200) and 36% (72/200), respectively. On multivariable analysis, polymicrobial BSIs were independent risk factors for both in-hospital mortality (aOR 2.37, 95%CI 1.20-4.69, p = 0.01) and 30-day mortality (aOR 2.05, 95%CI 1.03-4.08), p = 0.04). In sub-analyses involving only neonates, polymicrobial BSI was an independent risk factor for both 30-day mortality (aOR 3.13, 95%CI 1.07-9.10, p = 0.04) and in-hospital mortality (aOR 5.08, 95%CI 1.60-16.14, p = 0.006). Overall, the median length of hospital stay post-BSIs was numerically longer in patients with polymicrobial BSIs. CONCLUSION Overall, polymicrobial BSI was a significant risk for mortality. Patients with polymicrobial BSI stay longer at the hospital than those with monomicrobial BSI. These findings call for clinicians to be more aggressive in managing polymicrobial BSI.
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Affiliation(s)
- Joel Manyahi
- Department of Microbiology and Immunology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Agricola Joachim
- Department of Microbiology and Immunology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Frank Msafiri
- Department of Microbiology and Immunology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Mary Migiro
- Department of Microbiology and Immunology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Anthon Mwingwa
- Department of Microbiology and Immunology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Mabula Kasubi
- Muhimbili National Hospital, Dar es Salaam, Tanzania
| | - Helga Naburi
- Department of Pediatrics and Child Health, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Mtebe Venance Majigo
- Department of Microbiology and Immunology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
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6
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Sánchez-Peña A, Winans JB, Nadell CD, Limoli DH. Pseudomonas aeruginosa surface motility and invasion into competing communities enhances interspecies antagonism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.03.588010. [PMID: 38617332 PMCID: PMC11014535 DOI: 10.1101/2024.04.03.588010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Chronic polymicrobial infections involving Pseudomonas aeruginosa and Staphylococcus aureus are prevalent, difficult to eradicate, and associated with poor health outcomes. Therefore, understanding interactions between these pathogens is important to inform improved treatment development. We previously demonstrated that P. aeruginosa is attracted to S. aureus using type IV pili-mediated chemotaxis, but the impact of attraction on S. aureus growth and physiology remained unknown. Using live single-cell confocal imaging to visualize microcolony structure, spatial organization, and survival of S. aureus during coculture, we found that interspecies chemotaxis provides P. aeruginosa a competitive advantage by promoting invasion into and disruption of S. aureus microcolonies. This behavior renders S. aureus susceptible to P. aeruginosa antimicrobials. Conversely, in the absence of type IV pilus motility, P. aeruginosa cells exhibit reduced invasion of S. aureus colonies. Instead, P. aeruginosa builds a cellular barrier adjacent to S. aureus and secretes diffusible, bacteriostatic antimicrobials like 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO) into the S. aureus colonies. P. aeruginosa reduced invasion leads to the formation of denser and thicker S. aureus colonies with significantly increased HQNO-mediated lactic acid fermentation, a physiological change that could complicate the effective treatment of infections. Finally, we show that P. aeruginosa motility modifications of spatial structure enhance competition against S. aureus. Overall, these studies build on our understanding of how P. aeruginosa type IV pili-mediated interspecies chemotaxis mediates polymicrobial interactions, highlighting the importance of spatial positioning in mixed-species communities.
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Affiliation(s)
- Andrea Sánchez-Peña
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - James B Winans
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA
| | - Carey D Nadell
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA
| | - Dominique H Limoli
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
- Department of Biology, Indiana University, Bloomington, Indiana, USA
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7
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Kamal S, Varshney K, Uayan DJ, Tenorio BG, Pillay P, Sava ST. Risk Factors and Clinical Characteristics of Pandrug-Resistant Pseudomonas aeruginosa. Cureus 2024; 16:e58114. [PMID: 38738125 PMCID: PMC11088816 DOI: 10.7759/cureus.58114] [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: 04/12/2024] [Indexed: 05/14/2024] Open
Abstract
The emergence of increasingly resistant strains of Pseudomonas aeruginosa is a great public health concern. Understanding the risk factors and clinical characteristics of patients with pandrug-resistant P. aeruginosa (PDR-PA) can help inform clinicians in creating guidelines for both prevention and management. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, this scoping review retrieved existing literature on PDR-PA by searching PubMed, SCOPUS, Embase, Web of Science, and CINAHL databases. From the 21 studies that satisfied the inclusion criteria,1,059 P. aeruginosa samples were identified, and 161, or 15.2% of the isolates were found to have pandrug resistance. Furthermore, our review suggests that PDR-PA was largely hospital-acquired, and patients suffering from burn injuries and chronic lung diseases had a higher risk of colonization than other hospitalized individuals. In five out of the 21 studies, administration of the antibiotic colistin emerged to be the preferred therapeutic strategy. With regards to concurrent infections, Acinetobacter and Klebsiella species were found to occur most frequently with PDR-PA, suggesting mutualistic interactions that enable further antimicrobial resistance. In conclusion, this review showed the prevalence of PDR-PA and outlined the demographic and clinical profile of affected patients. Further research is needed to investigate the transmission and outcomes of PDR-PA infections and to find potential therapeutic strategies.
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Affiliation(s)
- Shahed Kamal
- Internal Medicine, Northern Hospital Epping, Melbourne, AUS
| | - Karan Varshney
- Public Health, School of Medicine, Deakin University, Waurn Ponds, AUS
| | - Danielle J Uayan
- Medicine, Ateneo School of Medicine and Public Health, Manila, PHL
| | - Bettina G Tenorio
- Medicine, Ateneo School of Medicine and Public Health, Philippines, Manila, PHL
| | - Preshon Pillay
- Faculty of Medicine and Dentistry, University of Alberta, Alberta, CAN
| | - Sergiu T Sava
- Medicine, School of Medicine, Deakin University, Geelong, AUS
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8
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Lories B, Belpaire TER, Smeets B, Steenackers HP. Competition quenching strategies reduce antibiotic tolerance in polymicrobial biofilms. NPJ Biofilms Microbiomes 2024; 10:23. [PMID: 38503782 PMCID: PMC10951329 DOI: 10.1038/s41522-024-00489-6] [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: 10/20/2022] [Accepted: 02/20/2024] [Indexed: 03/21/2024] Open
Abstract
Bacteria typically live in dense communities where they are surrounded by other species and compete for a limited amount of resources. These competitive interactions can induce defensive responses that also protect against antimicrobials, potentially complicating the antimicrobial treatment of pathogens residing in polymicrobial consortia. Therefore, we evaluate the potential of alternative antivirulence strategies that quench this response to competition. We test three competition quenching approaches: (i) interference with the attack mechanism of surrounding competitors, (ii) inhibition of the stress response systems that detect competition, and (iii) reduction of the overall level of competition in the community by lowering the population density. We show that either strategy can prevent the induction of antimicrobial tolerance of Salmonella Typhimurium in response to competitors. Competition quenching strategies can thus reduce tolerance of pathogens residing in polymicrobial communities and could contribute to the improved eradication of these pathogens via traditional methods.
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Affiliation(s)
- Bram Lories
- Department of Microbial and Molecular Systems, Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Leuven, Belgium
| | - Tom E R Belpaire
- Department of Microbial and Molecular Systems, Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Leuven, Belgium
- Division of Mechatronics, Biostatistics, and Sensors (MeBioS), Department of Biosystems, KU Leuven, Leuven, Belgium
| | - Bart Smeets
- Division of Mechatronics, Biostatistics, and Sensors (MeBioS), Department of Biosystems, KU Leuven, Leuven, Belgium
| | - Hans P Steenackers
- Department of Microbial and Molecular Systems, Centre of Microbial and Plant Genetics (CMPG), KU Leuven, Leuven, Belgium.
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9
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Costa FMS, Granja A, Pérez RL, Warner IM, Reis S, Passos MLC, Saraiva MLMFS. Fluoroquinolone-Based Organic Salts (GUMBOS) with Antibacterial Potential. Int J Mol Sci 2023; 24:15714. [PMID: 37958698 PMCID: PMC10650486 DOI: 10.3390/ijms242115714] [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: 09/29/2023] [Revised: 10/25/2023] [Accepted: 10/25/2023] [Indexed: 11/15/2023] Open
Abstract
Antimicrobial resistance is a silent pandemic considered a public health concern worldwide. Strategic therapies are needed to replace antibacterials that are now ineffective. One approach entails the use of well-known antibacterials along with adjuvants that possess non-antibiotic properties but can extend the lifespan and enhance the effectiveness of the treatment, while also improving the suppression of resistance. In this regard, a group of uniform materials based on organic salts (GUMBOS) presents an alternative to this problem allowing the combination of antibacterials with adjuvants. Fluoroquinolones are a family of antibacterials used to treat respiratory and urinary tract infections with broad-spectrum activity. Ciprofloxacin and moxifloxacin-based GUMBOS were synthesized via anion exchange reactions with lithium and sodium salts. Structural characterization, thermal stability and octanol/water partition ratios were evaluated. The antibacterial profiles of most GUMBOS were comparable to their cationic counterparts when tested against Gram-positive S. aureus and Gram-negative E. coli, except for deoxycholate anion, which demonstrated the least effective antibacterial activity. Additionally, some GUMBOS were less cytotoxic to L929 fibroblast cells and non-hemolytic to red blood cells. Therefore, these agents exhibit promise as an alternative approach to combining drugs for treating infections caused by resistant bacteria.
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Affiliation(s)
- Fábio M. S. Costa
- LAQV, REQUIMTE, Laboratory of Applied Pharmacy, Department of Chemical Sciences, Faculty of Pharmacy, Porto University, Rua de Jorge Viterbo Ferreira, 4050-313 Porto, Portugal; (F.M.S.C.); (A.G.); (S.R.)
| | - Andreia Granja
- LAQV, REQUIMTE, Laboratory of Applied Pharmacy, Department of Chemical Sciences, Faculty of Pharmacy, Porto University, Rua de Jorge Viterbo Ferreira, 4050-313 Porto, Portugal; (F.M.S.C.); (A.G.); (S.R.)
| | - Rocío L. Pérez
- Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA; (R.L.P.); (I.M.W.)
- Department of Chemistry and Biochemistry, Georgia Southern University, Statesboro, GA 30458, USA
| | - Isiah M. Warner
- Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA; (R.L.P.); (I.M.W.)
- Department of Chemistry, Cincinnati University, Cincinnati, OH 45221, USA
| | - Salette Reis
- LAQV, REQUIMTE, Laboratory of Applied Pharmacy, Department of Chemical Sciences, Faculty of Pharmacy, Porto University, Rua de Jorge Viterbo Ferreira, 4050-313 Porto, Portugal; (F.M.S.C.); (A.G.); (S.R.)
| | - Marieta L. C. Passos
- LAQV, REQUIMTE, Laboratory of Applied Pharmacy, Department of Chemical Sciences, Faculty of Pharmacy, Porto University, Rua de Jorge Viterbo Ferreira, 4050-313 Porto, Portugal; (F.M.S.C.); (A.G.); (S.R.)
| | - M. Lúcia M. F. S. Saraiva
- LAQV, REQUIMTE, Laboratory of Applied Pharmacy, Department of Chemical Sciences, Faculty of Pharmacy, Porto University, Rua de Jorge Viterbo Ferreira, 4050-313 Porto, Portugal; (F.M.S.C.); (A.G.); (S.R.)
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10
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Black C, Al Mahmud H, Howle V, Wilson S, Smith AC, Wakeman CA. Development of a Polymicrobial Checkerboard Assay as a Tool for Determining Combinatorial Antibiotic Effectiveness in Polymicrobial Communities. Antibiotics (Basel) 2023; 12:1207. [PMID: 37508303 PMCID: PMC10376321 DOI: 10.3390/antibiotics12071207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/13/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
The checkerboard assay is a well-established tool used to determine the antimicrobial effects of two compounds in combination. Usually, data collected from the checkerboard assay use visible turbidity and optical density as a readout. While helpful in traditional checkerboard assays, these measurements become less useful in a polymicrobial context as they do not enable assessment of the drug effects on the individual members of the community. The methodology described herein allows for the determination of cell viability through selective and differential plating of each individual species in a community while retaining much of the high-throughput nature of a turbidity-based analysis and requiring no specialized equipment. This methodology further improves turbidity-based measurements by providing a distinction between bacteriostatic versus bactericidal concentrations of antibiotics. Herein, we use this method to demonstrate that the clinically used antibiotic combination of ceftazidime and gentamicin works synergistically against Pseudomonas aeruginosa in monoculture but antagonistically in a polymicrobial culture also containing Acinetobacter baumannii, Staphylococcus aureus, and Enterococcus faecalis, highlighting the fundamental importance of this methodology in improving clinical practices. We propose that this method could be implemented in clinical microbiology laboratories with minimal impact on the overall time for diagnosis.
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Affiliation(s)
- Caroline Black
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA; (C.B.)
| | - Hafij Al Mahmud
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA; (C.B.)
| | - Victoria Howle
- Department of Mathematics and Statistics, Texas Tech University, Lubbock, TX 79409, USA
| | - Sabrina Wilson
- Department of Honors Studies, Texas Tech University, Lubbock, TX 79409, USA
| | - Allie C. Smith
- Department of Honors Studies, Texas Tech University, Lubbock, TX 79409, USA
| | - Catherine A. Wakeman
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA; (C.B.)
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11
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Bose S, Singh DV, Adhya TK, Acharya N. Escherichia coli, but Not Staphylococcus aureus, Functions as a Chelating Agent That Exhibits Antifungal Activity against the Pathogenic Yeast Candida albicans. J Fungi (Basel) 2023; 9:jof9030286. [PMID: 36983454 PMCID: PMC10057578 DOI: 10.3390/jof9030286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/04/2023] [Accepted: 01/11/2023] [Indexed: 02/24/2023] Open
Abstract
Humans are colonized by diverse populations of microbes. Infections by Candida albicans, an opportunistic fungal pathogen, are a result of imbalances in the gut microbial ecosystem and are due to the suppressed immunity of the host. Here, we explored the potential effects of the polymicrobial interactions of C. albicans with Staphylococcus aureus, a Gram-positive bacterium, and Escherichia coli, a Gram-negative bacterium, in dual and triple in vitro culture systems on their respective growth, morphology, and biofilms. We found that S. aureus promoted the fungal growth and hyphal transition of C. albicans through cell-to-cell contacts; contrarily, both the cell and cell-free culture filtrate of E. coli inhibited fungal growth. A yet to be identified secretory metabolite of E. coli functionally mimicked EDTA and EGTA to exhibit antifungal activity. These findings suggested that E. coli, but not S. aureus, functions as a chelating agent and that E. coli plays a dominant role in regulating excessive growth and, potentially, the commensalism of C. albicans. Using animal models of systemic candidiasis, we found that the E. coli cell-free filtrate suppressed the virulence of C. albicans. In general, this study unraveled a significant antimicrobial activity and a potential role in the nutritional immunity of E. coli, and further determining the underlying processes behind the E. coli–C. albicans interaction could provide critical information in understanding the pathogenicity of C. albicans.
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Affiliation(s)
- Swagata Bose
- Department of Infectious Disease Biology, Institute of Life Sciences, Bhubaneswar 751023, India
- KIIT School of Biotechnology, Bhubaneswar 751021, India
| | - Durg Vijai Singh
- Department of Biotechnology, School of Earth, Biological and Environmental Sciences, Central University of South Bihar, Gaya 824236, India
| | | | - Narottam Acharya
- Department of Infectious Disease Biology, Institute of Life Sciences, Bhubaneswar 751023, India
- Correspondence: ; Tel.: +91-674-230-4278; Fax: +91-674-230-0728
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12
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AtbFinder Diagnostic Test System Improves Optimal Selection of Antibiotic Therapy in Persons with Cystic Fibrosis. J Clin Microbiol 2023; 61:e0155822. [PMID: 36602344 PMCID: PMC9879114 DOI: 10.1128/jcm.01558-22] [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] [Indexed: 01/06/2023] Open
Abstract
Cystic fibrosis (CF) is characterized by mutations of CFTR that lead to increased viscous secretions, bacterial colonization, and recurrent infections. Chronic Pseudomonas aeruginosa infection in persons with CF is associated with progressive and accelerated lung function decline despite aggressive antibiotic treatment. We report the management of respiratory infections in persons with CF with antibiotic therapy that was based on the recommendations of AtbFinder, a novel, rapid, culture-based diagnostic test system that employs a novel paradigm of antibiotic selection. AtbFinder mimics bacterial interactions with antibiotics at concentrations that can be achieved in affected tissues or organs and models conditions of interbacterial interactions within polymicrobial biofilms. This open-label, single-arm, investigator-initiated clinical study was designed to identify the efficacy of antibiotics selected using AtbFinder in persons with CF. Microbiological and clinical parameters were assessed following the change of antibiotic therapy to antibiotics selected with AtbFinder between January 2016 and December 2018 and retrospectively compared with clinical data collected between January 2013 and December 2015. We enrolled 35 persons with CF (33 with chronic P. aeruginosa colonization). Antibiotics selected using AtbFinder resulted in clearance of P. aeruginosa in 81.8% of subsequent cultures, decreased pulmonary exacerbations from 1.21 per patient per annum to 0, and an increase in predicted percent predicted forced expiratory volume in 1 s up to 28.4% from baseline. The number of systemic antibiotic courses used in patients after switching to the AtbFinder-selected therapy was reduced from 355 to 178. These findings describe the superiority of antibiotic regimens selected with AtbFinder compared with routine antimicrobial susceptibility testing.
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13
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Perikleous EP, Gkentzi D, Bertzouanis A, Paraskakis E, Sovtic A, Fouzas S. Antibiotic Resistance in Patients with Cystic Fibrosis: Past, Present, and Future. Antibiotics (Basel) 2023; 12:antibiotics12020217. [PMID: 36830128 PMCID: PMC9951886 DOI: 10.3390/antibiotics12020217] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/15/2023] [Accepted: 01/19/2023] [Indexed: 01/22/2023] Open
Abstract
Patients with cystic fibrosis (CF) are repeatedly exposed to antibiotics, especially during the pulmonary exacerbations of the disease. However, the available therapeutic strategies are frequently inadequate to eradicate the involved pathogens and most importantly, facilitate the development of antimicrobial resistance (AMR). The evaluation of AMR is demanding; conventional culture-based susceptibility-testing techniques cannot account for the lung microenvironment and/or the adaptive mechanisms developed by the pathogens, such as biofilm formation. Moreover, features linked to modified pharmaco-kinetics and pulmonary parenchyma penetration make the dosing of antibiotics even more challenging. In this review, we present the existing knowledge regarding AMR in CF, we shortly review the existing therapeutic strategies, and we discuss the future directions of antimicrobial stewardship. Due to the increasing difficulty in eradicating strains that develop AMR, the appropriate management should rely on targeting the underlying resistance mechanisms; thus, the interest in novel, molecular-based diagnostic tools, such as metagenomic sequencing and next-generation transcriptomics, has increased exponentially. Moreover, since the development of new antibiotics has a slow pace, the design of effective treatment strategies to eradicate persistent infections represents an urgency that requires consorted work. In this regard, both the management and monitoring of antibiotics usage are obligatory and more relevant than ever.
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Affiliation(s)
| | - Despoina Gkentzi
- Department of Pediatrics, University of Patras Medical School, 26504 Patras, Greece
| | - Aris Bertzouanis
- Department of Pediatrics, University of Patras Medical School, 26504 Patras, Greece
- Pediatric Respiratory Unit, University Hospital of Patras, 26504 Patras, Greece
| | - Emmanouil Paraskakis
- Pediatric Respiratory Unit, Department of Pediatrics, University of Crete, 71500 Heraklion, Greece
| | - Aleksandar Sovtic
- School of Medicine, University of Belgrade, 11000 Belgrade, Serbia
- Department of Pulmonology, Mother and Child Health Institute of Serbia, 11070 Belgrade, Serbia
| | - Sotirios Fouzas
- Department of Pediatrics, University of Patras Medical School, 26504 Patras, Greece
- Pediatric Respiratory Unit, University Hospital of Patras, 26504 Patras, Greece
- Correspondence: ; Tel.: +30-2610-999980
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14
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Increasing the Efficacy of Treatment of Staphylococcus aureus- Candida albicans Mixed Infections with Myrtenol. Antibiotics (Basel) 2022; 11:antibiotics11121743. [PMID: 36551400 PMCID: PMC9774912 DOI: 10.3390/antibiotics11121743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 11/27/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022] Open
Abstract
Infectious diseases caused by various nosocomial microorganisms affect worldwide both immunocompromised and relatively healthy persons. Bacteria and fungi have different tools to evade antimicrobials, such as hydrolysis damaging the drug, efflux systems, and the formation of biofilm that significantly complicates the treatment of the infection. Here, we show that myrtenol potentiates the antimicrobial and biofilm-preventing activity of conventional drugs against S. aureus and C. albicans mono- and dual-species cultures. In our study, the two optical isomers, (-)-myrtenol and (+)-myrtenol, have been tested as either antibacterials, antifungals, or enhancers of conventional drugs. (+)-Myrtenol demonstrated a synergistic effect with amikacin, fluconazole, and benzalkonium chloride on 64-81% of the clinical isolates of S. aureus and C. albicans, including MRSA and fluconazole-resistant fungi, while (-)-myrtenol increased the properties of amikacin and fluconazole to repress biofilm formation in half of the S. aureus and C. albicans isolates. Furthermore, myrtenol was able to potentiate benzalkonium chloride up to sixteen-fold against planktonic cells in an S. aureus-C. albicans mixed culture and repressed the adhesion of S. aureus. The mechanism of both (-)-myrtenol and (+)-myrtenol synergy with conventional drugs was apparently driven by membrane damage since the treatment with both terpenes led to a significant drop in membrane potential similar to the action of benzalkonium chloride. Thus, due to the low toxicity of myrtenol, it seems to be a promising agent to increase the efficiency of the treatment of infections caused by bacteria and be fungi of the genus Candida as well as mixed fungal-bacterial infections, including resistant strains.
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15
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Overcoming Antibiotic Resistance with Novel Paradigms of Antibiotic Selection. Microorganisms 2022; 10:microorganisms10122383. [PMID: 36557636 PMCID: PMC9781420 DOI: 10.3390/microorganisms10122383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 11/25/2022] [Accepted: 11/28/2022] [Indexed: 12/04/2022] Open
Abstract
Conventional antimicrobial susceptibility tests, including phenotypic and genotypic methods, are insufficiently accurate and frequently fail to identify effective antibiotics. These methods predominantly select therapies based on the antibiotic response of only the lead bacterial pathogen within pure bacterial culture. However, this neglects the fact that, in the majority of human infections, the lead bacterial pathogens are present as a part of multispecies communities that modulate the response of these lead pathogens to antibiotics and that multiple pathogens can contribute to the infection simultaneously. This discrepancy is a major cause of the failure of antimicrobial susceptibility tests to detect antibiotics that are effective in vivo. This review article provides a comprehensive overview of the factors that are missed by conventional antimicrobial susceptibility tests and it explains how accounting for these methods can aid the development of novel diagnostic approaches.
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16
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M. S. Costa F, Lúcia M. F. S. Saraiva M, L. C. Passos M. Ionic Liquids and Organic Salts with Antimicrobial Activity as a Strategy Against Resistant Microorganisms. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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17
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Ch'ng JH, Muthu M, Chong KKL, Wong JJ, Tan CAZ, Koh ZJS, Lopez D, Matysik A, Nair ZJ, Barkham T, Wang Y, Kline KA. Heme cross-feeding can augment Staphylococcus aureus and Enterococcus faecalis dual species biofilms. THE ISME JOURNAL 2022; 16:2015-2026. [PMID: 35589966 PMCID: PMC9296619 DOI: 10.1038/s41396-022-01248-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 04/18/2022] [Accepted: 04/29/2022] [Indexed: 12/17/2022]
Abstract
The contribution of biofilms to virulence and as a barrier to treatment is well-established for Staphylococcus aureus and Enterococcus faecalis, both nosocomial pathogens frequently isolated from biofilm-associated infections. Despite frequent co-isolation, their interactions in biofilms have not been well-characterized. We report that in combination, these two species can give rise to augmented biofilms biomass that is dependent on the activation of E. faecalis aerobic respiration. In E. faecalis, respiration requires both exogenous heme to activate the cydAB-encoded heme-dependent cytochrome bd, and the availability of O2. We determined that the ABC transporter encoded by cydDC contributes to heme import. In dual species biofilms, S. aureus provides the heme to activate E. faecalis respiration. S. aureus mutants deficient in heme biosynthesis were unable to augment biofilms whereas heme alone is sufficient to augment E. faecalis mono-species biofilms. Our results demonstrate that S. aureus-derived heme, likely in the form of released hemoproteins, promotes E. faecalis biofilm formation, and that E. faecalis gelatinase activity facilitates heme extraction from hemoproteins. This interspecies interaction and metabolic cross-feeding may explain the frequent co-occurrence of these microbes in biofilm-associated infections.
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Affiliation(s)
- Jun-Hong Ch'ng
- Department of Microbiology and Immunology, National University of Singapore, Singapore, Singapore. .,Department of Surgery Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore. .,Infectious Disease Translational Research Program, National University Health System, Singapore, Singapore. .,Singapore Centre for Environmental Life Sciences Engineering, National University of Singapore, Singapore, Singapore.
| | - Mugil Muthu
- Department of Microbiology and Immunology, National University of Singapore, Singapore, Singapore.,Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Kelvin K L Chong
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.,Nanyang Technological University Institute for Health Technologies, Interdisciplinary Graduate School, Nanyang Technological University, Singapore, Singapore
| | - Jun Jie Wong
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.,Singapore Centre for Environmental Life Sciences Engineering, Interdisciplinary Graduate Program, Nanyang Technological University, Singapore, Singapore
| | - Casandra A Z Tan
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore.,Singapore Centre for Environmental Life Sciences Engineering, Interdisciplinary Graduate Program, Nanyang Technological University, Singapore, Singapore
| | - Zachary J S Koh
- Department of Microbiology and Immunology, National University of Singapore, Singapore, Singapore
| | - Daniel Lopez
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Artur Matysik
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Zeus J Nair
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Timothy Barkham
- Department of Microbiology and Immunology, National University of Singapore, Singapore, Singapore.,Department of Laboratory Medicine, Tan Tock Seng Hospital, Singapore, Singapore
| | - Yulan Wang
- Singapore Phenome Center, Lee Kong Chian School of Medicine, Nanyang Technological University, Nanyang, Singapore
| | - Kimberly A Kline
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore. .,School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
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Competition for Iron during Polymicrobial Infections May Increase Antifungal Drug Susceptibility-How Will It Impact Treatment Options? Infect Immun 2022; 90:e0005722. [PMID: 35289634 DOI: 10.1128/iai.00057-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Interaction between microbes may influence antimicrobial susceptibility of one or more of the microbes, with studies pointing to increased resistance in these scenarios. Hattab et al. provided a novel perspective by identifying synergism between fluconazole and bacterial antagonism in the context of Candida albicans-Pseudomonas aeruginosa co-infection. Further research is required to translate these findings to the clinical setting, especially in the era of increasing antifungal resistance.
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19
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Pohl CH. Recent Advances and Opportunities in the Study of Candida albicans Polymicrobial Biofilms. Front Cell Infect Microbiol 2022; 12:836379. [PMID: 35252039 PMCID: PMC8894716 DOI: 10.3389/fcimb.2022.836379] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 01/26/2022] [Indexed: 01/11/2023] Open
Abstract
It is well known that the opportunistic pathogenic yeast, Candida albicans, can form polymicrobial biofilms with a variety of bacteria, both in vitro and in vivo, and that these polymicrobial biofilms can impact the course and management of disease. Although specific interactions are often described as either synergistic or antagonistic, this may be an oversimplification. Polymicrobial biofilms are complex two-way interacting communities, regulated by inter-domain (inter-kingdom) signaling and various molecular mechanisms. This review article will highlight advances over the last six years (2016-2021) regarding the unique biology of polymicrobial biofilms formed by C. albicans and bacteria, including regulation of their formation. In addition, some of the consequences of these interactions, such as the influence of co-existence on antimicrobial susceptibility and virulence, will be discussed. Since the aim of this knowledge is to inform possible alternative treatment options, recent studies on the discovery of novel anti-biofilm compounds will also be included. Throughout, an attempt will be made to identify ongoing challenges in this area.
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20
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Systems Biology and Bile Acid Signalling in Microbiome-Host Interactions in the Cystic Fibrosis Lung. Antibiotics (Basel) 2021; 10:antibiotics10070766. [PMID: 34202495 PMCID: PMC8300688 DOI: 10.3390/antibiotics10070766] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/14/2021] [Accepted: 06/21/2021] [Indexed: 12/16/2022] Open
Abstract
The study of the respiratory microbiota has revealed that the lungs of healthy and diseased individuals harbour distinct microbial communities. Imbalances in these communities can contribute to the pathogenesis of lung disease. How these imbalances occur and establish is largely unknown. This review is focused on the genetically inherited condition of Cystic Fibrosis (CF). Understanding the microbial and host-related factors that govern the establishment of chronic CF lung inflammation and pathogen colonisation is essential. Specifically, dissecting the interplay in the inflammation–pathogen–host axis. Bile acids are important host derived and microbially modified signal molecules that have been detected in CF lungs. These bile acids are associated with inflammation and restructuring of the lung microbiota linked to chronicity. This community remodelling involves a switch in the lung microbiota from a high biodiversity/low pathogen state to a low biodiversity/pathogen-dominated state. Bile acids are particularly associated with the dominance of Proteobacterial pathogens. The ability of bile acids to impact directly on both the lung microbiota and the host response offers a unifying principle underpinning the pathogenesis of CF. The modulating role of bile acids in lung microbiota dysbiosis and inflammation could offer new potential targets for designing innovative therapeutic approaches for respiratory disease.
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