1
|
Larsen TG, Samaniego Castruita JA, Worning P, Westh H, Bartels MD. Within-host genomic evolution of methicillin-resistant Staphylococcus aureus in long-term carriers. Appl Microbiol Biotechnol 2024; 108:95. [PMID: 38212970 PMCID: PMC10784349 DOI: 10.1007/s00253-023-12932-3] [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: 08/01/2023] [Revised: 11/14/2023] [Accepted: 11/27/2023] [Indexed: 01/13/2024]
Abstract
Assessing the genomic evolution of Staphylococcus aureus can help us understand how the bacteria adapt to its environment. In this study, we aimed to assess the mutation rate within 144 methicillin-resistant Staphylococcus aureus (MRSA) carriers with a carriage time from 4 to 11 years, including some carriers who belonged to the same households. We found that 23 of the 144 individuals had completely different MRSA types over time and were therefore not long-term carriers of the same MRSA. From the remaining 121 individuals, we performed whole-genome sequencing (WGS) on 424 isolates and then compared these pairwise using core genome multilocus sequence typing (cgMLST) and single-nucleotide polymorphism (SNP) analyses. We found a median within-host mutation rate in long-term MRSA carriers of 4.9 (3.4-6.9) SNPs/genome/year and 2.7 (1.8-4.2) allelic differences/genome/year, when excluding presumed recombination. Furthermore, we stratified the cohort into subgroups and found no significant difference between the median mutation rate of members of households, individuals with presumed continued exposure, e.g., from travel and persons without known continued exposure. Finally, we found that SNPs occurred at random within the genes in our cohort. KEY POINTS: • Median mutation rate within long-term MRSA carriers of 4.9 (3.4-6.9) SNPs/genome/year • Similar median mutation rates in subgroups (households, travelers) • No hotspots for SNPs within the genome.
Collapse
Affiliation(s)
- Tine Graakjær Larsen
- Department of Clinical Microbiology, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark
- Department of Infectious Disease Epidemiology and Prevention, Statens Serum Institut, Copenhagen, Denmark
| | | | - Peder Worning
- Department of Clinical Microbiology, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark
| | - Henrik Westh
- Department of Clinical Microbiology, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Mette Damkjær Bartels
- Department of Clinical Microbiology, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark.
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark.
| |
Collapse
|
2
|
Geofrey MA, Sauli E, Kanje LE, Beti M, Shayo MJ, Kuchaka D, van Zwetselaar M, Wadugu B, Mmbaga B, Mkumbaye SI, Kumburu H, Sonda T. Genomic characterization of methicillin-resistant Staphylococcus aureus isolated from patients attending regional referral hospitals in Tanzania. BMC Med Genomics 2024; 17:211. [PMID: 39143496 PMCID: PMC11323609 DOI: 10.1186/s12920-024-01979-4] [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: 03/25/2024] [Accepted: 08/01/2024] [Indexed: 08/16/2024] Open
Abstract
BACKGROUND Methicillin-resistant Staphylococcus aureus (MRSA) colonization increases the risk of subsequent infection by MRSA strain complex interlinking between hospital and community-acquired MRSA which increases the chance of drug resistance and severity of the disease. OBJECTIVE Genomic characterization of Staphylococcus aures strains isolated from patients attending regional referral hospitals in Tanzania. METHODOLOGY A laboratory-based cross-sectional study using short read-based sequencing technology, (Nextseq550,Illumina, Inc. San diego, California, USA). The samples used were collected from patients attending selected regional referral hospitals in Tanzania under the SeqAfrica project. Sequences were analyzed using tools available in the center for genomic and epidemiology server, and visualization of the phylogenetic tree was performed in ITOL 6.0. SPSS 28.0 was used for statistical analysis. RESULTS Among 103 sequences of S. aureus, 48.5% (50/103) carry the mecA gene for MRSA. High proportions of MRSA were observed among participants aged between 18 and 34 years (52.4%), in females (54.3%), and among outpatients (60.5%). The majority of observed MRSA carried plasmids rep5a (92.0%), rep16 (90.0%), rep7c (90.0%), rep15 (82.0%), rep19 (80.0%) and rep10 (72.0%). Among all plasmids observed rep5a, rep16, rep20, and repUS70 carried the blaZ gene, rep10 carried the erm(C) gene and rep7a carried the tet(K) gene. MLST and phylogeny analysis reveal high diversity among MRSA. Six different clones were observed circulating at selected regional hospitals and MRSA with ST8 was dominant. CONCLUSION The study reveals a significant presence of MRSA in Staphylococcus aureus strains from Tanzanian regional hospitals, with nearly half carrying the mecA gene. MRSA is notably prevalent among young adults, females, and outpatients, showing high genetic diversity and dominance of ST8. Various plasmids carrying resistance genes indicate a complex resistance profile, highlighting the need for targeted interventions to manage MRSA infections in Tanzania.
Collapse
Affiliation(s)
- Mujungu A Geofrey
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania.
- Kilimanjaro Clinical Research Institute, Kilimanjaro, Tanzania.
- Catholic University of Health and Allied Sciences, Mwanza, Tanzania.
| | - Elingarami Sauli
- Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
| | - Livin E Kanje
- Kilimanjaro Clinical Research Institute, Kilimanjaro, Tanzania
| | - Melkiory Beti
- Kilimanjaro Clinical Research Institute, Kilimanjaro, Tanzania
| | - Mariana J Shayo
- Kilimanjaro Clinical Research Institute, Kilimanjaro, Tanzania
- Department of Biological and Pre-Clinical Studies, Muhimbili University, Dar es salaam, Tanzania
| | - Davis Kuchaka
- Kilimanjaro Clinical Research Institute, Kilimanjaro, Tanzania
| | | | - Boaz Wadugu
- Kilimanjaro Clinical Research Institute, Kilimanjaro, Tanzania
| | - Blandina Mmbaga
- Kilimanjaro Clinical Research Institute, Kilimanjaro, Tanzania
- Department of Microbiology and Immunology, Kilimanjaro Christian Medical University College, Kilimanjaro, Tanzania
- Department of Clinical Laboratory, Kilimanjaro Christian Medical Centre, Kilimanjaro, Tanzania
| | - Sixbert Isdory Mkumbaye
- Kilimanjaro Clinical Research Institute, Kilimanjaro, Tanzania
- Department of Microbiology and Immunology, Kilimanjaro Christian Medical University College, Kilimanjaro, Tanzania
- Department of Clinical Laboratory, Kilimanjaro Christian Medical Centre, Kilimanjaro, Tanzania
| | - Happiness Kumburu
- Kilimanjaro Clinical Research Institute, Kilimanjaro, Tanzania
- Department of Microbiology and Immunology, Kilimanjaro Christian Medical University College, Kilimanjaro, Tanzania
- Department of Clinical Laboratory, Kilimanjaro Christian Medical Centre, Kilimanjaro, Tanzania
| | - Tolbert Sonda
- Kilimanjaro Clinical Research Institute, Kilimanjaro, Tanzania
- Department of Microbiology and Immunology, Kilimanjaro Christian Medical University College, Kilimanjaro, Tanzania
- Department of Clinical Laboratory, Kilimanjaro Christian Medical Centre, Kilimanjaro, Tanzania
| |
Collapse
|
3
|
Kyser AJ, Fotouh B, Mahmoud MY, Frieboes HB. Rising role of 3D-printing in delivery of therapeutics for infectious disease. J Control Release 2024; 366:349-365. [PMID: 38182058 PMCID: PMC10923108 DOI: 10.1016/j.jconrel.2023.12.051] [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: 10/03/2023] [Revised: 12/18/2023] [Accepted: 12/28/2023] [Indexed: 01/07/2024]
Abstract
Modern drug delivery to tackle infectious disease has drawn close to personalizing medicine for specific patient populations. Challenges include antibiotic-resistant infections, healthcare associated infections, and customizing treatments for local patient populations. Recently, 3D-printing has become a facilitator for the development of personalized pharmaceutic drug delivery systems. With a variety of manufacturing techniques, 3D-printing offers advantages in drug delivery development for controlled, fine-tuned release and platforms for different routes of administration. This review summarizes 3D-printing techniques in pharmaceutics and drug delivery focusing on treating infectious diseases, and discusses the influence of 3D-printing design considerations on drug delivery platforms targeting these diseases. Additionally, applications of 3D-printing in infectious diseases are summarized, with the goal to provide insight into how future delivery innovations may benefit from 3D-printing to address the global challenges in infectious disease.
Collapse
Affiliation(s)
- Anthony J Kyser
- Department of Bioengineering, University of Louisville Speed School of Engineering, Louisville, KY 40202, USA.
| | - Bassam Fotouh
- Department of Bioengineering, University of Louisville Speed School of Engineering, Louisville, KY 40202, USA.
| | - Mohamed Y Mahmoud
- Department of Bioengineering, University of Louisville Speed School of Engineering, Louisville, KY 40202, USA; Department of Toxicology and Forensic Medicine, Faculty of Veterinary Medicine, Cairo University, Egypt.
| | - Hermann B Frieboes
- Department of Bioengineering, University of Louisville Speed School of Engineering, Louisville, KY 40202, USA; Center for Predictive Medicine, University of Louisville, Louisville, KY 40202, USA; Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40202, USA; UofL Health - Brown Cancer Center, University of Louisville, KY 40202, USA.
| |
Collapse
|
4
|
Hayles A, Bright R, Nguyen NH, Truong VK, Vongsvivut J, Wood J, Kidd SP, Vasilev K. Staphylococcus aureus surface attachment selectively influences tolerance against charged antibiotics. Acta Biomater 2024; 175:369-381. [PMID: 38141932 DOI: 10.1016/j.actbio.2023.12.029] [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: 07/26/2023] [Revised: 11/21/2023] [Accepted: 12/17/2023] [Indexed: 12/25/2023]
Abstract
The threat of infection during implant placement surgery remains a considerable burden for millions of patients worldwide. To combat this threat, clinicians employ a range of anti-infective strategies and practices. One of the most common interventions is the use of prophylactic antibiotic treatment during implant placement surgery. However, these practices can be detrimental by promoting the resilience of biofilm-forming bacteria and enabling them to persist throughout treatment and re-emerge later, causing a life-threatening infection. Thus, it is of the utmost importance to elucidate the events occurring during the initial stages of bacterial surface attachment and determine whether any biological processes may be targeted to improve surgical outcomes. Using gene expression analysis, we identified a cellular mechanism of S. aureus which modifies its cell surface charge following attachment to a medical grade titanium surface. We determined the upregulation of two systems involved in the d-alanylation of teichoic acids and the lysylation of phosphatidylglycerol. We supported these molecular findings by utilizing synchrotron-sourced attenuated total reflection Fourier-transform infrared microspectroscopy to analyze the biomolecular properties of the S. aureus cell surface following attachment. As a direct consequence, S. aureus quickly becomes substantially more tolerant to the positively charged vancomycin, but not the negatively charged cefazolin. The present study can assist clinicians in rationally selecting the most potent antibiotic in prophylaxis treatments. Furthermore, it highlights a cellular process that could potentially be targeted by novel technologies and strategies to improve the outcome of antibiotic prophylaxis during implant placement surgery. STATEMENT OF SIGNIFICANCE: The antibiotic tolerance of bacteria in biofilm is a well-established phenomenon. However, the physiological adaptations employed by Staphylococcus aureus to increase its antibiotic tolerance during the early stages of surface attachment are poorly understood. Using multiple techniques, including gene expression analysis and synchrotron-sourced Fourier-transform infrared microspectroscopy, we generated insights into the physiological response of S. aureus following attachment to a medical grade titanium surface. We showed that this phenotypic transition enables S. aureus to better tolerate the positively charged vancomycin, but not the negatively charged cefazolin. These findings shed light on the antibiotic tolerance mechanisms employed by S. aureus to survive prophylactically administered antibiotics and can help clinicians to protect patients from infections.
Collapse
Affiliation(s)
- Andrew Hayles
- College of Medicine and Public Health, Flinders University, Bedford Park, South Australia, 5042 Australia.
| | - Richard Bright
- College of Medicine and Public Health, Flinders University, Bedford Park, South Australia, 5042 Australia
| | - Ngoc Huu Nguyen
- School of Biomedical Engineering, Faculty of Engineering, University of Sydney, Sydney, Australia
| | - Vi Khanh Truong
- College of Medicine and Public Health, Flinders University, Bedford Park, South Australia, 5042 Australia
| | - Jitraporn Vongsvivut
- Infrared Microspectroscopy (IRM) Beamline, ANSTO ‒ Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Jonathan Wood
- Academic Unit of STEM, University of South Australia, Adelaide 5095, South Australia, Australia
| | - Stephen P Kidd
- Department of Molecular and Biomedical Sciences, School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia; Australian Centre for Antimicrobial Resistance Ecology, The University of Adelaide, Adelaide, SA 5005, Australia
| | - Krasimir Vasilev
- College of Medicine and Public Health, Flinders University, Bedford Park, South Australia, 5042 Australia.
| |
Collapse
|
5
|
Pashizeh F, Mansouri A, Bazzazan S, Abdihaji M, Khaleghian M, Bazzazan S, Rezei N, Eskandari A, Mashayekhi F, Heydari M, Tavakkoli Yaraki M. Bioresponsive gingerol-loaded alginate-coated niosomal nanoparticles for targeting intracellular bacteria and cancer cells. Int J Biol Macromol 2024; 258:128957. [PMID: 38154726 DOI: 10.1016/j.ijbiomac.2023.128957] [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: 09/15/2023] [Revised: 12/14/2023] [Accepted: 12/19/2023] [Indexed: 12/30/2023]
Abstract
Targeting and treating intracellular pathogen infections has been long-standing challenge, particularly in light of the escalating prevalence of antimicrobial resistance. Herein, an optimum formulation of alginate (AL)-coated niosome-based carriers for delivery of herbal extract Gingerol (Gin) was developed to treat intracellular pathogen infections and cancer cells. We used Gin-Nio@AL as a model drug to assess its efficacy against Gram-negative/positive bacteria and breast cancer cell lines. Our investigation affirmed its heightened antibacterial and anticancer properties. The antibacterial activity of Gin-Nio@AL against intracellular Staphylococcus aureus (S. aureus) and pseudomonas aeruginosa (P. aeruginosa) was also tested. In the current study, the niosome nanoparticles containing herbal extract Gingerol were optimized regarding lipid content and Surfactant per Cholesterol molar ratio. The developed formulation provided potential advantages, such as smooth globular surface morphology, small diameter (240.68 nm), pH-sensitive sustained release, and high entrapment efficiency (94.85 %). The release rate of Gin from AL-coated niosomes (Gin-Nio@AL) in physiological and acidic pH is lower than uncoated nanoparticles (Gin-Nio). Besides, the release rate of Gin from niosomal formulations increased in acidic pH. The Gin-Nio@AL demonstrated good antimicrobial activity against S. aureus and P. aeruginosa, and compared to Gin-Nio, the MIC values decreased to 7.82 ± 0.00 and 1.95 ± 0.00 μg/mL, respectively. In addition, the time-kill assay results showed that the developed formulation significantly reduced the number of bacteria in both strains compared to other tested groups. The microtiter data and scanning electron microscope micrography showed that Gin-Nio@AL has a more significant inhibitory effect on biofilm formation than Gin-Nio and Gin. The cell cytotoxicity evaluation showed that Gin-Nio@AL reduced the survival rate of MDA-MB-231 cancer cells to 52.4 % and 45.2 % after 48 h and 72 h, respectively. The elimination of intracellular pathogens was investigated through a breast cancer cell infection in an in vitro model. Gin-Nio@AL exhibited an enhanced and sustained intracellular antibacterial activity against pathogens-infected breast cancer cells compared to other tested formulations. Overall, Gin-Nio@AL enables the triggered release and targeting of intra-extra cellular bacteria and cancer cells and provides a novel and promising candidate for treating intracellular pathogen infections and cancer cells.
Collapse
Affiliation(s)
- Fatemeh Pashizeh
- Department of Immunology, School of Medicine, Shahid Sadoughi University of Medical Science Yazd, Iran
| | - Afsoun Mansouri
- School of Pharmacy and Pharmaceutical Sciences, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
| | - Saina Bazzazan
- Department of Community Medicine, Mashhad Branch, Islamic Azad University, Mashhad, Iran
| | - Mohammadreza Abdihaji
- Department of Biology, The Center for Genomics and Bioinformatics, Indiana University, Bloomington, IN, USA
| | | | - Saba Bazzazan
- Department of Community Medicine, Mashhad Branch, Islamic Azad University, Mashhad, Iran
| | - Niloufar Rezei
- School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran
| | - Alireza Eskandari
- CTERC, NRITLD, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Farzaneh Mashayekhi
- Rasoul Akram Hospital, Iran University of Medical Sciences (IUMS), Tehran, Iran
| | - Maryam Heydari
- Department of Cell and Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
| | - Mohammad Tavakkoli Yaraki
- School of Natural Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, NSW 2109, Australia.
| |
Collapse
|
6
|
Kamala K, Sivaperumal P. Prevalence of enterotoxin genes of Staphylococcus sp. isolated from marine fish to reveal seafood contamination. MARINE POLLUTION BULLETIN 2023; 195:115464. [PMID: 37666137 DOI: 10.1016/j.marpolbul.2023.115464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/22/2023] [Accepted: 08/26/2023] [Indexed: 09/06/2023]
Abstract
Seafood is a valuable nutritional source, but it is highly susceptible to bacterial contamination, posing a severe health risk to humans. Enterotoxin-producing genes carrying Staphylococcus sp. are a significant concern in marine fish. This study aimed to investigate the prevalence of enterotoxin genes in Staphylococcus sp. isolated from 17 common fish species and emphasise the need for improving seafood quality and hygiene. The potential risks of contamination by enterotoxin-producing Staphylococcus sp. were assessed. The results indicated the risk associated with the consumption of contaminated seafood, especially from marketed and frozen samples. Gene expression analysis on a heat map revealed that samples stored in markets are heavily loaded with Staphylococcus enterotoxin genes due to the unhygienic water that was used from the local markets for fish processing. To enhance seafood quality, effective measures on handling and storage should be regularly monitored, and they must be implemented throughout the local seafood markets.
Collapse
Affiliation(s)
- Kannan Kamala
- Centre for Marine Actinobacterial Research (CMAR), Department of Physiology, Saveetha Dental College and Hospitals, Saveetha Institute of Medical & Technical Sciences, Saveetha University, Chennai 600077, Tamil Nadu, India
| | - Pitchiah Sivaperumal
- Marine Biomedical Research Lab & Environmental Toxicology Unit, Centre for Marine Research and Conservation, Saveetha Dental College and Hospitals, Saveetha Institute of Medical & Technical Sciences, Saveetha University, Chennai 600077, Tamil Nadu, India.
| |
Collapse
|
7
|
Anderson EE, Dyzenhaus S, Ilmain JK, Sullivan MJ, van Bakel H, Torres VJ. SarS Is a Repressor of Staphylococcus aureus Bicomponent Pore-Forming Leukocidins. Infect Immun 2023; 91:e0053222. [PMID: 36939325 PMCID: PMC10112191 DOI: 10.1128/iai.00532-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 02/20/2023] [Indexed: 03/21/2023] Open
Abstract
Staphylococcus aureus is a successful pathogen that produces a wide range of virulence factors that it uses to subvert and suppress the immune system. These include the bicomponent pore-forming leukocidins. How the expression of these toxins is regulated is not completely understood. Here, we describe a screen to identify transcription factors involved in the regulation of leukocidins. The most prominent discovery from this screen is that SarS, a known transcription factor which had previously been described as a repressor of alpha-toxin expression, was found to be a potent repressor of leukocidins LukED and LukSF-PV. We found that inactivating sarS resulted in increased virulence both in an ex vivo model using primary human neutrophils and in an in vivo infection model in mice. Further experimentation revealed that SarS represses leukocidins by serving as an activator of Rot, a critical repressor of toxins, as well as by directly binding and repressing the leukocidin promoters. By studying contemporary clinical isolates, we identified naturally occurring mutations in the sarS promoter that resulted in overexpression of sarS and increased repression of leukocidins in USA300 bloodstream clinical isolates. Overall, these data establish SarS as an important repressor of leukocidins and expand our understanding of how these virulence factors are being regulated in vitro and in vivo by S. aureus.
Collapse
Affiliation(s)
- Exene E. Anderson
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Sophie Dyzenhaus
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Juliana K. Ilmain
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| | - Mitchell J. Sullivan
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Harm van Bakel
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Icahn Genomics Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Victor J. Torres
- Department of Microbiology, New York University Grossman School of Medicine, New York, New York, USA
| |
Collapse
|
8
|
Kowalewicz C, Timmermans M, Fretin D, Wattiau P, Boland C. An in-house 45-plex array for the detection of antimicrobial resistance genes in Gram-positive bacteria. Microbiologyopen 2023; 12:e1341. [PMID: 36825880 PMCID: PMC9791161 DOI: 10.1002/mbo3.1341] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 12/02/2022] [Indexed: 12/27/2022] Open
Abstract
Identifying antimicrobial resistance (AMR) genes and determining their occurrence in Gram-positive bacteria provide useful data to understand how resistance can be acquired and maintained in these bacteria. We describe an in-house bead array targeting AMR genes of Gram-positive bacteria and allowing their rapid detection all at once at a reduced cost. A total of 41 AMR probes were designed to target genes frequently associated with resistance to tetracycline, macrolides, lincosamides, streptogramins, pleuromutilins, phenicols, glycopeptides, aminoglycosides, diaminopyrimidines, oxazolidinones and particularly shared among Enterococcus and Staphylococcus spp. A collection of 124 enterococci and 62 staphylococci isolated from healthy livestock animals through the official Belgian AMR monitoring (2018-2020) was studied with this array from which a subsample was further investigated by whole-genome sequencing. The array detected AMR genes associated with phenotypic resistance for 93.0% and 89.2% of the individual resistant phenotypes in enterococci and staphylococci, respectively. Although linezolid is not used in veterinary medicine, linezolid-resistant isolates were detected. These were characterized by the presence of optrA and poxtA, providing cross-resistance to other antibiotics. Rarer, vancomycin resistance was conferred by the vanA or by the vanL cluster. Numerous resistance genes circulating among Enterococcus and Staphylococcus spp. were detected by this array allowing rapid screening of a large strain collection at an affordable cost. Our data stress the importance of interpreting AMR with caution and the complementarity of both phenotyping and genotyping methods. This array is now available to assess other One-Health AMR reservoirs.
Collapse
Affiliation(s)
| | | | - David Fretin
- Veterinary Bacteriology, SciensanoIxellesBelgium
| | | | | |
Collapse
|
9
|
Antibiotics Limit Adaptation of Drug-Resistant Staphylococcus aureus to Hypoxia. Antimicrob Agents Chemother 2022; 66:e0092622. [PMID: 36409116 PMCID: PMC9765076 DOI: 10.1128/aac.00926-22] [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: 11/23/2022] Open
Abstract
Bacterial pathogens are confronted with a range of challenges at the site of infection, including exposure to antibiotic treatment and harsh physiological conditions, that can alter the fitness benefits and costs of acquiring antibiotic resistance. Here, we develop an experimental system to recapitulate resistance gene acquisition by Staphylococcus aureus and test how the subsequent evolution of the resistant bacterium is modulated by antibiotic treatment and oxygen levels, both of which are known to vary extensively at sites of infection. We show that acquiring tetracycline resistance was costly, reducing competitive growth against the isogenic strain without the resistance gene in the absence of the antibiotic, for S. aureus under hypoxic but not normoxic conditions. Treatment with tetracycline or doxycycline drove the emergence of enhanced resistance through mutations in an RluD-like protein-encoding gene and duplications of tetL, encoding the acquired tetracycline-specific efflux pump. In contrast, evolutionary adaptation by S. aureus to hypoxic conditions, which evolved in the absence of antibiotics through mutations affecting gyrB, was impeded by antibiotic treatment. Together, these data suggest that the horizontal acquisition of a new resistance mechanism is merely a starting point for the emergence of high-level resistance under antibiotic selection but that antibiotic treatment constrains pathogen adaptation to other important environmental selective forces such as hypoxia, which in turn could limit the survival of these highly resistant but poorly adapted genotypes after antibiotic treatment is ended.
Collapse
|
10
|
Islam S, Callender AC, Ho QN, Wakeman CA. Iron restriction induces the small-colony variant phenotype in Staphylococcus aureus. Front Microbiol 2022; 13:978859. [PMID: 36569073 PMCID: PMC9772265 DOI: 10.3389/fmicb.2022.978859] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 11/21/2022] [Indexed: 12/13/2022] Open
Abstract
Pathogens such as Staphylococcus aureus must overcome host-induced selective pressures, including limited iron availability. To cope with the harsh conditions of the host environment, S. aureus can adapt its physiology in multiple ways. One of these adaptations is the fermenting small-colony variant (SCV) phenotype, which is known to be inherently tolerant to certain classes of antibiotics and heme toxicity. We hypothesized that SCVs might also behave uniquely in response to iron starvation since one of the major cellular uses of iron is the respiration machinery. In this study, a respiring strain of S. aureus and fermenting SCV strains were treated with different concentrations of the iron chelator, 2,2' dipyridyl (DIP). Our data demonstrate that a major impact of iron starvation in S. aureus is the repression of respiration and the induction of the SCV phenotype. We demonstrate that the SCV phenotype transiently induced by iron starvation mimics the aminoglycoside recalcitrance exhibited by genetic SCVs. Furthermore, prolonged growth in iron starvation promotes increased emergence of stable aminoglycoside-resistant SCVs relative to the naturally occurring subpopulation of SCVs within an S. aureus community. These findings may have relevance to physiological and evolutionary processes occurring within bacterial populations infecting iron-limited host environments.
Collapse
Affiliation(s)
| | | | | | - Catherine A. Wakeman
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, United States
| |
Collapse
|
11
|
Adegoke A, Kumar D, Budachetri K, Karim S. Hematophagy and tick-borne Rickettsial pathogen shape the microbial community structure and predicted functions within the tick vector, Amblyomma maculatum. Front Cell Infect Microbiol 2022; 12:1037387. [PMID: 36478675 PMCID: PMC9719966 DOI: 10.3389/fcimb.2022.1037387] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 11/03/2022] [Indexed: 11/22/2022] Open
Abstract
Background Ticks are the primary vectors of emerging and resurging pathogens of public health significance worldwide. Analyzing tick bacterial composition, diversity, and functionality across developmental stages and tissues is crucial for designing new strategies to control ticks and prevent tick-borne diseases. Materials and methods Here, we explored the microbial communities across the developmental timeline and in different tissues of the Gulf-Coast ticks (Amblyomma maculatum). Using a high-throughput sequencing approach, the influence of blood meal and Rickettsia parkeri, a spotted fever group rickettsiae infection in driving changes in microbiome composition, diversity, and functionality was determined. Results This study shows that the core microbiome of Am. maculatum comprises ten core bacterial genera. The genus Rickettsia, Francisella, and Candidatus_Midichloria are the key players, with positive interactions within each developmental stage and adult tick organ tested. Blood meal and Rickettsia parkeri led to an increase in the bacterial abundance in the tissues. According to functional analysis, the increase in bacterial numbers is positively correlated to highly abundant energy metabolism orthologs with blood meal. Correlation analysis identified an increase in OTUs identified as Candidatus Midichloria and a subsequent decrease in Francisella OTUs in Rickettsia parkeri infected tick stages and tissues. Results demonstrate the abundance of Rickettsia and Francisella predominate in the core microbiome of Am. maculatum, whereas Candidatus_Midichloria and Cutibacterium prevalence increase with R. parkeri-infection. Network analysis and functional annotation suggest that R. parkeri interacts positively with Candidatus_Midichloria and negatively with Francisella. Conclusion We conclude that tick-transmitted pathogens, such as R. parkeri establishes infection by interacting with the core microbiome of the tick vector.
Collapse
Affiliation(s)
- Abdulsalam Adegoke
- School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MS, United States
| | - Deepak Kumar
- School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MS, United States
| | - Khemraj Budachetri
- School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MS, United States
- Department of Veterinary Biosciences, The Ohio State University, Columbus, OH, United States
| | - Shahid Karim
- School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MS, United States
- Center for Molecular and Cellular Biosciences, University of Southern Mississippi, Hattiesburg, MS, United States
| |
Collapse
|
12
|
Perry WJ, Grunenwald CM, Van de Plas R, Witten JC, Martin DR, Apte SS, Cassat JE, Pettersson GB, Caprioli RM, Skaar EP, Spraggins JM. Visualizing Staphylococcus aureus pathogenic membrane modification within the host infection environment by multimodal imaging mass spectrometry. Cell Chem Biol 2022; 29:1209-1217.e4. [PMID: 35654040 PMCID: PMC9308753 DOI: 10.1016/j.chembiol.2022.05.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/10/2021] [Accepted: 05/11/2022] [Indexed: 11/30/2022]
Abstract
Bacterial pathogens have evolved virulence factors to colonize, replicate, and disseminate within the vertebrate host. Although there is an expanding body of literature describing how bacterial pathogens regulate their virulence repertoire in response to environmental signals, it is challenging to directly visualize virulence response within the host tissue microenvironment. Multimodal imaging approaches enable visualization of host-pathogen molecular interactions. Here we demonstrate multimodal integration of high spatial resolution imaging mass spectrometry and microscopy to visualize Staphylococcus aureus envelope modifications within infected murine and human tissues. Data-driven image fusion of fluorescent bacterial reporters and matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance imaging mass spectrometry uncovered S. aureus lysyl-phosphatidylglycerol lipids, localizing to select bacterial communities within infected tissue. Absence of lysyl-phosphatidylglycerols is associated with decreased pathogenicity during vertebrate colonization as these lipids provide protection against the innate immune system. The presence of distinct staphylococcal lysyl-phosphatidylglycerol distributions within murine and human infections suggests a heterogeneous, spatially oriented microbial response to host defenses.
Collapse
Affiliation(s)
- William J Perry
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37232, USA; Department of Chemistry, Vanderbilt University, Nashville, TN 37212, USA; Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University, Nashville, TN 37232, USA
| | - Caroline M Grunenwald
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University, Nashville, TN 37232, USA; Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37212, USA
| | - Raf Van de Plas
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37232, USA; Delft Center for Systems and Control, Delft University of Technology - TU Delft, Delft, the Netherlands; Department of Biochemistry, Vanderbilt University, Nashville, TN 37212, USA
| | - James C Witten
- Department of Thoracic and Cardiovascular Surgery, Cleveland Clinic Heart and Vascular Institute, Cleveland, OH 44195, USA
| | - Daniel R Martin
- Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Suneel S Apte
- Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - James E Cassat
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University, Nashville, TN 37232, USA; Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37212, USA; Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Biomedical Engineering, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Gösta B Pettersson
- Department of Thoracic and Cardiovascular Surgery, Cleveland Clinic Heart and Vascular Institute, Cleveland, OH 44195, USA
| | - Richard M Caprioli
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37232, USA; Department of Chemistry, Vanderbilt University, Nashville, TN 37212, USA; Department of Biochemistry, Vanderbilt University, Nashville, TN 37212, USA; Department of Pharmacology, Vanderbilt University, Nashville, TN 37212, USA; Department of Medicine, Vanderbilt University, Nashville, TN 37212, USA
| | - Eric P Skaar
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University, Nashville, TN 37232, USA; Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37212, USA.
| | - Jeffrey M Spraggins
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37232, USA; Department of Chemistry, Vanderbilt University, Nashville, TN 37212, USA; Department of Biochemistry, Vanderbilt University, Nashville, TN 37212, USA; Department of Cell & Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA.
| |
Collapse
|
13
|
Menard G, Silard C, Suriray M, Rouillon A, Augagneur Y. Thirty Years of sRNA-Mediated Regulation in Staphylococcus aureus: From Initial Discoveries to In Vivo Biological Implications. Int J Mol Sci 2022; 23:ijms23137346. [PMID: 35806357 PMCID: PMC9266662 DOI: 10.3390/ijms23137346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/20/2022] [Accepted: 06/28/2022] [Indexed: 01/27/2023] Open
Abstract
Staphylococcus aureus is a widespread livestock and human pathogen that colonizes diverse microenvironments within its host. Its adaptation to the environmental conditions encountered within humans relies on coordinated gene expression. This requires a sophisticated regulatory network, among which regulatory RNAs (usually called sRNAs) have emerged as key players over the last 30 years. In S. aureus, sRNAs regulate target genes at the post-transcriptional level through base–pair interactions. The functional characterization of a subset revealed that they participate in all biological processes, including virulence, metabolic adaptation, and antibiotic resistance. In this review, we report 30 years of S. aureus sRNA studies, from their discovery to the in-depth characterizations of some of them. We also discuss their actual in vivo contribution, which is still lagging behind, and their place within the complex regulatory network. These shall be key aspects to consider in order to clearly uncover their in vivo biological functions.
Collapse
Affiliation(s)
- Guillaume Menard
- CHU Rennes, INSERM, BRM (Bacterial Regulatory RNAs and Medicine), SB2H (Service de Bactériologie Hygiène-Hospitalière), University Rennes, UMR_S 1230, F-35000 Rennes, France; (G.M.); (M.S.)
| | - Chloé Silard
- INSERM, BRM (Bacterial Regulatory RNAs and Medicine), University Rennes, UMR_S 1230, F-35000 Rennes, France; (C.S.); (A.R.)
| | - Marie Suriray
- CHU Rennes, INSERM, BRM (Bacterial Regulatory RNAs and Medicine), SB2H (Service de Bactériologie Hygiène-Hospitalière), University Rennes, UMR_S 1230, F-35000 Rennes, France; (G.M.); (M.S.)
| | - Astrid Rouillon
- INSERM, BRM (Bacterial Regulatory RNAs and Medicine), University Rennes, UMR_S 1230, F-35000 Rennes, France; (C.S.); (A.R.)
| | - Yoann Augagneur
- INSERM, BRM (Bacterial Regulatory RNAs and Medicine), University Rennes, UMR_S 1230, F-35000 Rennes, France; (C.S.); (A.R.)
- Correspondence: ; Tel.: +33-223234631
| |
Collapse
|
14
|
Ménard G, Rouillon A, Cattoir V, Donnio PY. Galleria mellonella as a Suitable Model of Bacterial Infection: Past, Present and Future. Front Cell Infect Microbiol 2022; 11:782733. [PMID: 35004350 PMCID: PMC8727906 DOI: 10.3389/fcimb.2021.782733] [Citation(s) in RCA: 59] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 12/01/2021] [Indexed: 12/16/2022] Open
Abstract
The increasing interest for Galleria mellonella larvae as an infection model is evidenced by the number of papers reporting its use, which increases exponentially since the early 2010s. This popularity was initially linked to limitation of conventional animal models due to financial, technical and ethical aspects. In comparison, alternative models (e.g. models using Caenorhabditis elegans, Drosophila melanogaster or G. mellonella) were cheap, simple to use and not limited by ethical regulation. Since then, similar results have been established with G. mellonella model comparatively to vertebrates, and it is more and more often used as a robust model per se, not only as an alternative to the murine model. This review attempts to summarize the current knowledge supporting the development of this model, both on immunological and microbiological aspects. For that, we focus on investigation of virulence and new therapies for the most important pathogenic bacteria. We also discuss points out directions for standardization, as well as recent advances and new perspectives for monitoring host-pathogen interactions.
Collapse
Affiliation(s)
- Guillaume Ménard
- Univ Rennes, CHU Rennes, INSERM, Bacterial Regulatory RNAs and Medicine (BRM), service de Bactériologie Hygiène-Hospitalière (SB2H), UMR_S 1230, Rennes, France
| | - Astrid Rouillon
- Univ Rennes, INSERM, Bacterial Regulatory RNAs and Medicine (BRM), UMR_S 1230, Rennes, France
| | - Vincent Cattoir
- Univ Rennes, CHU Rennes, INSERM, Bacterial Regulatory RNAs and Medicine (BRM), service de Bactériologie Hygiène-Hospitalière (SB2H), UMR_S 1230, Rennes, France
| | - Pierre-Yves Donnio
- Univ Rennes, CHU Rennes, INSERM, Bacterial Regulatory RNAs and Medicine (BRM), service de Bactériologie Hygiène-Hospitalière (SB2H), UMR_S 1230, Rennes, France
| |
Collapse
|
15
|
Heme-Dependent Siderophore Utilization Promotes Iron-Restricted Growth of the Staphylococcus aureus hemB Small-Colony Variant. J Bacteriol 2021; 203:e0045821. [PMID: 34606375 DOI: 10.1128/jb.00458-21] [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] [Indexed: 01/01/2023] Open
Abstract
Respiration-deficient Staphylococcus aureus small-colony variants (SCVs) frequently cause persistent infections, which necessitates they acquire iron, yet how SCVs obtain iron remains unknown. To address this, we created a stable hemB mutant from S. aureus USA300 strain LAC. The hemB SCV utilized exogenously supplied hemin but was attenuated for growth under conditions of iron starvation. Transcriptome sequencing (RNA-seq) showed that both wild-type (WT) S. aureus and the hemB mutant sense and respond to iron starvation; however, growth assays show that the hemB mutant is defective for siderophore-mediated iron acquisition. Indeed, the hemB SCV demonstrated limited utilization of endogenous staphyloferrin B or exogenously provided staphyloferrin A, deferoxamine mesylate (Desferal), and epinephrine. Direct measurement of intracellular ATP in hemB and WT S. aureus revealed that both strains can generate comparable levels of ATP during exponential growth, suggesting defects in ATP production cannot account for the inability to efficiently utilize siderophores. Defective siderophore utilization by hemB bacteria was also evident in vivo, as administration of Desferal failed to promote hemB bacterial growth in every organ analyzed except for the kidneys. In support of the hypothesis that S. aureus accesses heme in kidney abscesses, in vitro analyses revealed that increased hemin availability enables hemB bacteria to utilize siderophores for growth when iron availability is restricted. Taken together, our data support the conclusion that hemin is used not only as an iron source itself but also as a nutrient that promotes utilization of siderophore-iron complexes. IMPORTANCE S. aureus small-colony variants (SCVs) are associated with chronic recurrent infection and worsened clinical outcome. SCVs persist within the host despite administration of antibiotics. This study yields insight into how S. aureus SCVs acquire iron, which during infection of a host is a difficult-to-acquire metal nutrient. Under hemin-limited conditions, hemB S. aureus is impaired for siderophore-dependent growth, and in agreement, murine infection indicates that hemin-deficient SCVs meet their nutritional requirement for iron through utilization of hemin. Importantly, we demonstrate that hemB SCVs rely upon hemin as a nutrient to promote siderophore utilization. Therefore, perturbation of heme biosynthesis and/or utilization represents a viable to strategy to mitigate the ability of SCV bacteria to acquire siderophore-bound iron during infection.
Collapse
|
16
|
He R, Ding C, Luo Y, Guo G, Tang J, Shen H, Wang Q, Zhang X. Congener-Induced Sulfur-Related Metabolism Interference Therapy Promoted by Photothermal Sensitization for Combating Bacteria. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2104410. [PMID: 34486185 DOI: 10.1002/adma.202104410] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 08/09/2021] [Indexed: 06/13/2023]
Abstract
Metabolic homeostasis is vital for individual cells to keep alive. Stronger metabolic homeostasis allows bacteria to survive in vivo and do persistent harm to hosts, which is especially typical in implant-associated infection (IAI) with biofilm intervention. Herein, based on the competitive role of selenium (Se) and sulfur (S) in bacteria metabolism as congeners, a congener-induced sulfur-related metabolism interference therapy (SMIT) eradicating IAI is proposed by specific destruction of bacteria metabolic homeostasis. The original nanodrug manganese diselenide (MnSe2 ) is devised to generate permeable H2 Se in bacteria, triggered by the acidic microenvironment. H2 Se, the congener substitution of H2 S, as a bacteria-specific intermediate metabolite, can embed itself into the H2 S-utilization pathway and further alternatively disrupt the downstream sulfur-related metabolism state inside bacteria. A proteomic study indicates ribosome-related proteins are heavily downregulated and the basic metabolic pathways are mainly disordered after SMIT, revealing the destruction of bacteria metabolic homeostasis. The efficiency of SMIT is significantly promoted with the mild temperature sensitization provided by the photothermal treatment (PTT) of MnSe2 nanoparticles, verified by the proteomic study and the anti-IAI effect in vitro and in vivo. With the intelligent nanodrug, a PTT-promoted SMIT strategy against IAI is provided and a new insight into the interference design toward metabolic homeostasis with biochemical similarity is demonstrated.
Collapse
Affiliation(s)
- Renke He
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, 200233, P. R. China
| | - Cheng Ding
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, 200233, P. R. China
| | - Yao Luo
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, 200233, P. R. China
| | - Geyong Guo
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, 200233, P. R. China
| | - Jin Tang
- Department of Clinical Laboratory, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, 200233, P. R. China
| | - Hao Shen
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, 200233, P. R. China
| | - Qiaojie Wang
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, 200233, P. R. China
| | - Xianlong Zhang
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, 200233, P. R. China
| |
Collapse
|
17
|
Woroszyło M, Ciecholewska-Juśko D, Junka A, Wardach M, Chodaczek G, Dudek B, Fijałkowski K. The Effect of Rotating Magnetic Field on Susceptibility Profile of Methicillin-Resistant Staphylococcus aureus Strains Exposed to Activity of Different Groups of Antibiotics. Int J Mol Sci 2021; 22:ijms222111551. [PMID: 34768983 PMCID: PMC8583794 DOI: 10.3390/ijms222111551] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/19/2021] [Accepted: 10/21/2021] [Indexed: 12/05/2022] Open
Abstract
Methicillin-resistant strains of Staphylococcus aureus (MRSA) have become a global issue for healthcare systems due to their resistance to most β-lactam antibiotics, frequently accompanied by resistance to other classes of antibiotics. In this work, we analyzed the impact of combined use of rotating magnetic field (RMF) with various classes of antibiotics (β-lactams, glycopeptides, macrolides, lincosamides, aminoglycosides, tetracyclines, and fluoroquinolones) against nine S. aureus strains (eight methicillin-resistant and one methicillin-sensitive). The results indicated that the application of RMF combined with antibiotics interfering with cell walls (particularly with the β-lactam antibiotics) translate into favorable changes in staphylococcal growth inhibition zones or in minimal inhibitory concentration values compared to the control settings, which were unexposed to RMF. As an example, the MIC value of cefoxitin was reduced in all MRSA strains by up to 42 times. Apart from the β-lactams, the reduced MIC values were also found for erythromycin, clindamycin, and tetracycline (three strains), ciprofloxacin (one strain), gentamicin (six strains), and teicoplanin (seven strains). The results obtained with the use of in vitro biofilm model confirm that the disturbances caused by RMF in the bacterial cell walls increase the effectiveness of the antibiotics towards MRSA. Because the clinical demand for new therapeutic options effective against MRSA is undisputable, the outcomes and conclusions drawn from the present study may be considered an important road into the application of magnetic fields to fight infections caused by methicillin-resistant staphylococci.
Collapse
Affiliation(s)
- Marta Woroszyło
- Department of Microbiology and Biotechnology, Faculty of Biotechnology and Animal Husbandry, West Pomeranian University of Technology in Szczecin, Piastów 45, 70-311 Szczecin, Poland; (M.W.); (D.C.-J.)
| | - Daria Ciecholewska-Juśko
- Department of Microbiology and Biotechnology, Faculty of Biotechnology and Animal Husbandry, West Pomeranian University of Technology in Szczecin, Piastów 45, 70-311 Szczecin, Poland; (M.W.); (D.C.-J.)
| | - Adam Junka
- Department of Pharmaceutical Microbiology and Parasitology, Faculty of Pharmacy, Medical University of Wroclaw, Borowska 211a, 50-534 Wrocław, Poland
- Laboratory of Microbiology, Łukasiewicz Research Network—PORT Polish Center for Technology Development, 54-066 Wrocław, Poland
- Correspondence: (A.J.); (K.F.); Tel.: +48-88-922-9341 (A.J.); +48-91-449-6714 (K.F.)
| | - Marcin Wardach
- Faculty of Electrical Engineering, West Pomeranian University of Technology in Szczecin, Sikorskiego 37, 70-313 Szczecin, Poland;
| | - Grzegorz Chodaczek
- Laboratory of Confocal Microscopy, Łukasiewicz Research Network—PORT Polish Center for Technology Development, Stabłowicka 147, 54-066 Wrocław, Poland;
| | - Bartłomiej Dudek
- Department of Microbiology, Institute of Genetics and Microbiology, University of Wrocław, Stanisława Przybyszewskiego 63, 51-148 Wrocław, Poland;
| | - Karol Fijałkowski
- Department of Microbiology and Biotechnology, Faculty of Biotechnology and Animal Husbandry, West Pomeranian University of Technology in Szczecin, Piastów 45, 70-311 Szczecin, Poland; (M.W.); (D.C.-J.)
- Correspondence: (A.J.); (K.F.); Tel.: +48-88-922-9341 (A.J.); +48-91-449-6714 (K.F.)
| |
Collapse
|
18
|
McLeod JR, Harvey PA, Detweiler CS. An Oral Fluorouracil Prodrug, Capecitabine, Mitigates a Gram-Positive Systemic Infection in Mice. Microbiol Spectr 2021; 9:e0027521. [PMID: 34190602 PMCID: PMC8419118 DOI: 10.1128/spectrum.00275-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 05/21/2021] [Indexed: 01/11/2023] Open
Abstract
New classes of antibiotics are needed to fight bacterial infections, and repurposing existing drugs as antibiotics may enable rapid deployment of new treatments. Screens for antibacterials have been traditionally performed in standard laboratory media, but bacterial pathogens experience very different environmental conditions during infection, including nutrient limitation. To introduce the next generation of researchers to modern drug discovery methods, we developed a course-based undergraduate research experience (CURE) in which undergraduate students screened a library of FDA-approved drugs for their ability, in a nutrient-poor medium, to prevent the growth of the human Gram-negative bacterial pathogen Salmonella enterica serovar Typhimurium. The nine drugs identified all disrupt DNA metabolism in bacteria and eukaryotes. One of the hit compounds, capecitabine, is a well-tolerated oncology drug that is administered orally, a preferred treatment route. We demonstrated that capecitabine is more effective at inhibiting S. Typhimurium growth in nutrient-limited than in standard rich microbiological broth, an explanation for why the antibiotic activity of this compound has not been previously recognized. Capecitabine is enzymatically converted to the active pyrimidine analogue, fluorouracil (5-FU), and Gram-positive bacteria, including Staphylococcus aureus, are significantly more sensitive to 5-FU than Gram-negative bacteria. We therefore tested capecitabine for efficacy in a murine model of S. aureus peritonitis. Oral capecitabine administration reduced the colonization of tissues and increased animal survival in a dose-responsive manner. Since capecitabine is inexpensive, orally available, and relatively safe, it may have utility for treatment of intractable Gram-positive bacterial infections. IMPORTANCE As bacterial infections become increasingly insensitive to antibiotics, whether established, off-patent drugs could treat infections becomes an important question. At the same time, basic research has revealed that during infection, mammals starve pathogens for nutrients and, in response, bacteria dramatically alter their biology. Therefore, it may be fruitful to search for drugs that could be repurposed as antibiotics using bacteria grown with limited nutrients. This approach, executed with undergraduate student researchers, identified nine drugs known to interfere with the production and/or function of DNA. We further explored one of these drugs, capecitabine, a well-tolerated human oncology drug. Oral administration of capecitabine reduced infection with the human pathogen Staphylococcus aureus and increased survival in mice. These data suggest that capecitabine has potential as a therapy for patients with otherwise untreatable bacterial infections.
Collapse
Affiliation(s)
- Jack R. McLeod
- Department of Molecular Cellular and Developmental Biology, University of Colorado, Boulder, Colorado, USA
| | - Pamela A. Harvey
- Department of Molecular Cellular and Developmental Biology, University of Colorado, Boulder, Colorado, USA
| | - Corrella S. Detweiler
- Department of Molecular Cellular and Developmental Biology, University of Colorado, Boulder, Colorado, USA
| |
Collapse
|
19
|
Knott S, Curry D, Zhao N, Metgud P, Dastgheyb SS, Purtill C, Harwood M, Chen AF, Schaer TP, Otto M, Hickok NJ. Staphylococcus aureus Floating Biofilm Formation and Phenotype in Synovial Fluid Depends on Albumin, Fibrinogen, and Hyaluronic Acid. Front Microbiol 2021; 12:655873. [PMID: 33995317 PMCID: PMC8117011 DOI: 10.3389/fmicb.2021.655873] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 03/19/2021] [Indexed: 11/13/2022] Open
Abstract
Biofilms are typically studied in bacterial media that allow the study of important properties such as bacterial growth. However, the results obtained in such media cannot take into account the bacterial localization/clustering caused by bacteria-protein interactions in vivo and the accompanying alterations in phenotype, virulence factor production, and ultimately antibiotic tolerance. We and others have reported that methicillin-resistant or methicillin-susceptible Staphylococcus aureus (MRSA or MSSA, respectively) and other pathogens assemble a proteinaceous matrix in synovial fluid. This proteinaceous bacterial aggregate is coated by a polysaccharide matrix as is characteristic of biofilms. In this study, we identify proteins important for this aggregation and determine the concentration ranges of these proteins that can reproduce bacterial aggregation. We then test this protein combination for its ability to cause marked aggregation, antibacterial tolerance, preservation of morphology, and expression of the phenol-soluble modulin (PSM) virulence factors. In the process, we create a viscous fluid that models bacterial behavior in synovial fluid. We suggest that our findings and, by extension, use of this fluid can help to better model bacterial behavior of new antimicrobial therapies, as well as serve as a starting point to study host protein-bacteria interactions characteristic of physiological fluids.
Collapse
Affiliation(s)
- Samantha Knott
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, United States
| | - Dylan Curry
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, United States
| | - Neil Zhao
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, United States
| | - Pallavi Metgud
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, United States
| | - Sana S. Dastgheyb
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, United States
| | - Caroline Purtill
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, United States
| | - Marc Harwood
- Rothman Orthopaedic Institute, Philadelphia, PA, United States
| | - Antonia F. Chen
- Department of Orthopaedic Surgery, Brigham and Women’s Hospital, Boston, PA, United States
| | - Thomas P. Schaer
- Department of Clinical Studies, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA, United States
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Noreen J. Hickok
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, United States
| |
Collapse
|
20
|
Ménard G, Rouillon A, Ghukasyan G, Emily M, Felden B, Donnio PY. Galleria mellonella Larvae as an Infection Model to Investigate sRNA-Mediated Pathogenesis in Staphylococcus aureus. Front Cell Infect Microbiol 2021; 11:631710. [PMID: 33954118 PMCID: PMC8089379 DOI: 10.3389/fcimb.2021.631710] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 03/26/2021] [Indexed: 11/30/2022] Open
Abstract
Small regulatory RNAs (sRNAs) are key players in bacterial regulatory networks. Monitoring their expression inside living colonized or infected organisms is essential for identifying sRNA functions, but few studies have looked at sRNA expression during host infection with bacterial pathogens. Insufficient in vivo studies monitoring sRNA expression attest to the difficulties in collecting such data, we therefore developed a non-mammalian infection model using larval Galleria mellonella to analyze the roles of Staphylococcus aureus sRNAs during larval infection and to quickly determine possible sRNA involvement in staphylococcal virulence before proceeding to more complicated animal testing. We began by using the model to test infected larvae for immunohistochemical evidence of infection as well as host inflammatory responses over time. To monitor sRNA expression during infection, total RNAs were extracted from the larvae and invading bacteria at different time points. The expression profiles of the tested sRNAs were distinct and they fluctuated over time, with expression of both sprD and sprC increased during infection and associated with mortality, while rnaIII expression remained barely detectable over time. A strong correlation was observed between sprD expression and the mortality. To confirm these results, we used sRNA-knockout mutants to investigate sRNA involvement in Staphylococcus aureus pathogenesis, finding that the decrease in death rates is delayed when either sprD or sprC was lacking. These results demonstrate the relevance of this G. mellonella model for investigating the role of sRNAs as transcriptional regulators involved in staphylococcal virulence. This insect model provides a fast and easy method for monitoring sRNA (and mRNA) participation in S. aureus pathogenesis, and can also be used for other human bacterial pathogens.
Collapse
Affiliation(s)
- Guillaume Ménard
- Univ Rennes, CHU Rennes, INSERM, BRM [Bacterial Regulatory RNAs and Medicine], SB2H (service de Bactériologie Hygiène-Hospitalière), UMR_S 1230, F-35000, Rennes, France
| | - Astrid Rouillon
- Univ Rennes, INSERM, BRM (Bacterial Regulatory RNAs and Medicine), UMR_S 1230, F-35000, Rennes, France
| | - Gevorg Ghukasyan
- Univ Rennes, CNRS, INSERM, BIOSIT (Biologie, Santé, Innovation Technologique de Rennes), UMS 3480, US_S018, F-35000, Rennes, France
| | - Mathieu Emily
- Institut Agro, CNRS, Univ Rennes, IRMAR (Institut de recherche Mathématique de Rennes), UMR 6625, F-35000, Rennes, France
| | - Brice Felden
- Univ Rennes, INSERM, BRM (Bacterial Regulatory RNAs and Medicine), UMR_S 1230, F-35000, Rennes, France
| | - Pierre-Yves Donnio
- Univ Rennes, CHU Rennes, INSERM, BRM [Bacterial Regulatory RNAs and Medicine], SB2H (service de Bactériologie Hygiène-Hospitalière), UMR_S 1230, F-35000, Rennes, France
| |
Collapse
|
21
|
Genotypic and Phenotypic Characterization of Staphylococcus aureus Isolates from the Respiratory Tract in Mechanically-Ventilated Patients. Toxins (Basel) 2021; 13:toxins13020122. [PMID: 33562023 PMCID: PMC7915691 DOI: 10.3390/toxins13020122] [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] [Received: 01/26/2021] [Revised: 02/03/2021] [Accepted: 02/03/2021] [Indexed: 12/17/2022] Open
Abstract
Staphylococcus aureus is a commensal and frequent colonizer of the upper respiratory tract. When mechanical ventilation disrupts natural defenses, S. aureus is frequently isolated from the lower airways, but distinguishing between colonization and infection is difficult. The objectives of this study were (1) to investigate the bacterial genome sequence in consecutive isolates in order to identify changes related to the pathological adaptation to the lower respiratory tract and (2) to explore the relationship between specific phenotypic and genotypic features with the patient’s study group, persistence of the clinical isolate and clinical outcome. A set of 94 clinical isolates were selected and corresponded to 34 patients that were classified as having pneumonia (10), tracheobronchitis (11) and bronchial colonization (13). Clinical strains were phenotypically characterized by conventional identification and susceptibility testing methods. Isolates underwent whole genome sequencing using Illumina HiSeq4000. Genotypic characterization was performed with an in-house pipeline (BacterialTyper). Genomic variation arising within-host was determined by comparing mapped sequences and de novo assemblies. Virulence factors important in staphylococcal colonization and infection were characterized using previously established functional assays. (1) Toxin production was assessed using a THP-1 cytotoxicity assay, which reports on the gross cytotoxicity of individual isolates. In addition, we investigated the expression of the major virulence factor, alpha-toxin (Hla) by Western blot. (2) Adhesion to the important extracellular matrix molecule, fibronectin, was determined using a standardized microtitre plate assay. Finally, invasion experiments using THP-1 and A539 cell lines and selected clinical strains were also performed. Repeated isolation of S. aureus from endotracheal aspirate usually reflects persistence of the same strain. Within-host variation is detectable in this setting, but it shows no evidence of pathological adaptation related to virulence, resistance or niche adaptations. Cytotoxicity was variable among isolates with 14 strains showing no cytotoxicity, with these latter presenting an unaltered Fn binding capacity. No changes on cytotoxicity were reported when comparing study groups. Fn binding capacity was reported for almost all strains, with the exception of two strains that presented the lowest values. Strains isolated from patients with pneumonia presented a lower capacity of adhesion in comparison to those isolated during tracheobronchitis (p = 0.002). Hla was detected in 71 strains (75.5%), with most of the producer strains in pneumonia and bronchial colonization group (p = 0.06). In our cohort, Hla expression (presence or absence) in sequential isolates was usually preserved (70%) although in seven cases the expression varied over time. No relationship was found between low cytotoxicity and intracellular persistence in invasion experiments. In our study population, persistent S. aureus isolation from airways in ventilated patients does not reflect pathological adaptation. There is an important diversity of sequence types. Cytotoxicity is variable among strains, but no association with study groups was found, whereas isolates from patients with pneumonia had lower adhesion capability. Favorable clinical outcome correlated with increased bacterial adhesion in vitro. Most of the strains isolated from the lower airways were Hla producers and no correlation with an adverse outcome was reported. The identification of microbial factors that contribute to virulence is relevant to optimize patient management during lower respiratory tract infections.
Collapse
|
22
|
Saeed K, Sendi P, Arnold WV, Bauer TW, Coraça-Huber DC, Chen AF, Choe H, Daiss JL, Ghert M, Hickok NJ, Nishitani K, Springer BD, Stoodley P, Sculco TP, Brause BD, Parvizi J, McLaren AC, Schwarz EM. Bacterial toxins in musculoskeletal infections. J Orthop Res 2021; 39:240-250. [PMID: 32255540 PMCID: PMC7541548 DOI: 10.1002/jor.24683] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 02/27/2020] [Accepted: 04/01/2020] [Indexed: 02/04/2023]
Abstract
Musculoskeletal infections (MSKIs) remain a major health burden in orthopaedics. Bacterial toxins are foundational to pathogenesis in MSKI, but poorly understood by the community of providers that care for patients with MSKI, inducing an international group of microbiologists, infectious diseases specialists, orthopaedic surgeons and biofilm scientists to review the literature in this field to identify key topics and compile the current knowledge on the role of toxins in MSKI, with the goal of illuminating potential impact on biofilm formation and dispersal as well as therapeutic strategies. The group concluded that further research is needed to maximize our understanding of the effect of toxins on MSKIs, including: (i) further research to identify the roles of bacterial toxins in MSKIs, (ii) establish the understanding of the importance of environmental and host factors and in vivo expression of toxins throughout the course of an infection, (iii) establish the principles of drug-ability of antitoxins as antimicrobial agents in MSKIs, (iv) have well-defined metrics of success for antitoxins as antiinfective drugs, (v) design a cocktail of antitoxins against specific pathogens to (a) inhibit biofilm formation and (b) inhibit toxin release. The applicability of antitoxins as potential antimicrobials in the era of rising antibiotic resistance could meet the needs of day-to-day clinicians.
Collapse
Affiliation(s)
- Kordo Saeed
- University Hospital Southampton NHS Foundation Trust, Department of Microbiology, Microbiology Innovation and Research Unit (MIRU), Southampton, UK; and University of Southampton, School of Medicine, Southampton UK
| | - Parham Sendi
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
- Department of Infectious Diseases and Hospital Epidemiology/ Department of Orthopaedics and Traumatology, University Hospital Basel, University Basel, Basel, Switzerland
| | - William V. Arnold
- Department of Orthopaedic Surgery, Rothman Institute at Thomas Jefferson University Hospital, Philadelphia, PA, USA
| | - Thomas W. Bauer
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, Hospital for Special Surgery, New York, NY, USA
| | - Débora C. Coraça-Huber
- Research Laboratory for Implant Associated Infections (Biofilm Lab), Experimental Orthopaedics, Department of Orthopaedic Surgery, Medical University of Innsbruck, Innsbruck, Austria
| | - Antonia F. Chen
- Department of Orthopaedic Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Hyonmin Choe
- Department of Orthopaedic Surgery, Yokohama City University, Yokohama, Kanagawa, Japan
| | - John L. Daiss
- Center for Musculoskeletal Research, School of Medicine and Dentistry University of Rochester, Rochester, NY, USA
| | - Michelle Ghert
- Department of Surgery, Division of Orthopaedic Surgery, McMaster University, Hamilton, ON, Canada
| | - Noreen J. Hickok
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, USA
| | - Kohei Nishitani
- Department of Orthopaedic Surgery, Kyoto University, Kyoto, Japan
| | - Bryan D. Springer
- OrthoCarolina Hip and Knee Center, Atrium Musculoskeletal Institute, Charlotte, NC, USA
| | - Paul Stoodley
- Departments of Microbial Infection and Immunity and OrthopedicsInfectious Diseases Institute, The Ohio State University, 716 Biomedical Research Tower, 460 West 12th Avenue, Columbus OH, Canada
- National Centre for Microbial Tribology at Southampton (nCATS), National Biofilm Innovation Centre (NBIC), Mechanical Engineering, University of Southampton, Southampton, UK.
| | - Thomas P. Sculco
- Department of Orthopaedic Surgery, Weill Cornell Medicine, Hospital for Special Surgery, New York, NY, USA
| | - Barry D. Brause
- Department of Infectious Diseases, Weill Cornell Medicine, Hospital for Special Surgery, New York, NY, USA
| | - Javad Parvizi
- Department of Orthopaedics, Rothman Institute at Thomas Jefferson University Hospital, Philadelphia, PA, USA
| | - Alex C. McLaren
- Department of Orthopaedic Surgery, University of Arizona, College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Edward M. Schwarz
- Center for Musculoskeletal Research, Department of Orthopaedics, University of Rochester, Rochester, NY, USA
| |
Collapse
|
23
|
Huang B, Zhao Z, Zhao Y, Huang S. Protein arginine phosphorylation in organisms. Int J Biol Macromol 2021; 171:414-422. [PMID: 33428953 DOI: 10.1016/j.ijbiomac.2021.01.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 01/04/2021] [Accepted: 01/04/2021] [Indexed: 12/18/2022]
Abstract
Protein arginine phosphorylation (pArg), a novel molecular switch, plays a key role in regulating cellular processes. The intrinsic acid lability, hot sensitivity, and hot-alkali instability of "high-energy" phosphoamidate (PN bond) in pArg, make the investigation highly difficult and challenging. Recently, the progress in identifying prokaryotic protein arginine kinase/phosphatase and assigning hundreds of pArg proteins and phosphosites has been made, which is arousing scientists' interest and passions. It shows that pArg is tightly connected to bacteria stress response and pathogenicity, and is probably implied in human diseases. In this review, we highlight the strategies for investigation of this mysterious modification and its momentous physiological functions, and also prospect for the potentiality of drugs development targeting pArg-relative pathways.
Collapse
Affiliation(s)
- Biling Huang
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, PR China.
| | - Zhixing Zhao
- MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, PR China
| | - Yufen Zhao
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, PR China; Department of Chemical Biology, College of Chemistry and Chemical Engineering, Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiamen 361005, PR China; Key Lab of Bioorganic Phosphorus Chemistry & Chemical Biology, Department of Chemistry, Tsinghua University, Beijing 100084, PR China.
| | - Shaohua Huang
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, PR China.
| |
Collapse
|
24
|
Iversen S, Johannesen TB, Ingham AC, Edslev SM, Tevell S, Månsson E, Nilsdotter-Augustinsson Å, Söderquist B, Stegger M, Andersen PS. Alteration of Bacterial Communities in Anterior Nares and Skin Sites of Patients Undergoing Arthroplasty Surgery: Analysis by 16S rRNA and Staphylococcal-Specific tuf Gene Sequencing. Microorganisms 2020; 8:E1977. [PMID: 33322779 PMCID: PMC7763315 DOI: 10.3390/microorganisms8121977] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/07/2020] [Accepted: 12/08/2020] [Indexed: 12/24/2022] Open
Abstract
The aim was to study alterations of bacterial communities in patients undergoing hip or knee arthroplasty to assess the impact of chlorhexidine gluconate soap decolonisation and systemic antibiotic prophylaxis. A Swedish multicentre, prospective collection of samples obtained from elective arthroplasty patients (n = 83) by swabbing anterior nares, skin sites in the groin and the site of planned surgery, before and after arthroplasty surgery, was analysed by 16S rRNA (V3-V4) gene sequencing and a complementary targeted tuf gene sequencing approach to comprehensively characterise alterations in staphylococcal communities. Significant reductions in alpha diversity was detected for both bacterial (p = 0.04) and staphylococcal (p = 0.03) groin communities after arthroplasty surgery with significant reductions in relative Corynebacterium (p = 0.001) abundance and Staphylococcus hominis (p = 0.01) relative staphylococcal abundance. In nares, significant reductions occurred for Staphylococcus hominis (p = 0.02), Staphylococcus haemolyticus (p = 0.02), and Staphylococcus pasteuri (p = 0.003) relative to other staphylococci. Staphylococcus aureus colonised 35% of anterior nares before and 26% after arthroplasty surgery. Staphylococcus epidermidis was the most abundant staphylococcal species at all sampling sites. No bacterial genus or staphylococcal species increased significantly after arthroplasty surgery. Application of a targeted tuf gene sequencing approach provided auxiliary staphylococcal community profiles and allowed species-level characterisation directly from low biomass clinical samples.
Collapse
Affiliation(s)
- Søren Iversen
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, 2300 Copenhagen, Denmark; (T.B.J.); (A.C.I.); (S.M.E.); (M.S.); (P.S.A.)
| | - Thor Bech Johannesen
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, 2300 Copenhagen, Denmark; (T.B.J.); (A.C.I.); (S.M.E.); (M.S.); (P.S.A.)
| | - Anna Cäcilia Ingham
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, 2300 Copenhagen, Denmark; (T.B.J.); (A.C.I.); (S.M.E.); (M.S.); (P.S.A.)
| | - Sofie Marie Edslev
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, 2300 Copenhagen, Denmark; (T.B.J.); (A.C.I.); (S.M.E.); (M.S.); (P.S.A.)
| | - Staffan Tevell
- Department of Infectious Diseases and Centre for Clinical Research and Education, County Council of Värmland, SE-651 82 Karlstad, Sweden;
- School of Medical Sciences, Faculty of Medicine and Health, Örebro University, SE-701 82 Örebro, Sweden; (E.M.); (B.S.)
| | - Emeli Månsson
- School of Medical Sciences, Faculty of Medicine and Health, Örebro University, SE-701 82 Örebro, Sweden; (E.M.); (B.S.)
- Centre for Clinical Research, Hospital Västmanland, Uppsala University, Region Västmanland, SE‐721 89 Västerås, Sweden
| | - Åsa Nilsdotter-Augustinsson
- Department of Infectious Diseases and Department of Clinical and Biomedical Sciences, Linköping University, SE-581 83 Norrköping, Sweden;
| | - Bo Söderquist
- School of Medical Sciences, Faculty of Medicine and Health, Örebro University, SE-701 82 Örebro, Sweden; (E.M.); (B.S.)
- Department of Laboratory Medicine, Clinical Microbiology, Faculty of Medicine and Health, Örebro University, SE-701 82 Örebro, Sweden
| | - Marc Stegger
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, 2300 Copenhagen, Denmark; (T.B.J.); (A.C.I.); (S.M.E.); (M.S.); (P.S.A.)
- School of Medical Sciences, Faculty of Medicine and Health, Örebro University, SE-701 82 Örebro, Sweden; (E.M.); (B.S.)
| | - Paal Skytt Andersen
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, 2300 Copenhagen, Denmark; (T.B.J.); (A.C.I.); (S.M.E.); (M.S.); (P.S.A.)
| |
Collapse
|
25
|
Silence as a way of niche adaptation: mecC-MRSA with variations in the accessory gene regulator (agr) functionality express kaleidoscopic phenotypes. Sci Rep 2020; 10:14787. [PMID: 32901059 PMCID: PMC7479134 DOI: 10.1038/s41598-020-71640-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 08/19/2020] [Indexed: 11/09/2022] Open
Abstract
Functionality of the accessory gene regulator (agr) quorum sensing system is an important factor promoting either acute or chronic infections by the notorious opportunistic human and veterinary pathogen Staphylococcus aureus. Spontaneous alterations of the agr system are known to frequently occur in human healthcare-associated S. aureus lineages. However, data on agr integrity and function are sparse regarding other major clonal lineages. Here we report on the agr system functionality and activity level in mecC-carrying methicillin resistant S. aureus (MRSA) of various animal origins (n = 33) obtained in Europe as well as in closely related human isolates (n = 12). Whole genome analysis assigned all isolates to four clonal complexes (CC) with distinct agr types (CC599 agr I, CC49 agr II, CC130 agr III and CC1943 agr IV). Agr functionality was assessed by a combination of phenotypic assays and proteome analysis. In each CC, isolates with varying agr activity levels were detected, including the presence of completely non-functional variants. Genomic comparison of the agr I-IV encoding regions associated these phenotypic differences with variations in the agrA and agrC genes. The genomic changes were detected independently in divergent lineages, suggesting that agr variation might foster viability and adaptation of emerging MRSA lineages to distinct ecological niches.
Collapse
|
26
|
Acapsular Staphylococcus aureus with a non-functional agr regains capsule expression after passage through the bloodstream in a bacteremia mouse model. Sci Rep 2020; 10:14108. [PMID: 32839485 PMCID: PMC7445255 DOI: 10.1038/s41598-020-70671-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 07/23/2020] [Indexed: 01/18/2023] Open
Abstract
Selection pressures exerted on Staphylococcus aureus by host factors during infection may lead to the emergence of regulatory phenotypes better adapted to the infection site. Traits convenient for persistence may be fixed by mutation thus turning these mutants into microevolution endpoints. The feasibility that stable, non-encapsulated S. aureus mutants can regain expression of key virulence factors for survival in the bloodstream was investigated. S. aureus agr mutant HU-14 (IS256 insertion in agrC) from a patient with chronic osteomyelitis was passed through the bloodstream using a bacteriemia mouse model and derivative P3.1 was obtained. Although IS256 remained inserted in agrC, P3.1 regained production of capsular polysaccharide type 5 (CP5) and staphyloxanthin. Furthermore, P3.1 expressed higher levels of asp23/SigB when compared with parental strain HU-14. Strain P3.1 displayed decreased osteoclastogenesis capacity, thus indicating decreased adaptability to bone compared with strain HU-14 and exhibited a trend to be more virulent than parental strain HU-14. Strain P3.1 exhibited the loss of one IS256 copy, which was originally located in the HU-14 noncoding region between dnaG (DNA primase) and rpoD (sigA). This loss may be associated with the observed phenotype change but the mechanism remains unknown. In conclusion, S. aureus organisms that escape the infected bone may recover the expression of key virulence factors through a rapid microevolution pathway involving SigB regulation of key virulence factors.
Collapse
|
27
|
Palma Medina LM, Becker AK, Michalik S, Surmann K, Hildebrandt P, Gesell Salazar M, Mekonnen SA, Kaderali L, Völker U, van Dijl JM. Interaction of Staphylococcus aureus and Host Cells upon Infection of Bronchial Epithelium during Different Stages of Regeneration. ACS Infect Dis 2020; 6:2279-2290. [PMID: 32579327 PMCID: PMC7432605 DOI: 10.1021/acsinfecdis.0c00403] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
![]()
The
primary barrier that protects our lungs against infection by
pathogens is a tightly sealed layer of epithelial cells. When the
integrity of this barrier is disrupted as a consequence of chronic
pulmonary diseases or viral insults, bacterial pathogens will gain
access to underlying tissues. A major pathogen that can take advantage
of such conditions is Staphylococcus aureus, thereby
causing severe pneumonia. In this study, we investigated how S. aureus responds to different conditions of the human
epithelium, especially nonpolarization and fibrogenesis during regeneration
using an in vitro infection model. The infective
process was monitored by quantification of the epithelial cell and
bacterial populations, fluorescence microscopy, and mass spectrometry.
The results uncover differences in bacterial internalization and population
dynamics that correlate with the outcome of infection. Protein profiling
reveals that, irrespective of the polarization state of the epithelial
cells, the invading bacteria mount similar responses to adapt to the
intracellular milieu. Remarkably, a bacterial adaptation that was
associated with the regeneration state of the epithelial cells concerned
the early upregulation of proteins controlled by the redox-responsive
regulator Rex when bacteria were confronted with a polarized cell
layer. This is indicative of the modulation of the bacterial cytoplasmic
redox state to maintain homeostasis early during infection even before
internalization. Our present observations provide a deeper insight
into how S. aureus can take advantage of a breached
epithelial barrier and show that infected epithelial cells have limited
ability to respond adequately to staphylococcal insults.
Collapse
Affiliation(s)
- Laura M. Palma Medina
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17475 Greifswald, Germany
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, 9700 RB Groningen, The Netherlands
| | - Ann-Kristin Becker
- Institute of Bioinformatics, University Medicine Greifswald, 17475 Greifswald, Germany
| | - Stephan Michalik
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17475 Greifswald, Germany
| | - Kristin Surmann
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17475 Greifswald, Germany
| | - Petra Hildebrandt
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17475 Greifswald, Germany
| | - Manuela Gesell Salazar
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17475 Greifswald, Germany
| | - Solomon A. Mekonnen
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17475 Greifswald, Germany
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, 9700 RB Groningen, The Netherlands
| | - Lars Kaderali
- Institute of Bioinformatics, University Medicine Greifswald, 17475 Greifswald, Germany
| | - Uwe Völker
- Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17475 Greifswald, Germany
| | - Jan Maarten van Dijl
- University of Groningen, University Medical Center Groningen, Department of Medical Microbiology, 9700 RB Groningen, The Netherlands
| |
Collapse
|
28
|
Revealing 29 sets of independently modulated genes in Staphylococcus aureus, their regulators, and role in key physiological response. Proc Natl Acad Sci U S A 2020; 117:17228-17239. [PMID: 32616573 PMCID: PMC7382225 DOI: 10.1073/pnas.2008413117] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Staphylococcus aureus infections impose an immense burden on the healthcare system. To establish a successful infection in a hostile host environment, S. aureus must coordinate its gene expression to respond to a wide array of challenges. This balancing act is largely orchestrated by the transcriptional regulatory network. Here, we present a model of 29 independently modulated sets of genes that form the basis for a segment of the transcriptional regulatory network in clinical USA300 strains of S. aureus. Using this model, we demonstrate the concerted role of various cellular systems (e.g., metabolism, virulence, and stress response) underlying key physiological responses, including response during blood infection. The ability of Staphylococcus aureus to infect many different tissue sites is enabled, in part, by its transcriptional regulatory network (TRN) that coordinates its gene expression to respond to different environments. We elucidated the organization and activity of this TRN by applying independent component analysis to a compendium of 108 RNA-sequencing expression profiles from two S. aureus clinical strains (TCH1516 and LAC). ICA decomposed the S. aureus transcriptome into 29 independently modulated sets of genes (i-modulons) that revealed: 1) High confidence associations between 21 i-modulons and known regulators; 2) an association between an i-modulon and σS, whose regulatory role was previously undefined; 3) the regulatory organization of 65 virulence factors in the form of three i-modulons associated with AgrR, SaeR, and Vim-3; 4) the roles of three key transcription factors (CodY, Fur, and CcpA) in coordinating the metabolic and regulatory networks; and 5) a low-dimensional representation, involving the function of few transcription factors of changes in gene expression between two laboratory media (RPMI, cation adjust Mueller Hinton broth) and two physiological media (blood and serum). This representation of the TRN covers 842 genes representing 76% of the variance in gene expression that provides a quantitative reconstruction of transcriptional modules in S. aureus, and a platform enabling its full elucidation.
Collapse
|
29
|
Abstract
In the 1980s, menstrual toxic shock syndrome (mTSS) became a household topic, particularly among mothers and their daughters. The research performed at the time, and for the first time, exposed the American public as well as the biomedical community, in a major way, to understanding disease progression and investigation. Those studies led to the identification of the cause, Staphylococcus aureus and the pyrogenic toxin superantigen TSS toxin 1 (TSST-1), and many of the risk factors, for example, tampon use. Those studies in turn led to TSS warning labels on the outside and inside of tampon boxes and, as important, uniform standards worldwide of tampon absorbency labeling. This review addresses our understanding of the development and conclusions related to mTSS and risk factors. We leave the final message that even though mTSS is not commonly in the news today, cases continue to occur. Additionally, S. aureus strains cycle in human populations in roughly 10-year intervals, possibly dependent on immune status. TSST-1-producing S. aureus bacteria appear to be reemerging, suggesting that physician awareness of this emergence and mTSS history should be heightened.
Collapse
|
30
|
Lacoma A, Usón L, Mendoza G, Sebastián V, Garcia-Garcia E, Muriel-Moreno B, Domínguez J, Arruebo M, Prat C. Novel intracellular antibiotic delivery system against Staphylococcus aureus: cloxacillin-loaded poly(d,l-lactide-co-glycolide) acid nanoparticles. Nanomedicine (Lond) 2020; 15:1189-1203. [DOI: 10.2217/nnm-2019-0371] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Aim: First, to compare in vitro minimum inhibitory concentrations (MIC) of free cloxacillin and cloxacillin-containing nanoparticles (NP) against methicillin-susceptible (MSSA) and resistant Staphylococcus aureus (MRSA) and second, to assess NP antimicrobial activity against intracellular S. aureus. Methods: Poly(d,l-lactide-co-glycolide) acid (PLGA)-NP were loaded with cloxacillin and physico-chemically characterized. MICs were determined for reference strains Newman-(MSSA) and USA300-(MRSA). Murine alveolar macrophages were infected, and bacterial intracellular survival was assessed after incubating with free-cloxacillin or PLGA-cloxacillin-NP. Results & conclusion: For both isolates, MICs for antibiotic-loaded-NP were lower than those obtained with free cloxacillin, indicating that the drug encapsulation improves antimicrobial activity. A sustained antibiotic release was demonstrated when using the PLGA-cloxacillin-NP. When considering the lowest concentrations, the use of drug-loaded NP enabled a higher reduction of intracellular bacterial load.
Collapse
Affiliation(s)
- Alicia Lacoma
- Microbiology Department, Hospital Universitari Germans Trias i Pujol, Fundació Institut d’Investigació en Ciències de la Salut GermansTrias i Pujol, Universitat Autònoma de Barcelona, Badalona, Spain
- CIBER Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Spain
| | - Laura Usón
- Institute of Nanoscience of Aragon (INA), Department of Chemical Engineering & Environmental Technologies, University of Zaragoza & Instituto de Ciencia de Materiales de Aragón (ICMA), Universidad de Zaragoza-CSIC, 50018, Zaragoza, Spain
- CIBER Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Instituto de Salud Carlos III, Spain
| | - Gracia Mendoza
- Institute of Nanoscience of Aragon (INA), Department of Chemical Engineering & Environmental Technologies, University of Zaragoza & Instituto de Ciencia de Materiales de Aragón (ICMA), Universidad de Zaragoza-CSIC, 50018, Zaragoza, Spain
- CIBER Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Instituto de Salud Carlos III, Spain
| | - Victor Sebastián
- Institute of Nanoscience of Aragon (INA), Department of Chemical Engineering & Environmental Technologies, University of Zaragoza & Instituto de Ciencia de Materiales de Aragón (ICMA), Universidad de Zaragoza-CSIC, 50018, Zaragoza, Spain
- CIBER Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Instituto de Salud Carlos III, Spain
| | - Esther Garcia-Garcia
- Microbiology Department, Hospital Universitari Germans Trias i Pujol, Fundació Institut d’Investigació en Ciències de la Salut GermansTrias i Pujol, Universitat Autònoma de Barcelona, Badalona, Spain
| | - Beatriz Muriel-Moreno
- Microbiology Department, Hospital Universitari Germans Trias i Pujol, Fundació Institut d’Investigació en Ciències de la Salut GermansTrias i Pujol, Universitat Autònoma de Barcelona, Badalona, Spain
| | - Jose Domínguez
- Microbiology Department, Hospital Universitari Germans Trias i Pujol, Fundació Institut d’Investigació en Ciències de la Salut GermansTrias i Pujol, Universitat Autònoma de Barcelona, Badalona, Spain
- CIBER Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Spain
| | - Manuel Arruebo
- Institute of Nanoscience of Aragon (INA), Department of Chemical Engineering & Environmental Technologies, University of Zaragoza & Instituto de Ciencia de Materiales de Aragón (ICMA), Universidad de Zaragoza-CSIC, 50018, Zaragoza, Spain
- CIBER Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Instituto de Salud Carlos III, Spain
| | - Cristina Prat
- Microbiology Department, Hospital Universitari Germans Trias i Pujol, Fundació Institut d’Investigació en Ciències de la Salut GermansTrias i Pujol, Universitat Autònoma de Barcelona, Badalona, Spain
- CIBER Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Spain
- Julius Centre for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| |
Collapse
|
31
|
Gaidar D, Jonas A, Akulenko R, Ruffing U, Herrmann M, Helms V, von Müller L. Analysis of the dynamics of Staphylococcus aureus binding to white blood cells using whole blood assay and geno-to-pheno mapping. Int J Med Microbiol 2020; 310:151411. [DOI: 10.1016/j.ijmm.2020.151411] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 12/02/2019] [Accepted: 02/03/2020] [Indexed: 12/28/2022] Open
|
32
|
The Staphylococcus aureus Cystine Transporters TcyABC and TcyP Facilitate Nutrient Sulfur Acquisition during Infection. Infect Immun 2020; 88:IAI.00690-19. [PMID: 31843961 DOI: 10.1128/iai.00690-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 12/06/2019] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus is a significant human pathogen due to its capacity to cause a multitude of diseases. As such, S. aureus efficiently pillages vital nutrients from the host; however, the molecular mechanisms that support sulfur acquisition during infection have not been established. One of the most abundant extracellular sulfur-containing metabolites within the host is cysteine, which acts as the major redox buffer in the blood by transitioning between reduced and oxidized (cystine) forms. We therefore hypothesized that S. aureus acquires host-derived cysteine and cystine as sources of nutrient sulfur during systemic infection. To test this hypothesis, we used the toxic cystine analogue selenocystine to initially characterize S. aureus homologues of the Bacillus subtilis cystine transporters TcyABC and TcyP. We found that genetic inactivation of both TcyA and TcyP induced selenocystine resistance. The double mutant also failed to proliferate in medium supplemented with cystine, cysteine, or N-acetyl cysteine as the sole sulfur source. However, only TcyABC was necessary for proliferation in defined medium containing homocystine as the sulfur source. Using a murine model of systemic infection, we observed tcyP-dependent competitive defects in the liver and heart, indicating that this sulfur acquisition strategy supports proliferation of S. aureus in these organs. Phylogenetic analyses identified TcyP homologues in many pathogenic species, implying that this sulfur procurement strategy is conserved. In total, this study is the first to experimentally validate sulfur acquisition systems in S. aureus and establish their importance during pathogenesis.
Collapse
|
33
|
Mairi A, Touati A, Lavigne JP. Methicillin-Resistant Staphylococcus aureus ST80 Clone: A Systematic Review. Toxins (Basel) 2020; 12:toxins12020119. [PMID: 32075074 PMCID: PMC7076798 DOI: 10.3390/toxins12020119] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 02/05/2020] [Accepted: 02/11/2020] [Indexed: 01/09/2023] Open
Abstract
This review assessed the molecular characterization of the methicillin-resistant Staphylococcus aureus (MRSA)-ST80 clone with an emphasis on its proportion of total MRSA strains isolated, PVL production, spa-typing, antibiotic resistance, and virulence. A systematic review of the literature was conducted on MRSA-ST80 clone published between 1 January 2000 and 31 August 2019. Citations were chosen for a review of the full text if we found evidence that MRSA-ST80 clone was reported in the study. For each isolate, the country of isolation, the sampling period, the source of isolation (the type of infection, nasal swabs, or extra-human), the total number of MRSA strains isolated, number of MRSA-ST80 strains, antibiotic resistance patterns, PVL production, virulence genes, and spa type were recorded. The data from 103 articles were abstracted into an Excel database. Analysis of the data showed that the overall proportion of MRSA-ST80 has been decreasing in many countries in recent years. The majority of MRSA-ST80 were PVL positive with spa-type t044. Only six reports of MRSA-ST80 in extra-human niches were found. This review summarizes the rise of MRSA-ST80 and the evidence that suggests that it could be in decline in many countries.
Collapse
Affiliation(s)
- Assia Mairi
- Laboratoire d’Ecologie Microbienne, FSNV, Université de Bejaia, Bejaia 06000, Algeria; (A.M.); (A.T.)
| | - Abdelaziz Touati
- Laboratoire d’Ecologie Microbienne, FSNV, Université de Bejaia, Bejaia 06000, Algeria; (A.M.); (A.T.)
| | - Jean-Philippe Lavigne
- VBMI, INSERM U1047, Université de Montpellier, Service de Microbiologie et Hygiène Hospitalière, CHU Nîmes, 30029 Nîmes, France
- Correspondence: ; Tel.: +33-4666-832-02
| |
Collapse
|
34
|
Nguyen L, Lu P, Boehm D, Bourke P, Gilmore BF, Hickok NJ, Freeman TA. Cold atmospheric plasma is a viable solution for treating orthopedic infection: a review. Biol Chem 2019; 400:77-86. [PMID: 30138104 DOI: 10.1515/hsz-2018-0235] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 08/06/2018] [Indexed: 12/15/2022]
Abstract
Bacterial infection and antibiotic resistance are major threats to human health and very few solutions are available to combat this eventuality. A growing number of studies indicate that cold (non-thermal) plasma treatment can be used to prevent or eliminate infection from bacteria, bacterial biofilms, fungi and viruses. Mechanistically, a cold plasma discharge is composed of high-energy electrons that generate short-lived reactive oxygen and nitrogen species which further react to form more stable compounds (NO2, H2O2, NH2Cl and others) depending on the gas mixture and plasma parameters. Cold plasma devices are being developed for medical applications including infection, cancer, plastic surgery applications and more. Thus, in this review we explore the potential utility of cold plasma as a non-antibiotic approach for treating post-surgical orthopedic infections.
Collapse
Affiliation(s)
- Ly Nguyen
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, 1015 Walnut Street, Philadelphia, PA 19107-5099, USA
| | - Peng Lu
- College of Science and Health, Dublin Institute of Technology, Dublin, Ireland
| | - Daniela Boehm
- College of Science and Health, Dublin Institute of Technology, Dublin, Ireland
| | - Paula Bourke
- College of Science and Health, Dublin Institute of Technology, Dublin, Ireland
| | - Brendan F Gilmore
- School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Noreen J Hickok
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, 1015 Walnut Street, Philadelphia, PA 19107-5099, USA
| | - Theresa A Freeman
- Department of Orthopaedic Surgery, Sidney Kimmel Medical College, Thomas Jefferson University, 1015 Walnut Street, Philadelphia, PA 19107-5099, USA
| |
Collapse
|
35
|
Artificial Selection for Pathogenicity Mutations in Staphylococcus aureus Identifies Novel Factors Relevant to Chronic Infection. Infect Immun 2019; 87:IAI.00884-18. [PMID: 30642903 DOI: 10.1128/iai.00884-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 01/10/2019] [Indexed: 02/06/2023] Open
Abstract
Adaptation of Staphylococcus aureus to host microenvironments during chronic infection involves spontaneous mutations, yet changes underlying adaptive phenotypes remain incompletely explored. Here, we employed artificial selection and whole-genome sequencing to better characterize spontaneous chromosomal mutations that alter two pathogenicity phenotypes relevant to chronic infection in S. aureus: intracellular invasiveness and intracellular cytotoxicity. We identified 23 genes whose alteration coincided with enhanced virulence, 11 that were previously known and 12 (52%) that had no previously described role in S. aureus pathogenicity. Using precision genome editing, transposon mutants, and gene complementation, we empirically assessed the contributions of individual genes to the two virulence phenotypes. We functionally validated 14 of 21 genes tested as measurably influencing invasion and/or cytotoxicity, including 8 newly implicated by this study. We identified inactivating mutations (murA, ndhC, and a hypothetical membrane protein) and gain-of-function mutations (aroE Thr182Ile, yhcF Thr74Ile, and Asp486Glu in a hypothetical peptidase) in previously unrecognized S. aureus virulence genes that enhance pathogenesis when introduced into a clean genetic background, as well as a novel activating mutation in the known virulence regulator gene saeS (Ala106Thr). Investigation of potentially epistatic interactions identified a tufA mutation (Ala271Val) that enhances virulence only in the context of purine operon repressor gene (purR) inactivation. This project reveals a functionally diverse range of genes affected by gain- or loss-of-function mutations that contribute to S. aureus adaptive virulence phenotypes. More generally, the work establishes artificial selection as a means to determine the genetic mechanisms underlying complex bacterial phenotypes relevant to adaptation during infection.
Collapse
|
36
|
Chromatographic Analyses, In Vitro Biological Activities, and Cytotoxicity of Cannabis sativa L. Essential Oil: A Multidisciplinary Study. Molecules 2018; 23:molecules23123266. [PMID: 30544765 PMCID: PMC6320915 DOI: 10.3390/molecules23123266] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 12/06/2018] [Accepted: 12/08/2018] [Indexed: 01/01/2023] Open
Abstract
Due to renewed interest in the cultivation and production of Italian Cannabis sativa L., we proposed a multi-methodological approach to explore chemically and biologically both the essential oil and the aromatic water of this plant. We reported the chemical composition in terms of cannabinoid content, volatile component, phenolic and flavonoid pattern, and color characteristics. Then, we demonstrated the ethnopharmacological relevance of this plant cultivated in Italy as a source of antioxidant compounds toward a large panel of enzymes (pancreatic lipase, α-amylase, α-glucosidase, and cholinesterases) and selected clinically relevant, multidrug-sensible, and multidrug-resistant microbial strains (Staphylococcus aureus, Helicobacter pylori, Candida, and Malassezia spp.), evaluating the cytotoxic effects against normal and malignant cell lines. Preliminary in vivo cytotoxicity was also performed on Galleria mellonella larvae. The results corroborate the use of this natural product as a rich source of important biologically active molecules with particular emphasis on the role exerted by naringenin, one of the most important secondary metabolites.
Collapse
|
37
|
Junker S, Maaß S, Otto A, Hecker M, Becher D. Toward the Quantitative Characterization of Arginine Phosphorylations in Staphylococcus aureus. J Proteome Res 2018; 18:265-279. [PMID: 30358407 DOI: 10.1021/acs.jproteome.8b00579] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The Gram-positive bacterium Staphylococcus aureus plays an important role as an opportunistic pathogen and causative agent of nosocomial infections. As pathophysiological research gained insights into host-specific adaptation and a broad range of virulence mechanisms, S. aureus evolved as a model organism for human pathogens. Hence the investigation of staphylococcal proteome expression and regulation supports the understanding of the pathogenicity and relevant physiology of this organism. This study focused on the analysis of protein regulation by reversible protein phosphorylation, in particular, on arginine residues. Therefore, both proteome and phosphoproteome of S. aureus COL wild type were compared with the arginine phosphatase deletion mutant S. aureus COL ΔptpB under control and stress conditions in a quantitative manner. A gel-free approach, adapted to the special challenges of arginine phosphorylations, was applied to analyze the phosphoproteome of exponential growing cells after oxidative stress caused by sublethal concentrations of H2O2. Together with phenotypic characterization of S. aureus COL ΔptpB, this study disclosed first insights into the physiological role of arginine phosphorylations in Gram-positive pathogens. A spectral library based quantification of phosphopeptides finally allowed us to link arginine phosphorylation to staphylococcal oxidative stress response, amino acid metabolism, and virulence.
Collapse
Affiliation(s)
- Sabryna Junker
- Institute for Microbiology , University of Greifswald , Greifswald 17487 , Germany
| | - Sandra Maaß
- Institute for Microbiology , University of Greifswald , Greifswald 17487 , Germany
| | - Andreas Otto
- Institute for Microbiology , University of Greifswald , Greifswald 17487 , Germany
| | - Michael Hecker
- Institute for Microbiology , University of Greifswald , Greifswald 17487 , Germany
| | - Dörte Becher
- Institute for Microbiology , University of Greifswald , Greifswald 17487 , Germany
| |
Collapse
|
38
|
PhoPR Contributes to Staphylococcus aureus Growth during Phosphate Starvation and Pathogenesis in an Environment-Specific Manner. Infect Immun 2018; 86:IAI.00371-18. [PMID: 30061377 DOI: 10.1128/iai.00371-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 07/21/2018] [Indexed: 12/31/2022] Open
Abstract
Microbial pathogens must obtain all essential nutrients, including phosphate, from the host. To optimize phosphate acquisition in diverse and dynamic environments, such as mammalian tissues, many bacteria use the PhoPR two-component system. Despite the necessity of this system for virulence in several species, PhoPR has not been studied in the major human pathogen Staphylococcus aureus To illuminate its role in staphylococcal physiology, we initially assessed whether PhoPR controls the expression of the three inorganic phosphate (Pi) importers (PstSCAB, NptA, and PitA) in S. aureus This analysis revealed that PhoPR is required for the expression of pstSCAB and nptA and can modulate pitA expression. Consistent with a role in phosphate homeostasis, PhoPR-mediated regulation of the transporters is influenced by phosphate availability. Further investigations revealed that PhoPR is necessary for growth under Pi-limiting conditions, and in some environments, its primary role is to induce the expression of pstSCAB or nptA Interestingly, in other environments, PhoPR is necessary for growth independent of Pi transporter expression, indicating that additional PhoPR-regulated factors promote S. aureus adaptation to low-Pi conditions. Together, these data suggest that PhoPR differentially contributes to growth in an environment-specific manner. In a systemic infection model, a mutant of S. aureus lacking PhoPR is highly attenuated. Further investigation revealed that PhoPR-regulated factors, in addition to Pi transporters, are critical for staphylococcal pathogenesis. Cumulatively, these findings point to an important role for PhoPR in orchestrating Pi acquisition as well as transporter-independent mechanisms that contribute to S. aureus virulence.
Collapse
|
39
|
Suligoy CM, Lattar SM, Noto Llana M, González CD, Alvarez LP, Robinson DA, Gómez MI, Buzzola FR, Sordelli DO. Mutation of Agr Is Associated with the Adaptation of Staphylococcus aureus to the Host during Chronic Osteomyelitis. Front Cell Infect Microbiol 2018; 8:18. [PMID: 29456969 PMCID: PMC5801681 DOI: 10.3389/fcimb.2018.00018] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Accepted: 01/12/2018] [Indexed: 11/13/2022] Open
Abstract
Selection pressures exerted on Staphylococcus aureus by host factors may lead to the emergence of mutants better adapted to the evolving conditions at the infection site. This study was aimed at identifying the changes that occur in S. aureus exposed to the host defense mechanisms during chronic osteomyelitis and evaluating whether these changes affect the virulence of the organism. Genome assessment of two S. aureus isolates collected 13 months apart (HU-85a and HU-85c) from a host with chronic osteomyelitis was made by whole genome sequencing. Agr functionality was assessed by qRT-PCR. Isolates were tested in a rat model of osteomyelitis and the bacterial load (CFU/tibia) and the morphometric osteomyelitic index (OI) were determined. The ability of the isolates to trigger the release of proinflammatory cytokines was determined on macrophages in culture. Persistence of S. aureus within the host resulted in an agrC frameshift mutation that likely led to the observed phenotype. The capacity to cause bone tissue damage and trigger proinflammatory cytokines by macrophages of the agr-deficient, unencapsulated derivative (HU-85c) was decreased when compared with those of the isogenic CP8-capsulated parental strain (HU-85a). By comparison, no significant differences were found in the bacterial load or the OI from rats challenged with isogenic Reynolds strains [CP5, CP8, and non-typeable (NT)], indicating that lack of CP expression alone was not likely responsible for the reduced capacity to cause tissue damage in HU-85c compared with HU-85a. The production of biofilm was significantly increased in the isogenic derivative HU-85c. Lack of agr-dependent factors makes S. aureus less virulent during chronic osteomyelitis and alteration of the agr functionality seems to permit better adaptation of S. aureus to the chronically infected host.
Collapse
Affiliation(s)
- Carlos M Suligoy
- Instituto de Investigaciones en Microbiología y Parasitología Médica, University of Buenos Aires - CONICET, Buenos Aires, Argentina
| | - Santiago M Lattar
- Instituto de Investigaciones en Microbiología y Parasitología Médica, University of Buenos Aires - CONICET, Buenos Aires, Argentina
| | - Mariángeles Noto Llana
- Instituto de Investigaciones en Microbiología y Parasitología Médica, University of Buenos Aires - CONICET, Buenos Aires, Argentina
| | - Cintia D González
- Instituto de Investigaciones en Microbiología y Parasitología Médica, University of Buenos Aires - CONICET, Buenos Aires, Argentina
| | - Lucía P Alvarez
- Instituto de Investigaciones en Microbiología y Parasitología Médica, University of Buenos Aires - CONICET, Buenos Aires, Argentina
| | - D Ashley Robinson
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, MS, United States
| | - Marisa I Gómez
- Instituto de Investigaciones en Microbiología y Parasitología Médica, University of Buenos Aires - CONICET, Buenos Aires, Argentina
| | - Fernanda R Buzzola
- Instituto de Investigaciones en Microbiología y Parasitología Médica, University of Buenos Aires - CONICET, Buenos Aires, Argentina
| | - Daniel O Sordelli
- Instituto de Investigaciones en Microbiología y Parasitología Médica, University of Buenos Aires - CONICET, Buenos Aires, Argentina
| |
Collapse
|
40
|
Hickok NJ, Shapiro IM, Chen AF. The Impact of Incorporating Antimicrobials into Implant Surfaces. J Dent Res 2017; 97:14-22. [PMID: 28922615 DOI: 10.1177/0022034517731768] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
With the increase in numbers of joint replacements, spinal surgeries, and dental implantations, there is an urgent need to combat implant-associated infection. In addition to stringent sterile techniques, an efficacious way to prevent this destructive complication is to create new implants with antimicrobial properties. Specifically, these implants must be active in the dental implant environment where the implant is bathed in the glycoprotein-rich salivary fluids that enhance bacterial adhesion, and propagation, and biofilm formation. However, in designing an antimicrobial surface, a balance must be struck between antimicrobial activity and the need for the implant to interact with the bone environment. Three types of surfaces have been designed to combat biofilm formation, while attempting to maintain osseous interactions: 1) structured surfaces where topography, usually at the nanoscale, decreases bacterial adhesion sufficiently to retard establishment of infection; 2) surfaces that actively elute antimicrobials to avert bacterial adhesion and promote killing; and 3) surfaces containing permanently bonded agents that generate antimicrobial surfaces that prevent long-term bacterial adhesion. Both topographical and elution surfaces exhibit varying, albeit limited, antimicrobial activity in vitro. With respect to covalent coupling, we present studies on the ability of the permanent antimicrobial surfaces to kill organisms while fostering osseointegration. All approaches have significant drawbacks with respect to stability and efficacy, but the permanent surfaces may have an edge in creating a long-term antibacterial environment.
Collapse
Affiliation(s)
- N J Hickok
- 1 Department of Orthopaedic Surgery, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, USA
| | - I M Shapiro
- 1 Department of Orthopaedic Surgery, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, USA
| | - A F Chen
- 1 Department of Orthopaedic Surgery, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, USA.,2 The Rothman Institute, Philadelphia, PA, USA
| |
Collapse
|
41
|
Prat C, Lacoma A. Bacteria in the respiratory tract-how to treat? Or do not treat? Int J Infect Dis 2017; 51:113-122. [PMID: 27776777 DOI: 10.1016/j.ijid.2016.09.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 08/30/2016] [Accepted: 09/04/2016] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Acute and chronic respiratory tract infections are a common cause of inappropriate antimicrobial prescription. Antimicrobial therapy leads to the development of resistance and the emergence of opportunistic pathogens that substitute the indigenous microbiota. METHODS This review explores the major challenges and lines of research to adequately establish the clinical role of bacteria and the indications for antimicrobial treatment, and reviews novel therapeutic approaches. RESULTS In patients with chronic pulmonary diseases and structural disturbances of the bronchial tree or the lung parenchyma, clinical and radiographic signs and symptoms are almost constantly present, including a basal inflammatory response. Bacterial adaptative changes and differential phenotypes are described, depending on the clinical role and niche occupied. The respiratory tract has areas that are potentially inaccessible to antimicrobials. Novel therapeutic approaches include new ways of administering antimicrobials that may allow intracellular delivery or delivery across biofilms, targeting the functions essential for infection, such as regulatory systems, or the virulence factors required to cause host damage and disease. Alternatives to antibiotics and antimicrobial adjuvants are under development. CONCLUSIONS Prudent treatment, novel targets, and improved drug delivery systems will contribute to reduce the emergence of antimicrobial resistance in lower respiratory tract infections.
Collapse
Affiliation(s)
- Cristina Prat
- Microbiology Department, Hospital Universitari Germans Trias i Pujol, Institut d'Investigació Germans Trias i Pujol, Universitat Autònoma de Barcelona, Ctra del Canyet s/n, 08916 Badalona, Barcelona, Spain; CIBER Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain.
| | - Alicia Lacoma
- Microbiology Department, Hospital Universitari Germans Trias i Pujol, Institut d'Investigació Germans Trias i Pujol, Universitat Autònoma de Barcelona, Ctra del Canyet s/n, 08916 Badalona, Barcelona, Spain; CIBER Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain
| |
Collapse
|
42
|
Nostro A, Marino A, Ginestra G, Cellini L, Di Giulio M, Bisignano G. Effects of adaptation to carvacrol on Staphylococcus aureus in the planktonic and biofilm phases. BIOFOULING 2017; 33:470-480. [PMID: 28521511 DOI: 10.1080/08927014.2017.1323080] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 04/19/2017] [Indexed: 06/07/2023]
Abstract
The effect of exposure to sub-minimum inhibitory concentrations of carvacrol, for either 3-10 days, on direct (carvacrol) or cross-protection (cinnamaldehyde, eugenol, antibiotics) and the influence on planktonic and biofilm growth of four Staphylococcus aureus strains were reported. The sequential exposure to carvacrol resulted in a direct protection that was more evident in two of the four strains after 10 days. No significant cross-protection against cinnamaldehyde, eugenol and antibiotics was detected. An adaptive response was associated with a prolonged lag phase, a lower yield of bacteria, a colony phenotype likely to be associated to small colony variants and an increase in biofilm production. Generally, the biofilm of the adapted strains was less susceptible to subMICs of carvacrol compared to the biofilms of non-adapted strains. In contrast, it was demonstrated that in the case of mature biofilms the susceptibility was similar. The exposure of S. aureus to carvacrol at concentrations above the MIC resulted in a very low mutation frequency.
Collapse
Affiliation(s)
- Antonia Nostro
- a Department of Chemical, Biological, Pharmaceutical and Environmental Sciences , University of Messina , Messina , Italy
| | - Andreana Marino
- a Department of Chemical, Biological, Pharmaceutical and Environmental Sciences , University of Messina , Messina , Italy
| | - Giovanna Ginestra
- a Department of Chemical, Biological, Pharmaceutical and Environmental Sciences , University of Messina , Messina , Italy
| | - Luigina Cellini
- b Department of Pharmacy , University "G. d'Annunzio" Chieti-Pescara , Chieti , Italy
| | - Mara Di Giulio
- b Department of Pharmacy , University "G. d'Annunzio" Chieti-Pescara , Chieti , Italy
| | - Giuseppe Bisignano
- a Department of Chemical, Biological, Pharmaceutical and Environmental Sciences , University of Messina , Messina , Italy
| |
Collapse
|
43
|
Metabolic shift in the emergence of hyperinvasive pandemic meningococcal lineages. Sci Rep 2017; 7:41126. [PMID: 28112239 PMCID: PMC5282872 DOI: 10.1038/srep41126] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 12/15/2016] [Indexed: 12/15/2022] Open
Abstract
Hyperinvasive lineages of Neisseria meningitidis, which persist despite extensive horizontal genetic exchange, are a major cause of meningitis and septicaemia worldwide. Over the past 50 years one such lineage of meningococci, known as serogroup A, clonal complex 5 (A:cc5), has caused three successive pandemics, including epidemics in sub-Saharan Africa. Although the principal antigens that invoke effective immunity have remained unchanged, distinct A:cc5 epidemic clones have nevertheless emerged. An analysis of whole genome sequence diversity among 153 A:cc5 isolates identified eleven genetic introgression events in the emergence of the epidemic clones, which primarily involved variants of core genes encoding metabolic processes. The acquired DNA was identical to that found over many years in other, unrelated, hyperinvasive meningococci, suggesting that the epidemic clones emerged by acquisition of pre-existing metabolic gene variants, rather than ‘virulence’ associated or antigen-encoding genes. This is consistent with mathematical models which predict the association of transmission fitness with the emergence and maintenance of virulence in recombining commensal organisms.
Collapse
|
44
|
Comparative evaluation of aggressiveness traits in staphylococcal strains from severe infections versus nasopharyngeal carriage. Microb Pathog 2016; 102:45-53. [PMID: 27856272 DOI: 10.1016/j.micpath.2016.11.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 11/08/2016] [Accepted: 11/08/2016] [Indexed: 01/09/2023]
Abstract
Despite their commensal status, staphylococci can become problematic pathogens expressing multiple and redundant virulence factors. This study aimed to evaluate aggressiveness markers comparatively in staphylococcal strains isolated from severe infections versus asymptomatic carriage in order to identify clinically relevant bacterial traits that could easily be detected in clinical practice and could be suggestive for particular host-pathogen interactions such as cyto-adhesion or biofilm formation, ultimately orienting the clinical decision-making process. We have used in vitro phenotypic methods to assess adhesion to and invasion of eukaryotic cells, biofilm development, and expression of soluble virulence factors in 92 Staphylococcus spp. strains. The adhesion index, invasion capacity, biofilm formation and expression of soluble factors did not differ significantly between clinical and commensal strains. The major bacterial traits we found to be significantly more prevalent in clinical staphylococci were the aggregative adhesion pattern (P = 0.012), cluster adhesion (P = 0.001) and tetrad morphology (P = 0.018). The aggregative adhesion pattern was correlated with higher cyto-adhesion (P < 0.001), higher invasion capacity (P = 0.003) and lower Carmeli scores (P = 0.002). Three major bacterial traits, namely tetrad morphology, aggregative adhesion pattern, and resistance to methicillin (acronym: TAM), can be used to compute an aggressiveness score (SAS) predictive of the staphylococcal strain's virulence and capacity to initiate and develop a biofilm-driven chronic infectious process versus a fulminant acute infection, in a susceptible host.
Collapse
|
45
|
|