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Hurley KE, Banerjee SK, Stephens AC, Scribner MR, Cooper VS, Richardson AR. The contribution of DNA repair pathways to Staphylococcus aureus fitness and fidelity during nitric oxide stress. mBio 2023; 14:e0215623. [PMID: 37948342 PMCID: PMC10746251 DOI: 10.1128/mbio.02156-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 10/04/2023] [Indexed: 11/12/2023] Open
Abstract
Staphylococcus aureus is a major human pathogen that causes a variety of illnesses, ranging from minor skin and soft tissue infections to more severe systemic infections. Although the primary host immune response can typically clear bacterial infections, S. aureus is uniquely resistant to inflammation. For instance, our laboratory has determined that S. aureus is highly resistant to nitric oxide (NO⋅), an important component of the innate immune response that plays a role in both immunomodulatory and antibacterial processes. Additionally, NO⋅ and its derivatives can cause damage to S. aureus DNA, more specifically, deamination and/or oxidation of DNA bases; however, regulation and repair mechanisms of DNA in S. aureus are understudied. Thus, we hypothesize that several DNA repair mechanisms may account for the replication fidelity of S. aureus and may contribute to fitness in the presence of NO⋅. Here, we show the role of several DNA repair mechanisms in S. aureus. More specifically, we found that recombinational repair genes recJ, recG, and polA may play a role in the repair of NO⋅-induced replication fork collapses. We also show the role of the base excision repair pathway protein, MutY, in reducing NO⋅-mediated mutagenesis. Overall, our results suggest that NO⋅ leads to DNA damage, which subsequently induces the activity of several DNA repair pathways, contributing to the replication fidelity and fitness of S. aureus.IMPORTANCEPathogenic bacteria must evolve various mechanisms in order to evade the host immune response that they are infecting. One aspect of the primary host immune response to an infection is the production of an inflammatory effector component, nitric oxide (NO⋅). Staphylococcus aureus has uniquely evolved a diverse array of strategies to circumvent the inhibitory activity of nitric oxide. One such mechanism by which S. aureus has evolved allows the pathogen to survive and maintain its genomic integrity in this environment. For instance, here, our results suggest that S. aureus employs several DNA repair pathways to ensure replicative fitness and fidelity under NO⋅ stress. Thus, our study presents evidence of an additional strategy that allows S. aureus to evade the cytotoxic effects of host NO⋅.
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Affiliation(s)
- Kelly E. Hurley
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Srijon K. Banerjee
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Amelia C. Stephens
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Michelle R. Scribner
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Vaughn S. Cooper
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Anthony R. Richardson
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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2
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Ambrosio FJ, Scribner MR, Wright SM, Otieno JR, Doughty EL, Gorzalski A, Siao DD, Killian S, Hua C, Schneider E, Tran M, Varghese V, Libuit KG, Pandori M, Sevinsky JR, Hess D. TheiaEuk: a species-agnostic bioinformatics workflow for fungal genomic characterization. Front Public Health 2023; 11:1198213. [PMID: 37593727 PMCID: PMC10428623 DOI: 10.3389/fpubh.2023.1198213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 07/04/2023] [Indexed: 08/19/2023] Open
Abstract
Introduction The clinical incidence of antimicrobial-resistant fungal infections has dramatically increased in recent years. Certain fungal pathogens colonize various body cavities, leading to life-threatening bloodstream infections. However, the identification and characterization of fungal isolates in laboratories remain a significant diagnostic challenge in medicine and public health. Whole-genome sequencing provides an unbiased and uniform identification pipeline for fungal pathogens but most bioinformatic analysis pipelines focus on prokaryotic species. To this end, TheiaEuk_Illumina_PE_PHB (TheiaEuk) was designed to focus on genomic analysis specialized to fungal pathogens. Methods TheiaEuk was designed using containerized components and written in the workflow description language (WDL) to facilitate deployment on the cloud-based open bioinformatics platform Terra. This species-agnostic workflow enables the analysis of fungal genomes without requiring coding, thereby reducing the entry barrier for laboratory scientists. To demonstrate the usefulness of this pipeline, an ongoing outbreak of C. auris in southern Nevada was investigated. We performed whole-genome sequence analysis of 752 new C. auris isolates from this outbreak. Furthermore, TheiaEuk was utilized to observe the accumulation of mutations in the FKS1 gene over the course of the outbreak, highlighting the utility of TheiaEuk as a monitor of emerging public health threats when combined with whole-genome sequencing surveillance of fungal pathogens. Results A primary result of this work is a curated fungal database containing 5,667 unique genomes representing 245 species. TheiaEuk also incorporates taxon-specific submodules for specific species, including clade-typing for Candida auris (C. auris). In addition, for several fungal species, it performs dynamic reference genome selection and variant calling, reporting mutations found in genes currently associated with antifungal resistance (FKS1, ERG11, FUR1). Using genome assemblies from the ATCC Mycology collection, the taxonomic identification module used by TheiaEuk correctly assigned genomes to the species level in 126/135 (93.3%) instances and to the genus level in 131/135 (97%) of instances, and provided zero false calls. Application of TheiaEuk to actual specimens obtained in the course of work at a local public health laboratory resulted in 13/15 (86.7%) correct calls at the species level, with 2/15 called at the genus level. It made zero incorrect calls. TheiaEuk accurately assessed clade type of Candida auris in 297/302 (98.3%) of instances. Discussion TheiaEuk demonstrated effectiveness in identifying fungal species from whole genome sequence. It further showed accuracy in both clade-typing of C. auris and in the identification of mutations known to associate with drug resistance in that organism.
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Affiliation(s)
| | | | | | | | | | | | | | - Steve Killian
- Alameda County Public Health Laboratory, Oakland, CA, United States
| | - Chi Hua
- Public Health Laboratories, Division of Disease Control and Health Statistics, Washington State Department of Health, Shoreline, WA, United States
| | - Emily Schneider
- Public Health Laboratories, Division of Disease Control and Health Statistics, Washington State Department of Health, Shoreline, WA, United States
| | - Michael Tran
- Public Health Laboratories, Division of Disease Control and Health Statistics, Washington State Department of Health, Shoreline, WA, United States
| | - Vici Varghese
- Alameda County Public Health Laboratory, Oakland, CA, United States
| | | | - Mark Pandori
- Nevada State Public Health Laboratory, Reno, NV, United States
- Department of Pathology and Laboratory Medicine, Reno School of Medicine, University of Nevada, Reno, NV, United States
- Department of Microbiology and Immunology, Reno School of Medicine, University of Nevada, Reno, NV, United States
| | | | - David Hess
- Nevada State Public Health Laboratory, Reno, NV, United States
- Department of Pathology and Laboratory Medicine, Reno School of Medicine, University of Nevada, Reno, NV, United States
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Gorzalski A, Ambrosio FJ, Massic L, Scribner MR, Siao DD, Hua C, Dykema P, Schneider E, Njoku C, Libuit K, Sevinsky JR, Van Hooser S, Pandori M, Hess D. The use of whole-genome sequencing and development of bioinformatics to monitor overlapping outbreaks of Candida auris in southern Nevada. Front Public Health 2023; 11:1198189. [PMID: 37522005 PMCID: PMC10374848 DOI: 10.3389/fpubh.2023.1198189] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/06/2023] [Indexed: 08/01/2023] Open
Abstract
A Candida auris outbreak has been ongoing in Southern Nevada since August 2021. In this manuscript we describe the sequencing of over 200 C. auris isolates from patients at several facilities. Genetically distinct subgroups of C. auris were detected from Clade I (3 distinct lineages) and III (1 lineage). Open-source bioinformatic tools were developed and implemented to aid in the epidemiological investigation. The work herein compares three methods for C. auris whole genome analysis: Nullarbor, MycoSNP and a new pipeline TheiaEuk. We also describe a novel analysis method focused on elucidating phylogenetic linkages between isolates within an ongoing outbreak. Moreover, this study places the ongoing outbreaks in a global context utilizing existing sequences provided worldwide. Lastly, we describe how the generated results were communicated to the epidemiologists and infection control to generate public health interventions.
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Affiliation(s)
| | | | - Lauryn Massic
- Nevada State Public Health Laboratory, Reno, NV, United States
| | | | | | - Chi Hua
- Division of Disease Control and Health Statistics, Washington State Department of Health, Public Health Laboratories, Shoreline, WA, United States
| | - Phillip Dykema
- Division of Disease Control and Health Statistics, Washington State Department of Health, Public Health Laboratories, Shoreline, WA, United States
| | - Emily Schneider
- Division of Disease Control and Health Statistics, Washington State Department of Health, Public Health Laboratories, Shoreline, WA, United States
| | - Chidinma Njoku
- Nevada Department of Health and Human Services, Las Vegas, NV, United States
| | - Kevin Libuit
- Theiagen Consulting LLC, Highlands Ranch, CO, United States
| | | | | | - Mark Pandori
- Nevada State Public Health Laboratory, Reno, NV, United States
- Department of Pathology and Laboratory Medicine, University of Nevada, Reno School of Medicine, Reno, NV, United States
- Department of Microbiology and Immunology, University of Nevada, Reno School of Medicine, Reno, NV, United States
| | - David Hess
- Nevada State Public Health Laboratory, Reno, NV, United States
- Department of Pathology and Laboratory Medicine, University of Nevada, Reno School of Medicine, Reno, NV, United States
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Libuit KG, Doughty EL, Otieno JR, Ambrosio F, Kapsak CJ, Smith EA, Wright SM, Scribner MR, Petit III RA, Mendes CI, Huergo M, Legacki G, Loreth C, Park DJ, Sevinsky JR. Accelerating bioinformatics implementation in public health. Microb Genom 2023; 9:mgen001051. [PMID: 37428142 PMCID: PMC10438813 DOI: 10.1099/mgen.0.001051] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 05/24/2023] [Indexed: 07/11/2023] Open
Abstract
We have adopted an open bioinformatics ecosystem to address the challenges of bioinformatics implementation in public health laboratories (PHLs). Bioinformatics implementation for public health requires practitioners to undertake standardized bioinformatic analyses and generate reproducible, validated and auditable results. It is essential that data storage and analysis are scalable, portable and secure, and that implementation of bioinformatics fits within the operational constraints of the laboratory. We address these requirements using Terra, a web-based data analysis platform with a graphical user interface connecting users to bioinformatics analyses without the use of code. We have developed bioinformatics workflows for use with Terra that specifically meet the needs of public health practitioners. These Theiagen workflows perform genome assembly, quality control, and characterization, as well as construction of phylogeny for insights into genomic epidemiology. Additonally, these workflows use open-source containerized software and the WDL workflow language to ensure standardization and interoperability with other bioinformatics solutions, whilst being adaptable by the user. They are all open source and publicly available in Dockstore with the version-controlled code available in public GitHub repositories. They have been written to generate outputs in standardized file formats to allow for further downstream analysis and visualization with separate genomic epidemiology software. Testament to this solution meeting the requirements for bioinformatic implementation in public health, Theiagen workflows have collectively been used for over 5 million sample analyses in the last 2 years by over 90 public health laboratories in at least 40 different countries. Continued adoption of technological innovations and development of further workflows will ensure that this ecosystem continues to benefit PHLs.
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Affiliation(s)
- Kevin G. Libuit
- Theiagen Genomics, Suite 400, 1745 Shea Center Drive, Highlands Ranch, CO, 80129, USA
| | - Emma L. Doughty
- Theiagen Genomics, Suite 400, 1745 Shea Center Drive, Highlands Ranch, CO, 80129, USA
| | - James R. Otieno
- Theiagen Genomics, Suite 400, 1745 Shea Center Drive, Highlands Ranch, CO, 80129, USA
| | - Frank Ambrosio
- Theiagen Genomics, Suite 400, 1745 Shea Center Drive, Highlands Ranch, CO, 80129, USA
| | - Curtis J. Kapsak
- Theiagen Genomics, Suite 400, 1745 Shea Center Drive, Highlands Ranch, CO, 80129, USA
| | - Emily A. Smith
- Theiagen Genomics, Suite 400, 1745 Shea Center Drive, Highlands Ranch, CO, 80129, USA
| | - Sage M. Wright
- Theiagen Genomics, Suite 400, 1745 Shea Center Drive, Highlands Ranch, CO, 80129, USA
| | - Michelle R. Scribner
- Theiagen Genomics, Suite 400, 1745 Shea Center Drive, Highlands Ranch, CO, 80129, USA
| | - Robert A. Petit III
- Theiagen Genomics, Suite 400, 1745 Shea Center Drive, Highlands Ranch, CO, 80129, USA
- Wyoming Public Health Laboratory, 208 S College Dr, Cheyenne, WY 82007, USA
| | - Catarina Inês Mendes
- Theiagen Genomics, Suite 400, 1745 Shea Center Drive, Highlands Ranch, CO, 80129, USA
| | - Marcela Huergo
- Theiagen Genomics, Suite 400, 1745 Shea Center Drive, Highlands Ranch, CO, 80129, USA
| | - Gregory Legacki
- Theiagen Genomics, Suite 400, 1745 Shea Center Drive, Highlands Ranch, CO, 80129, USA
| | - Christine Loreth
- Broad Institute of Harvard and MIT, 415 Main St, Cambridge, MA 02142, USA
| | - Daniel J. Park
- Broad Institute of Harvard and MIT, 415 Main St, Cambridge, MA 02142, USA
| | - Joel R. Sevinsky
- Theiagen Genomics, Suite 400, 1745 Shea Center Drive, Highlands Ranch, CO, 80129, USA
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5
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Smith EA, Libuit KG, Kapsak CJ, Scribner MR, Wright SM, Bell J, Morales C, Crumpler M, Messenger S, Hacker JK, Ledin K, Glaser C, Jacobson K, Sevinsky JR, Wadford DA. Pathogen genomics in public health laboratories: successes, challenges, and lessons learned from California's SARS-CoV-2 Whole-Genome Sequencing Initiative, California COVIDNet. Microb Genom 2023; 9. [PMID: 37267020 DOI: 10.1099/mgen.0.001027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023] Open
Abstract
The capacity for pathogen genomics in public health expanded rapidly during the coronavirus disease 2019 (COVID-19) pandemic, but many public health laboratories did not have the infrastructure in place to handle the vast amount of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequence data generated. The California Department of Public Health, in partnership with Theiagen Genomics, was an early adopter of cloud-based resources for bioinformatics and genomic epidemiology, resulting in the creation of a SARS-CoV-2 genomic surveillance system that combined the efforts of more than 40 sequencing laboratories across government, academia and industry to form California COVIDNet, California's SARS-CoV-2 Whole-Genome Sequencing Initiative. Open-source bioinformatics workflows, ongoing training sessions for the public health workforce, and automated data transfer to visualization tools all contributed to the success of California COVIDNet. While challenges remain for public health genomic surveillance worldwide, California COVIDNet serves as a framework for a scaled and successful bioinformatics infrastructure that has expanded beyond SARS-CoV-2 to other pathogens of public health importance.
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Affiliation(s)
| | | | | | | | | | - John Bell
- California Department of Public Health, Richmond, California, USA
| | | | - Megan Crumpler
- Orange County Public Health Laboratory, Santa Ana, California, USA
| | - Sharon Messenger
- California Department of Public Health, Richmond, California, USA
| | - Jill K Hacker
- California Department of Public Health, Richmond, California, USA
| | - Katya Ledin
- California Department of Public Health, Richmond, California, USA
| | - Carol Glaser
- California Department of Public Health, Richmond, California, USA
| | | | | | - Debra A Wadford
- California Department of Public Health, Richmond, California, USA
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6
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Konikkat S, Scribner MR, Eutsey R, Hiller NL, Cooper VS, McManus J. Quantitative mapping of mRNA 3' ends in Pseudomonas aeruginosa reveals a pervasive role for premature 3' end formation in response to azithromycin. PLoS Genet 2021; 17:e1009634. [PMID: 34252072 PMCID: PMC8297930 DOI: 10.1371/journal.pgen.1009634] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 07/22/2021] [Accepted: 06/01/2021] [Indexed: 01/06/2023] Open
Abstract
Pseudomonas aeruginosa produces serious chronic infections in hospitalized patients and immunocompromised individuals, including patients with cystic fibrosis. The molecular mechanisms by which P. aeruginosa responds to antibiotics and other stresses to promote persistent infections may provide new avenues for therapeutic intervention. Azithromycin (AZM), an antibiotic frequently used in cystic fibrosis treatment, is thought to improve clinical outcomes through a number of mechanisms including impaired biofilm growth and quorum sensing (QS). The mechanisms underlying the transcriptional response to AZM remain unclear. Here, we interrogated the P. aeruginosa transcriptional response to AZM using a fast, cost-effective genome-wide approach to quantitate RNA 3’ ends (3pMap). We also identified hundreds of P. aeruginosa genes with high incidence of premature 3’ end formation indicative of riboregulation in their transcript leaders using 3pMap. AZM treatment of planktonic and biofilm cultures alters the expression of hundreds of genes, including those involved in QS, biofilm formation, and virulence. Strikingly, most genes downregulated by AZM in biofilms had increased levels of intragenic 3’ ends indicating premature transcription termination, transcriptional pausing, or accumulation of stable intermediates resulting from the action of nucleases. Reciprocally, AZM reduced premature intragenic 3’ end termini in many upregulated genes. Most notably, reduced termination accompanied robust induction of obgE, a GTPase involved in persister formation in P. aeruginosa. Our results support a model in which AZM-induced changes in 3’ end formation alter the expression of central regulators which in turn impairs the expression of QS, biofilm formation and stress response genes, while upregulating genes associated with persistence. Pseudomonas aeruginosa is a common source of hospital-acquired infections and causes prolonged illness in patients with cystic fibrosis. P. aeruginosa infections are often treated with the macrolide antibiotic azithromycin, which changes the expression of many genes involved in infection. By examining such expression changes at nucleotide resolution, we found azithromycin treatment alters the locations of mRNA 3’ ends suggesting most downregulated genes are subject to premature 3’ end formation. We further identified candidate RNA regulatory elements that P. aeruginosa may use to control gene expression. Our work provides new insights in P. aeruginosa gene regulation and its response to antibiotics.
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Affiliation(s)
- Salini Konikkat
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Michelle R. Scribner
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Rory Eutsey
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - N. Luisa Hiller
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Vaughn S. Cooper
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Joel McManus
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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7
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Santos-Lopez A, Marshall CW, Scribner MR, Snyder DJ, Cooper VS. Evolutionary pathways to antibiotic resistance are dependent upon environmental structure and bacterial lifestyle. eLife 2019; 8:47612. [PMID: 31516122 PMCID: PMC6814407 DOI: 10.7554/elife.47612] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 09/13/2019] [Indexed: 12/11/2022] Open
Abstract
Bacterial populations vary in their stress tolerance and population structure depending upon whether growth occurs in well-mixed or structured environments. We hypothesized that evolution in biofilms would generate greater genetic diversity than well-mixed environments and lead to different pathways of antibiotic resistance. We used experimental evolution and whole genome sequencing to test how the biofilm lifestyle influenced the rate, genetic mechanisms, and pleiotropic effects of resistance to ciprofloxacin in Acinetobacter baumannii populations. Both evolutionary dynamics and the identities of mutations differed between lifestyle. Planktonic populations experienced selective sweeps of mutations including the primary topoisomerase drug targets, whereas biofilm-adapted populations acquired mutations in regulators of efflux pumps. An overall trade-off between fitness and resistance level emerged, wherein biofilm-adapted clones were less resistant than planktonic but more fit in the absence of drug. However, biofilm populations developed collateral sensitivity to cephalosporins, demonstrating the clinical relevance of lifestyle on the evolution of resistance. A bacterium known as Acinetobacter baumannii causes serious lung infections in people with weakened immune systems. These illnesses are becoming more common largely because A. baumannii is increasingly developing resistance to antibiotics. Inside the airways, individual A. baumannii cells can stick together and coat themselves in a slimy substance to form a structure called biofilm, which physically protects bacteria from antibiotics. This may be one of the reasons why it is often harder to treat bacterial infections associated with biofilms. Another possibility is that bacteria may evolve differently in biofilms compared with cells living independently. For example, A. baumannii may colonize several regions of the lungs during an infection, leading to distinct groups of bacteria that experience different conditions and evolve separately. Each population may therefore respond differently to an antibiotic. In contrast, bacteria living independently in a well-mixed population – such as in the bloodstream of their host – would be more likely to all evolve in the same way. Santos-Lopez, Marshall et al. tested this theory by exposing populations of A. baumannii that lived either independently or in biofilms to increasing levels of an antibiotic called ciprofloxacin. The genetic information of these cells was examined as the populations were evolving, and the bacteria were also put in contact with other types of antibiotics. The analyses revealed that bacteria in well-mixed populations shared the same limited number of mutations: these gave the bacteria high levels of resistance to the antibiotic’s primary target, an enzyme involved in DNA processes. The bacteria had also become resistant to other classes of antibiotics. In contrast, the bacteria in biofilm populations evolved to be more genetically diverse, exhibiting different types of mutations that helped the cells to pump out the drug. These bacteria were less resistant to ciprofloxacin and more sensitive to other types of antibiotics. Further experiments looked into the fitness of the bacteria – their ability to survive, reproduce and compete with each other. High levels of antibiotic resistance came with lower fitness: biofilm bacteria had evolved to become being fitter than those from well-mixed population. Even in the absence of drugs, these populations were in fact fitter than the original cells. Overall, understanding how the lifestyles of bacteria affect the way they respond to drugs may help researchers to develop new approaches that limit the spread of antibiotic resistance and improve treatment.
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Affiliation(s)
- Alfonso Santos-Lopez
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, United States.,Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, United States
| | - Christopher W Marshall
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, United States.,Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, United States
| | - Michelle R Scribner
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, United States.,Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, United States
| | - Daniel J Snyder
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, United States.,Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, United States.,Microbial Genome Sequencing Center, University of Pittsburgh, Pittsburgh, United States
| | - Vaughn S Cooper
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, United States.,Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, United States.,Microbial Genome Sequencing Center, University of Pittsburgh, Pittsburgh, United States
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8
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Woodham EF, Paul NR, Tyrrell B, Spence HJ, Swaminathan K, Scribner MR, Giampazolias E, Hedley A, Clark W, Kage F, Marston DJ, Hahn KM, Tait SWG, Larue L, Brakebusch CH, Insall RH, Machesky LM. Coordination by Cdc42 of Actin, Contractility, and Adhesion for Melanoblast Movement in Mouse Skin. Curr Biol 2017; 27:624-637. [PMID: 28238662 PMCID: PMC5344686 DOI: 10.1016/j.cub.2017.01.033] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Revised: 12/12/2016] [Accepted: 01/19/2017] [Indexed: 12/20/2022]
Abstract
The individual molecular pathways downstream of Cdc42, Rac, and Rho GTPases are well documented, but we know surprisingly little about how these pathways are coordinated when cells move in a complex environment in vivo. In the developing embryo, melanoblasts originating from the neural crest must traverse the dermis to reach the epidermis of the skin and hair follicles. We previously established that Rac1 signals via Scar/WAVE and Arp2/3 to effect pseudopod extension and migration of melanoblasts in skin. Here we show that RhoA is redundant in the melanocyte lineage but that Cdc42 coordinates multiple motility systems independent of Rac1. Similar to Rac1 knockouts, Cdc42 null mice displayed a severe loss of pigmentation, and melanoblasts showed cell-cycle progression, migration, and cytokinesis defects. However, unlike Rac1 knockouts, Cdc42 null melanoblasts were elongated and displayed large, bulky pseudopods with dynamic actin bursts. Despite assuming an elongated shape usually associated with fast mesenchymal motility, Cdc42 knockout melanoblasts migrated slowly and inefficiently in the epidermis, with nearly static pseudopods. Although much of the basic actin machinery was intact, Cdc42 null cells lacked the ability to polarize their Golgi and coordinate motility systems for efficient movement. Loss of Cdc42 de-coupled three main systems: actin assembly via the formin FMNL2 and Arp2/3, active myosin-II localization, and integrin-based adhesion dynamics.
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Affiliation(s)
- Emma F Woodham
- CRUK Beatson Institute, University of Glasgow, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Nikki R Paul
- CRUK Beatson Institute, University of Glasgow, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Benjamin Tyrrell
- CRUK Beatson Institute, University of Glasgow, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Heather J Spence
- CRUK Beatson Institute, University of Glasgow, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Karthic Swaminathan
- CRUK Beatson Institute, University of Glasgow, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Michelle R Scribner
- CRUK Beatson Institute, University of Glasgow, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Evangelos Giampazolias
- CRUK Beatson Institute, University of Glasgow, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Ann Hedley
- CRUK Beatson Institute, University of Glasgow, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - William Clark
- CRUK Beatson Institute, University of Glasgow, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Frieda Kage
- Division of Molecular Cell Biology, Zoological Institute, Technische Universität Braunschweig, Spielmannstrasse 7, 38106 Braunschweig, Germany; Molecular Cell Biology Group, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | - Daniel J Marston
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27514, USA
| | - Klaus M Hahn
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27514, USA
| | - Stephen W G Tait
- CRUK Beatson Institute, University of Glasgow, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Lionel Larue
- Institute Curie, CNRS UMR3347, INSERM U1021, Bat 110, Centre Universitaire, 91405 Orsay Cedex, France
| | - Cord H Brakebusch
- Biotech Research Center, University of Copenhagen, Ole Maaløes Vej 5, Copenhagen 2200, Denmark
| | - Robert H Insall
- CRUK Beatson Institute, University of Glasgow, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Laura M Machesky
- CRUK Beatson Institute, University of Glasgow, Switchback Road, Bearsden, Glasgow G61 1BD, UK.
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