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De Francesco MA, Bertelli A, Corbellini S, Scaltriti E, Risso F, Allegri R, Tiecco G, Castelli F, Caruso A. Emergence of Pandemic Clonal Lineage Sequence Types 131 and 69 of Extraintestinal Escherichia coli as a Cause of Meningitis: Is It Time To Revise Molecular Assays? Microbiol Spectr 2023; 11:e0327422. [PMID: 36786647 PMCID: PMC10100906 DOI: 10.1128/spectrum.03274-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 01/24/2023] [Indexed: 02/15/2023] Open
Abstract
Two Escherichia coli strains, respectively responsible for neonatal and adult meningitis, were isolated and their phenotypic antibiotic susceptibility and genomic features characterized by whole-genome sequencing (WGS). Multiplex real-time PCR targeting the principal microorganisms involved in meningitis etiology failed to identify either isolate. Afterwards, matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry was used to identify the isolates as E. coli strains. Genomic analysis showed that they belonged to sequence types 131 and 69 (ST131 and ST69). Neither of the isolates harbored the K1 capsular antigen or belonged to other capsular serotypes, but they shared different virulence factors, including ibe genes, responsible for invasion of brain endothelial cells. IMPORTANCE The extraintestinal pathogenic Escherichia coli group is characterized by the presence of uropathogenic E. coli (UPEC), sepsis-associated E. coli (SEPEC), and neonatal meningitis E. coli (NMEC). All of these members exhibit many virulence factors, such as lipopolysaccharides, toxins, iron acquisition factors, invasins, fimbriae, and capsules. Urinary infections are the most common infections caused by this group, followed by globally increasing numbers of both community- and nosocomially acquired bloodstream infections, associated with considerable patient morbidity and mortality. Some lineages tend to become dominant; in addition to enhanced fitness, this epidemiological success stems from increased virulence, antibiotic resistance, gut colonization, and greater host-to-host transmission. Our results underline the importance of continuous surveillance of these new emerging lineages and the need to develop new meningitis molecular assay panels able to identify them.
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Affiliation(s)
- Maria Antonia De Francesco
- Institute of Microbiology, Department of Molecular and Translational Medicine, University of Brescia, ASST Spedali Civili, Brescia, Italy
| | - Anna Bertelli
- Institute of Microbiology, Department of Molecular and Translational Medicine, University of Brescia, ASST Spedali Civili, Brescia, Italy
| | - Silvia Corbellini
- Institute of Microbiology, Department of Molecular and Translational Medicine, University of Brescia, ASST Spedali Civili, Brescia, Italy
| | - Erika Scaltriti
- Institute of Microbiology, Department of Molecular and Translational Medicine, University of Brescia, ASST Spedali Civili, Brescia, Italy
- Risk Analysis and Genomic Epidemiology Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia Romagna, Parma, Italy
| | - Francesco Risso
- Neonatalogy and Neonatal Intensive Care Unit, ASST Spedali Civili, Brescia, Italy
| | - Roberto Allegri
- Division of Infectious and Tropical Diseases, ASST Spedali Civili, Brescia, Italy
| | - Giorgio Tiecco
- Division of Infectious and Tropical Diseases, ASST Spedali Civili, Brescia, Italy
- Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Francesco Castelli
- Division of Infectious and Tropical Diseases, ASST Spedali Civili, Brescia, Italy
- Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Arnaldo Caruso
- Institute of Microbiology, Department of Molecular and Translational Medicine, University of Brescia, ASST Spedali Civili, Brescia, Italy
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Cytolysin A (ClyA): A Bacterial Virulence Factor with Potential Applications in Nanopore Technology, Vaccine Development, and Tumor Therapy. Toxins (Basel) 2022; 14:toxins14020078. [PMID: 35202106 PMCID: PMC8880466 DOI: 10.3390/toxins14020078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/14/2022] [Accepted: 01/18/2022] [Indexed: 12/26/2022] Open
Abstract
Cytolysin A (ClyA) is a pore-forming toxin that is produced by some bacteria from the Enterobacteriaceae family. This review provides an overview of the current state of knowledge regarding ClyA, including the prevalence of the encoding gene and its transcriptional regulation, the secretion pathway used by the protein, and the mechanism of protein assembly, and highlights potential applications of ClyA in biotechnology. ClyA expression is regulated at the transcriptional level, primarily in response to environmental stressors, and ClyA can exist stably both as a soluble monomer and as an oligomeric membrane complex. At high concentrations, ClyA induces cytolysis, whereas at low concentrations ClyA can affect intracellular signaling. ClyA is secreted in outer membrane vesicles (OMVs), which has important implications for biotechnology applications. For example, the native pore-forming ability of ClyA suggests that it could be used as a component of nanopore-based technologies, such as sequencing platforms. ClyA has also been exploited in vaccine development owing to its ability to present antigens on the OMV surface and provoke a robust immune response. In addition, ClyA alone or OMVs carrying ClyA fusion proteins have been investigated for their potential use as anti-tumor agents.
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Zlatkov N, Uhlin BE. Absence of Global Stress Regulation in Escherichia coli Promotes Pathoadaptation and Novel c-di-GMP-dependent Metabolic Capability. Sci Rep 2019; 9:2600. [PMID: 30796316 PMCID: PMC6385356 DOI: 10.1038/s41598-019-39580-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 01/25/2019] [Indexed: 01/17/2023] Open
Abstract
Pathoadaptive mutations linked to c-di-GMP signalling were investigated in neonatal meningitis-causing Escherichia coli (NMEC). The results indicated that NMEC strains deficient in RpoS (the global stress regulator) maintained remarkably low levels of c-di-GMP, a major bacterial sessility-motility switch. Deletion of ycgG2, shown here to encode a YcgG allozyme with c-di-GMP phosphodiesterase activity, and the restoration of RpoS led to a decrease in S-fimbriae, robustly produced in artificial urine, hinting that the urinary tract could serve as a habitat for NMEC. We showed that NMEC were skilled in aerobic citrate utilization in the presence of glucose, a property that normally does not exist in E. coli. Our data suggest that this metabolic novelty is a property of extraintestinal pathogenic E. coli since we reconstituted this ability in E. coli UTI89 (a cystitis isolate) via deactivation rpoS; additionally, a set of pyelonephritis E. coli isolates were shown here to aerobically use citrate in the presence of glucose. We found that the main reason for this metabolic capability is RpoS inactivation leading to the production of the citrate transporter CitT, exploited by NMEC for ferric citrate uptake dependent on YcgG2 (an allozyme with c-di-GMP phosphodiesterase activity).
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Affiliation(s)
- Nikola Zlatkov
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Department of Molecular Biology, Umeå University, Umea, Sweden
| | - Bernt Eric Uhlin
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Department of Molecular Biology, Umeå University, Umea, Sweden.
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de Benito A, Ibáñez C, Moncho W, Martínez D, Vettorazzi A, de Cerain AL. Database on the taxonomical characterisation and potential toxigenic capacities of microorganisms used for the industrial production of food enzymes and feed additives, which do not have a recommendation for Qualified Presumption of Safety. EFSA SUPPORTING PUBLICATIONS 2017. [PMCID: PMC7163622 DOI: 10.2903/sp.efsa.2017.en-1274] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Bacterial pathogen gene regulation: a DNA-structure-centred view of a protein-dominated domain. Clin Sci (Lond) 2017; 130:1165-77. [PMID: 27252403 DOI: 10.1042/cs20160024] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 04/15/2016] [Indexed: 02/03/2023]
Abstract
The mechanisms used by bacterial pathogens to regulate the expression of their genes, especially their virulence genes, have been the subject of intense investigation for several decades. Whole genome sequencing projects, together with more targeted studies, have identified hundreds of DNA-binding proteins that contribute to the patterns of gene expression observed during infection as well as providing important insights into the nature of the gene products whose expression is being controlled by these proteins. Themes that have emerged include the importance of horizontal gene transfer to the evolution of pathogens, the need to impose regulatory discipline upon these imported genes and the important roles played by factors normally associated with the organization of genome architecture as regulatory principles in the control of virulence gene expression. Among these architectural elements is the structure of DNA itself, its variable nature at a topological rather than just at a base-sequence level and its ability to play an active (as well as a passive) part in the gene regulation process.
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