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De Anda-Mora KL, Tavares-Carreón F, Alvarez C, Barahona S, Becerril-García MA, Treviño-Rangel RJ, García-Contreras R, Andrade A. Increased Proteolytic Activity of Serratia marcescens Clinical Isolate HU1848 Is Associated with Higher eepR Expression. Pol J Microbiol 2024; 73:11-20. [PMID: 38437469 PMCID: PMC10911700 DOI: 10.33073/pjm-2024-002] [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: 09/22/2023] [Accepted: 12/14/2023] [Indexed: 03/06/2024] Open
Abstract
Serratia marcescens is a global opportunistic pathogen. In vitro cytotoxicity of this bacterium is mainly related to metalloprotease serralysin (PrtS) activity. Proteolytic capability varies among the different isolates. Here, we characterized protease production and transcriptional regulators at 37°C of two S. marcescens isolates from bronchial expectorations, HU1848 and SmUNAM836. As a reference strain the insect pathogen S. marcescens Db10 was included. Zymography of supernatant cultures revealed a single (SmUNAM836) or double proteolytic zones (HU1848 and Db10). Mass spectrometry confirmed the identity of PrtS and the serralysin-like protease SlpB from supernatant samples. Elevated proteolytic activity and prtS expression were evidenced in the HU1848 strain through azocasein degradation and qRT-PCR, respectively. Evaluation of transcriptional regulators revealed higher eepR expression in HU1848, whereas cpxR and hexS transcriptional levels were similar between studied strains. Higher eepR expression in HU1848 was further confirmed through an in vivo transcriptional assay. Moreover, two putative CpxR binding motifs were identified within the eepR regulatory region. EMSA validated the interaction of CpxR with both motifs. The evaluation of eepR transcription in a cpxR deletion strain indicated that CpxR negatively regulates eepR. Sequence conservation suggests that regulation of eepR by CpxR is common along S. marcescens species. Overall, our data incorporates CpxR to the complex regulatory mechanisms governing eepR expression and associates the increased proteolytic activity of the HU1848 strain with higher eepR transcription. Based on the global impact of EepR in secondary metabolites production, our work contributes to understanding virulence factors variances across S. marcescens isolates.
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Affiliation(s)
- Karla L. De Anda-Mora
- Departamento de Microbiología, Facultad de Medicina, Universidad Autónoma de Nuevo León, Monterrey, Mexico
| | - Faviola Tavares-Carreón
- Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Mexico
| | - Carlos Alvarez
- Departamento de Microbiología, Facultad de Medicina, Universidad Autónoma de Nuevo León, Monterrey, Mexico
| | - Samantha Barahona
- Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Mexico
| | - Miguel A. Becerril-García
- Departamento de Microbiología, Facultad de Medicina, Universidad Autónoma de Nuevo León, Monterrey, Mexico
| | - Rogelio J. Treviño-Rangel
- Departamento de Microbiología, Facultad de Medicina, Universidad Autónoma de Nuevo León, Monterrey, Mexico
| | - Rodolfo García-Contreras
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Angel Andrade
- Departamento de Microbiología, Facultad de Medicina, Universidad Autónoma de Nuevo León, Monterrey, Mexico
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Nazeih SI, Ali MAM, Halim ASA, Al-Lawati H, Abbas HA, Al-Zharani M, Boufahja F, Alghamdi MA, Hegazy WAH, Seleem NM. Relocating Glyceryl Trinitrate as an Anti-Virulence Agent against Pseudomonas aeruginosa and Serratia marcescens: Insights from Molecular and In Vivo Investigations. Microorganisms 2023; 11:2420. [PMID: 37894078 PMCID: PMC10609227 DOI: 10.3390/microorganisms11102420] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 09/23/2023] [Accepted: 09/24/2023] [Indexed: 10/29/2023] Open
Abstract
The problem of antibiotic resistance is a global critical public health concern. In light of the threat of returning to the pre-antibiotic era, new alternative approaches are required such as quorum-sensing (QS) disruption and virulence inhibition, both of which apply no discernible selective pressure on bacteria, therefore mitigating the potential for the development of resistant strains. Bearing in mind the significant role of QS in orchestrating bacterial virulence, disrupting QS becomes essential for effectively diminishing bacterial virulence. This study aimed to assess the potential use of sub-inhibitory concentration (0.25 mg/mL) of glyceryl trinitrate (GTN) to inhibit virulence in Serratia marcescens and Pseudomonas aeruginosa. GTN could decrease the expression of virulence genes in both tested bacteria in a significant manner. Histopathological study revealed the ability of GTN to alleviate the congestion in hepatic and renal tissues of infected mice and to reduce bacterial and leukocyte infiltration. This study recommends the use of topical GTN to treat topical infection caused by P. aeruginosa and S. marcescens in combination with antibiotics.
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Affiliation(s)
- Shaimaa I. Nazeih
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt; (S.I.N.); (H.A.A.); (N.M.S.)
| | - Mohamed A. M. Ali
- Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11623, Saudi Arabia; (M.A.M.A.); (F.B.)
- Department of Biochemistry, Faculty of Science, Ain Shams University, Abbassia, Cairo 11566, Egypt;
| | - Alyaa S. Abdel Halim
- Department of Biochemistry, Faculty of Science, Ain Shams University, Abbassia, Cairo 11566, Egypt;
| | - Hanan Al-Lawati
- Pharmacy Program, Department of Pharmaceutics, Oman College of Health Sciences, Muscat 113, Oman;
| | - Hisham A. Abbas
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt; (S.I.N.); (H.A.A.); (N.M.S.)
| | - Mohammed Al-Zharani
- Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11623, Saudi Arabia; (M.A.M.A.); (F.B.)
| | - Fehmi Boufahja
- Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11623, Saudi Arabia; (M.A.M.A.); (F.B.)
| | - Mashael A. Alghamdi
- Department of Chemistry, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11623, Saudi Arabia;
| | - Wael A. H. Hegazy
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt; (S.I.N.); (H.A.A.); (N.M.S.)
- Pharmacy Program, Department of Pharmaceutical Sciences, Oman College of Health Sciences, Muscat 113, Oman
| | - Noura M. Seleem
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt; (S.I.N.); (H.A.A.); (N.M.S.)
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Khayat MT, Elbaramawi SS, Nazeih SI, Safo MK, Khafagy ES, Ali MAM, Abbas HA, Hegazy WAH, Seleem NM. Diminishing the Pathogenesis of the Food-Borne Pathogen Serratia marcescens by Low Doses of Sodium Citrate. BIOLOGY 2023; 12:biology12040504. [PMID: 37106705 PMCID: PMC10135860 DOI: 10.3390/biology12040504] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 03/21/2023] [Accepted: 03/25/2023] [Indexed: 03/29/2023]
Abstract
Protecting food from bacterial contamination is crucial for ensuring its safety and avoiding foodborne illness. Serratia marcescens is one of the food bacterial contaminants that can form biofilms and pigments that spoil the food product and could cause infections and illness to the consumer. Food preservation is essential to diminish such bacterial contaminants or at least reduce their pathogenesis; however, it should not affect food odor, taste, and consistency and must be safe. Sodium citrate is a well-known safe food additive and the current study aims to evaluate its anti-virulence and anti-biofilm activity at low concentrations against S. marcescens. The anti-virulence and antibiofilm activities of sodium citrate were evaluated phenotypically and genotypically. The results showed the significant effect of sodium citrate on decreasing the biofilm formation and other virulence factors, such as motility and the production of prodigiosin, protease, and hemolysins. This could be owed to its downregulating effect on the virulence-encoding genes. An in vivo investigation was conducted on mice and the histopathological examination of isolated tissues from the liver and kidney of mice confirmed the anti-virulence activity of sodium citrate. In addition, an in silico docking study was conducted to evaluate the sodium citrate binding ability to S. marcescens quorum sensing (QS) receptors that regulates its virulence. Sodium citrate showed a marked virtual ability to compete on QS proteins, which could explain sodium citrate’s anti-virulence effect. In conclusion, sodium citrate is a safe food additive and can be used at low concentrations to prevent contamination and biofilm formation by S. marcescens and other bacteria.
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Affiliation(s)
- Maan T. Khayat
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Correspondence: (M.T.K.); (W.A.H.H.)
| | - Samar S. Elbaramawi
- Medicinal Chemistry Department, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt
| | - Shaimaa I. Nazeih
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt
| | - Martin K. Safo
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23219, USA
| | - El-Sayed Khafagy
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-kharj 11942, Saudi Arabia
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Suez Canal University, Ismailia 41552, Egypt
| | - Mohamed A. M. Ali
- Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University, Riyadh 11432, Saudi Arabia
- Department of Biochemistry, Faculty of Science, Ain Shams University, Cairo 11566, Egypt
| | - Hisham A. Abbas
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt
| | - Wael A. H. Hegazy
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt
- Pharmacy Program, Department of Pharmaceutical Sciences, Oman College of Health Sciences, Muscat 113, Oman
- Correspondence: (M.T.K.); (W.A.H.H.)
| | - Noura M. Seleem
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt
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Stella NA, Romanowski EG, Brothers KM, Calvario RC, Shanks RMQ. IgaA Protein, GumB, Has a Global Impact on the Transcriptome and Surface Proteome of Serratia marcescens. Infect Immun 2022; 90:e0039922. [PMID: 36317876 PMCID: PMC9671016 DOI: 10.1128/iai.00399-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 09/30/2022] [Indexed: 11/07/2022] Open
Abstract
Bacterial stress response signaling systems, like the Rcs system are triggered by membrane and cell wall damaging compounds, including antibiotics and immune system factors. These regulatory systems help bacteria survive envelope stress by altering the transcriptome resulting in protective phenotypic changes that may also influence the virulence of the bacterium. This study investigated the role of the Rcs stress response system using a clinical keratitis isolate of Serratia marcescens with a mutation in the gumB gene. GumB, an IgaA ortholog, inhibits activation of the Rcs system, such that mutants have overactive Rcs signaling. Transcriptomic analysis indicated that approximately 15% of all S. marcescens genes were significantly altered with 2-fold or greater changes in expression in the ΔgumB mutant compared to the wild type, indicating a global transcriptional regulatory role for GumB. We further investigated the phenotypic consequences of two classes of genes with altered expression in the ΔgumB mutant expected to contribute to infections: serralysin metalloproteases PrtS, SlpB, and SlpE, and type I pili coded by fimABCD. Secreted fractions from the ΔgumB mutant had reduced cytotoxicity to a corneal cell line, and could be complemented by induced expression of prtS, but not cytolysin shlBA, phospholipase phlAB, or flagellar master regulator flhDC operons. Proteomic analysis, qRT-PCR, and type I pili-dependent yeast agglutination indicated an inhibitory role for the Rcs system in adhesin production. Together these data demonstrate GumB has a global impact on S. marcescens gene expression that had measurable effects on bacterial cytotoxicity and surface adhesin production.
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Affiliation(s)
- Nicholas A. Stella
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh Pennsylvania, USA
| | - Eric G. Romanowski
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh Pennsylvania, USA
| | - Kimberly M. Brothers
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh Pennsylvania, USA
| | - Rachel C. Calvario
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh Pennsylvania, USA
| | - Robert M. Q. Shanks
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh Pennsylvania, USA
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Terazosin Interferes with Quorum Sensing and Type Three Secretion System and Diminishes the Bacterial Espionage to Mitigate the Salmonella Typhimurium Pathogenesis. Antibiotics (Basel) 2022; 11:antibiotics11040465. [PMID: 35453216 PMCID: PMC9025009 DOI: 10.3390/antibiotics11040465] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 03/20/2022] [Accepted: 03/27/2022] [Indexed: 02/05/2023] Open
Abstract
Salmonella enterica is an invasive intracellular pathogen and hires diverse systems to manipulate its survival in the host cells. Salmonella could eavesdrop on the host cells, sensing and responding to the produced adrenergic hormones and other neurotransmitters, which results in the augmentation of its virulence and establishes its accommodation in host cells. The current study aims to assess the anti-virulence effect of α-adrenergic antagonist terazosin on S. Typhimurium. Our findings show that terazosin significantly reduced S. Typhimurium adhesion and biofilm formation. Furthermore, terazosin significantly decreased invasion and intracellular replication of S. Typhimurium. Interestingly, in vivo, terazosin protected the mice from S. Typhimurium pathogenesis. To understand the terazosin anti-virulence activity, its effect on quorum sensing (QS), bacterial espionage, and type three secretion system (T3SS) was studied. Strikingly, terazosin competed on the membranal sensors that sense adrenergic hormones and down-regulated their encoding genes, which indicates the ability of terazosin to diminish the bacterial eavesdropping on the host cells. Moreover, terazosin significantly reduced the Chromobacterium violaceum QS-controlled pigment production and interfered with the QS receptor Lux-homolog Salmonella SdiA, which indicates the possible terazosin-mediated anti-QS activity. Furthermore, terazosin down-regulated the expression of T3SS encoding genes. In conclusion, terazosin may mitigate S. Typhimurium virulence owing to its hindering QS and down-regulating T3SS encoding genes besides its inhibition of bacterial espionage.
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6
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Computational and Biological Evaluation of β-Adrenoreceptor Blockers as Promising Bacterial Anti-Virulence Agents. Pharmaceuticals (Basel) 2022; 15:ph15020110. [PMID: 35215223 PMCID: PMC8877484 DOI: 10.3390/ph15020110] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/10/2022] [Accepted: 01/12/2022] [Indexed: 02/04/2023] Open
Abstract
Bacterial resistance to antibiotics is an increasing public health threat as it has the potential to affect people at any stage of life, as well as veterinary. Various approaches have been proposed to counteract the bacterial resistance development. Tackling bacterial virulence is one of the most promising approaches that confer several merits. The bacterial virulence is mainly regulated by a communication system known as quorum sensing (QS) system. Meanwhile, bacteria can sense the adrenergic hormones and eavesdrops on the host cells to establish their infection, adrenergic hormones were shown to enhance the bacterial virulence. In this study, β-adrenoreceptor blockers were proposed not only to stop bacterial espionage on our cells but also as inhibitors to the bacterial QS systems. In this context, a detailed in silico study has been conducted to evaluate the affinities of twenty-two β-blockers to compete on different structural QS receptors. Among the best docked and thermodynamically stable β-blockers; atenolol, esmolol, and metoprolol were subjected to further in vitro and in vivo investigation to evaluate their anti-QS activities against Chromobacterium violaceum, Pseudomonas aeruginosa and Salmonella typhimurium. The three tested β-blockers decreased the production of QS-controlled C. violaceum, and the formation of biofilm by P. aeruginosa and S. typhimurium. Additionally, the tested β-blockers down-regulated the P. aeruginosa QS-encoding genes and S. typhimurium sensor kinase encoding genes. Furthermore, metoprolol protected mice against P. aeruginosa and S. typhimurium. Conclusively, these investigated β-blockers are promising anti-virulence agents antagonizing adrenergic hormones induced virulence, preventing bacterial espionage, and blocking bacterial QS systems.
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Pan X, Tang M, You J, Osire T, Sun C, Fu W, Yi G, Yang T, Yang ST, Rao Z. PsrA is a novel regulator contributes to antibiotic synthesis, bacterial virulence, cell motility and extracellular polysaccharides production in Serratia marcescens. Nucleic Acids Res 2021; 50:127-148. [PMID: 34893884 PMCID: PMC8754645 DOI: 10.1093/nar/gkab1186] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 11/13/2021] [Accepted: 12/03/2021] [Indexed: 12/23/2022] Open
Abstract
Serratia marcescens is a Gram-negative bacterium of the Enterobacteriaceae family that can produce numbers of biologically active secondary metabolites. However, our understanding of the regulatory mechanisms behind secondary metabolites biosynthesis in S. marcescens remains limited. In this study, we identified an uncharacterized LysR family transcriptional regulator, encoding gene BVG90_12635, here we named psrA, that positively controlled prodigiosin synthesis in S. marcescens. This phenotype corresponded to PsrA positive control of transcriptional of the prodigiosin-associated pig operon by directly binding to a regulatory binding site (RBS) and an activating binding site (ABS) in the promoter region of the pig operon. We demonstrated that L-proline is an effector for the PsrA, which enhances the binding affinity of PsrA to its target promoters. Using transcriptomics and further experiments, we show that PsrA indirectly regulates pleiotropic phenotypes, including serrawettin W1 biosynthesis, extracellular polysaccharide production, biofilm formation, swarming motility and T6SS-mediated antibacterial activity in S. marcescens. Collectively, this study proposes that PsrA is a novel regulator that contributes to antibiotic synthesis, bacterial virulence, cell motility and extracellular polysaccharides production in S. marcescens and provides important clues for future studies exploring the function of the PsrA and PsrA-like proteins which are widely present in many other bacteria.
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Affiliation(s)
- Xuewei Pan
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Mi Tang
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Jiajia You
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Tolbert Osire
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Changhao Sun
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Weilai Fu
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,Fujian Dabeinong Aquatic Sci. & Tech. Co., Ltd., Zhangzhou 363500, China
| | - Ganfeng Yi
- Fujian Dabeinong Aquatic Sci. & Tech. Co., Ltd., Zhangzhou 363500, China
| | - Taowei Yang
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Shang-Tian Yang
- Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH 43210, USA
| | - Zhiming Rao
- Key Laboratory of Industrial Biotechnology of the Ministry of Education, Laboratory of Applied Microorganisms and Metabolic Engineering, School of Biotechnology, Jiangnan University, Wuxi 214122, China
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The Rcs Stress Response System Regulator GumB Modulates Serratia marcescens-Induced Inflammation and Bacterial Proliferation in a Rabbit Keratitis Model and Cytotoxicity In Vitro. Infect Immun 2021; 89:e0011121. [PMID: 33820815 DOI: 10.1128/iai.00111-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In this study, we tested the hypothesis that the conserved bacterial IgaA-family protein, GumB, mediates microbial pathogenesis associated with Serratia marcescens ocular infections through regulation of the Rcs stress response system. The role of the Rcs system and bacterial stress response systems for microbial keratitis is not known, and the role of IgaA proteins in mammalian pathogenesis models has only been tested with partial-function allele variants of Salmonella. Here, we observed that an Rcs-activated gumB mutant had a >50-fold reduction in proliferation compared to the wild type within rabbit corneas at 48 h and demonstrated a notable reduction in inflammation based on inflammatory signs, including the absence of hypopyons, and proinflammatory markers measured at the RNA and protein levels. The gumB mutant phenotypes could be complemented by wild-type gumB on a plasmid. We observed that bacteria with an inactivated Rcs stress response system induced high levels of ocular inflammation and restored corneal virulence to the gumB mutant. The high virulence of the ΔrcsB mutant was dependent upon the ShlA cytolysin transporter ShlB. Similar results were found for testing the cytotoxic effects of wild-type and mutant bacteria on a human corneal epithelial cell line in vitro. Together, these data indicate that GumB regulates virulence factor production through the Rcs system, and this overall stress response system is a key mediator of a bacterium's ability to induce vision-threatening keratitis.
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Brothers KM, Harvey SAK, Shanks RMQ. Transcription Factor EepR Is Required for Serratia marcescens Host Proinflammatory Response by Corneal Epithelial Cells. Antibiotics (Basel) 2021; 10:antibiotics10070770. [PMID: 34202642 PMCID: PMC8300729 DOI: 10.3390/antibiotics10070770] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 11/24/2022] Open
Abstract
Relatively little is known about how the corneal epithelium responds to vision-threatening bacteria from the Enterobacterales order. This study investigates the impact of Serratia marcescens on corneal epithelial cell host responses. We also investigate the role of a bacterial transcription factor EepR, which is a positive regulator of S. marcescens secretion of cytotoxic proteases and a hemolytic surfactant. We treated transcriptomic and metabolomic analysis of human corneal limbal epithelial cells with wild-type bacterial secretomes. Our results show increased expression of proinflammatory and lipid signaling molecules, while this is greatly altered in eepR mutant-treated corneal cells. Together, these data support the model that the S. marcescens transcription factor EepR is a key regulator of host-pathogen interactions, and is necessary to induce proinflammatory chemokines, cytokines, and lipids.
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Khayyat AN, Hegazy WAH, Shaldam MA, Mosbah R, Almalki AJ, Ibrahim TS, Khayat MT, Khafagy ES, Soliman WE, Abbas HA. Xylitol Inhibits Growth and Blocks Virulence in Serratia marcescens. Microorganisms 2021; 9:microorganisms9051083. [PMID: 34070043 PMCID: PMC8158113 DOI: 10.3390/microorganisms9051083] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 05/09/2021] [Accepted: 05/12/2021] [Indexed: 12/15/2022] Open
Abstract
Serratia marcescens is an opportunistic nosocomial pathogen and causes wound and burn infections. It shows high resistance to antibiotics and its pathogenicity is mediated by an arsenal of virulence factors. Another therapeutic option to such infections is targeting quorum sensing (QS), which controls the expression of different S. marcescens virulence factors. Prevention of QS can deprive S. marcescens from its bacterial virulence without applying stress on the bacterial growth and facilitates the eradication of the bacteria by immunity. The objective of the current study is to explore the antimicrobial and antivirulence activities of xylitol against S. marcescens. Xylitol could inhibit the growth of S. marcescens. Sub-inhibitory concentrations of xylitol could inhibit biofilm formation, reduce prodigiosin production, and completely block protease activity. Moreover, xylitol decreased swimming motility, swarming motility and increased the sensitivity to hydrogen peroxide. The expression of rsmA, pigP, flhC, flhD fimA, fimC, shlA bsmB, and rssB genes that regulate virulence factor production was significantly downregulated by xylitol. In silico study showed that xylitol could bind with the SmaR receptor by hydrophobic interaction and hydrogen bonding, and interfere with the binding of the natural ligand with SmaR receptor. An in vivo mice survival test confirmed the ability of xylitol to protect mice against the virulence of S. marcescens. In conclusion, xylitol is a growth and virulence inhibitor in S. marcescens and can be employed for the treatment of S. marcescens wound and burn infections.
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Affiliation(s)
- Ahdab N. Khayyat
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (A.N.K.); (A.J.A.); (T.S.I.); (M.T.K.)
| | - Wael A. H. Hegazy
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt;
- Correspondence: ; Tel.: +20-1101188800
| | - Moataz A. Shaldam
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Kafrelsheikh University, Kafr El-Sheikh 33516, Egypt;
| | - Rasha Mosbah
- Infection control Unit, Zagazig University Hospitals, Zagazig University, Zagazig 44519, Egypt;
- Faculty of Oral and Dental medicine, Ahram Canadian University, Giza Governorate 12573, Egypt
| | - Ahmad J. Almalki
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (A.N.K.); (A.J.A.); (T.S.I.); (M.T.K.)
| | - Tarek S. Ibrahim
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (A.N.K.); (A.J.A.); (T.S.I.); (M.T.K.)
- Department of Pharmaceutical Organic Chemistry, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt
| | - Maan T. Khayat
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (A.N.K.); (A.J.A.); (T.S.I.); (M.T.K.)
| | - El-Sayed Khafagy
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-kharj 11942, Saudi Arabia;
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Suez Canal University, Ismailia 41552, Egypt
| | - Wafaa E. Soliman
- Department of Biomedical science, Faculty of Clinical Pharmacy, King Faisal University, Alhofuf, Al-Ahsa 36362, Saudi Arabia;
- Department of Microbiology and Biotechnology, Faculty of Pharmacy, Delta University for Science and Technology, Mansoura 11152, Egypt
| | - Hisham A. Abbas
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig 44519, Egypt;
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Hegazy WAH, Khayat MT, Ibrahim TS, Youns M, Mosbah R, Soliman WE. Repurposing of antidiabetics as Serratia marcescens virulence inhibitors. Braz J Microbiol 2021; 52:627-638. [PMID: 33686563 DOI: 10.1007/s42770-021-00465-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 02/28/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Serratia marcescens becomes an apparent nosocomial pathogen and causes a variety of infections. S. marcescens possess various virulence factors that are regulated by intercellular communication system quorum sensing (QS). Targeting bacterial virulence is a proposed strategy to overcome bacterial resistance. Sitagliptin anti-QS activity has been demonstrated previously and we aimed in this study to investigate the effects of antidiabetic drugs vildagliptin and metformin compared to sitagliptin on S. marcescens pathogenesis. METHODS We assessed the effects of tested drugs in subinhibitory concentrations phenotypically on the virulence factors and genotypically on the virulence encoding genes' expressions. The protection of tested drugs on S. marcescens pathogenesis was performed in vivo. Molecular docking study has been conducted to evaluate the interference capabilities of tested drugs to the SmaR QS receptor. RESULTS Vildagliptin reduced the expression of virulence encoding genes but did not show in vitro or in vivo anti-virulence activities. Metformin reduced the expression of virulence encoding genes and inhibited bacterial virulence in vitro but did not show in vivo protection. Sitagliptin significantly inhibited virulence factors in vitro, reduced the expression of virulence factors and protected mice from S. marcescens. Docking study revealed that sitagliptin is more active than metformin and fully binds to SmaR receptor, whereas vildagliptin had single interaction to SmaR. CONCLUSION The downregulation of virulence genes was not enough to show anti-virulence activities. Hindering of QS receptors may play a crucial role in diminishing bacterial virulence.
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Affiliation(s)
- Wael A H Hegazy
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt.
| | - Maan T Khayat
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
| | - Tarek S Ibrahim
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, King Abdulaziz University, Jeddah, 21589, Saudi Arabia.,Center of Excellence for Drug Research & Pharmaceutical Industries, King Abdulaziz University, Jeddah, 21589, Saudi Arabia.,Department of Pharmaceutical Organic Chemistry, Faculty of Pharmacy, Zagazig University, Zagazig, 44519, Egypt
| | - Mahmoud Youns
- Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, Helwan University, Cairo, Egypt
| | - Rasha Mosbah
- Infection control Unit, Zagazig University Hospitals, Zagazig University, Zagazig, 44519, Egypt
| | - Wafaa E Soliman
- Department of Biomedical Sciences, College of Clinical Pharmacy, King Faisal University, AL AHSA, 31982, Kingdom of Saudi Arabia.,Microbiology and Immunology Department, Faculty of Pharmacy, Delta University for Science and Technology, Gamasa, 35712, Egypt
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12
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Abbas HA, Hegazy WAH. Repurposing anti-diabetic drug "Sitagliptin" as a novel virulence attenuating agent in Serratia marcescens. PLoS One 2020; 15:e0231625. [PMID: 32298346 PMCID: PMC7162429 DOI: 10.1371/journal.pone.0231625] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 03/26/2020] [Indexed: 12/13/2022] Open
Abstract
Background Serratia marcescens is an emerging pathogen that causes a variety of health care associated infections. S. marcescens is equipped with an arsenal of virulence factors such as biofilm formation, swimming and swarming motilities, prodigiosin, protease and others which enable it to initiate and cause the infection. These virulence factors are orchestrated under the umbrella of an intercellular communication system named Quorum sensing (QS). QS allows bacterial population to synchronize the expression of virulence genes upon detection of a chemical signaling molecule. Targeting bacterial virulence is a promising approach to attenuate bacteria and enhances the ability of immune system to eradicate the bacterial infection. Drug repurposing is an advantageous strategy that confers new applications for drugs outside the scope of their original medical use. This promising strategy offers the use of safe approved compounds, which potentially lowers the costs and shortens the time than that needed for development of new drugs. Sitagliptin is dipeptidyl peptidase-4 (DPP-4) inhibitor, is used to treat diabetes mellitus type II as it increases the production of insulin and decreasing the production of glucagon by the pancreas. We aimed in this study to repurpose sitagliptin, investigating the anti-virulence activities of sitagliptin on S. marcescens. Methods The effect of sub-inhibitory concentrations of sitagliptin on virulence factors; protease, prodigiosin, biofilm formation, swimming and swarming motilities was estimated phenotypically. The qRT-PCR was used to show the effect of sitagliptin on the expression of QS-regulated virulence genes. The in-vivo protective activity of sitagliptin on S. marcescens pathogenesis was evaluated on mice. Results Sitagliptin (1 mg/ml) significantly reduced the biofilm formation, swimming and swarming motilities, prodigiosin and protease. The qRT-PCR confirmed the effect on virulence as shown by down regulating the expression of fimA, fimC, flhC, flhD, bsmB, rssB, rsmA, pigP, and shlA genes. Moreover, the in-vivo findings showed the efficient ability of sitagliptin to weaken S. marcescens pathogenesis. Conclusion Sitagliptin is a promising anti-virulence agent against S. marcescens that may be beneficial in the control of healthcare associated infections caused by S. marcescens.
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Affiliation(s)
- Hisham A. Abbas
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
| | - Wael A. H. Hegazy
- Department of Microbiology and Immunology, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
- * E-mail:
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13
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Brothers KM, Stella NA, Shanks RMQ. Biologically active pigment and ShlA cytolysin of Serratia marcescens induce autophagy in a human ocular surface cell line. BMC Ophthalmol 2020; 20:120. [PMID: 32216768 PMCID: PMC7098141 DOI: 10.1186/s12886-020-01387-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 03/12/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The cellular process of autophagy is essential for maintaining the health of ocular tissue. Dysregulation of autophagy is associated with several ocular diseases including keratoconus and macular degeneration. It is known that autophagy can be used to respond to microbial infections and that certain microbes can exploit the autophagic process to their benefit. In this study, a genetic approach was used to identify surface-associated and secreted products generated by the opportunistic pathogen Serratia marcescens involved in activation of autophagy. METHODS A recombinant human corneal limbal epithelial cell line expressing a LC3-GFP fusion protein was challenged with normalized secretomes from wild-type and mutant S. marcescens derivatives. LC3-GFP fluorescence patterns were used to assess the ability of wild-type and mutant bacteria to influence autophagy. Purified prodigiosin was obtained from stationary phase bacteria and used to challenge ocular cells. RESULTS Mutations in the global regulators eepR and gumB genes highly reduced the ability of the bacteria to activate autophagy in corneal cells. This effect was further narrowed down to the secreted cytolysin ShlA and the biologically active pigment prodigiosin. Purified prodigiosin and ShlA from Escherichia coli further supported the role of these factors in activating autophagy in human corneal cells. Additional genetic data indicate a role for flagellin and type I pili, but not the nuclease, S-layer protein, or serratamolide biosurfactant in activation of autophagy. CONCLUSIONS This work identifies specific bacterial components that activate autophagy and give insight into potential host-pathogen interactions or compounds that can be used to therapeutically manipulate autophagy.
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Affiliation(s)
- Kimberly M Brothers
- The Charles T. Campbell Ophthalmic Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh School of Medicine, EEI 1020, 203 Lothrop Street, Pittsburgh, Pennsylvania, 15213, USA
| | - Nicholas A Stella
- The Charles T. Campbell Ophthalmic Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh School of Medicine, EEI 1020, 203 Lothrop Street, Pittsburgh, Pennsylvania, 15213, USA
| | - Robert M Q Shanks
- The Charles T. Campbell Ophthalmic Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh School of Medicine, EEI 1020, 203 Lothrop Street, Pittsburgh, Pennsylvania, 15213, USA.
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14
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Brothers KM, Callaghan JD, Stella NA, Bachinsky JM, AlHigaylan M, Lehner KL, Franks JM, Lathrop KL, Collins E, Schmitt DM, Horzempa J, Shanks RMQ. Blowing epithelial cell bubbles with GumB: ShlA-family pore-forming toxins induce blebbing and rapid cellular death in corneal epithelial cells. PLoS Pathog 2019; 15:e1007825. [PMID: 31220184 PMCID: PMC6586354 DOI: 10.1371/journal.ppat.1007825] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 05/07/2019] [Indexed: 12/18/2022] Open
Abstract
Medical devices, such as contact lenses, bring bacteria in direct contact with human cells. Consequences of these host-pathogen interactions include the alteration of mammalian cell surface architecture and induction of cellular death that renders tissues more susceptible to infection. Gram-negative bacteria known to induce cellular blebbing by mammalian cells, Pseudomonas and Vibrio species, do so through a type III secretion system-dependent mechanism. This study demonstrates that a subset of bacteria from the Enterobacteriaceae bacterial family induce cellular death and membrane blebs in a variety of cell types via a type V secretion-system dependent mechanism. Here, we report that ShlA-family cytolysins from Proteus mirabilis and Serratia marcescens were required to induce membrane blebbling and cell death. Blebbing and cellular death were blocked by an antioxidant and RIP-1 and MLKL inhibitors, implicating necroptosis in the observed phenotypes. Additional genetic studies determined that an IgaA family stress-response protein, GumB, was necessary to induce blebs. Data supported a model where GumB and shlBA are in a regulatory circuit through the Rcs stress response phosphorelay system required for bleb formation and pathogenesis in an invertebrate model of infection and proliferation in a phagocytic cell line. This study introduces GumB as a regulator of S. marcescens host-pathogen interactions and demonstrates a common type V secretion system-dependent mechanism by which bacteria elicit surface morphological changes on mammalian cells. This type V secretion-system mechanism likely contributes bacterial damage to the corneal epithelial layer, and enables access to deeper parts of the tissue that are more susceptible to infection.
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Affiliation(s)
- Kimberly M. Brothers
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA United States of America
- Charles T. Campbell Laboratory of Ophthalmic Microbiology
| | - Jake D. Callaghan
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA United States of America
- Charles T. Campbell Laboratory of Ophthalmic Microbiology
| | - Nicholas A. Stella
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA United States of America
- Charles T. Campbell Laboratory of Ophthalmic Microbiology
| | - Julianna M. Bachinsky
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA United States of America
- Charles T. Campbell Laboratory of Ophthalmic Microbiology
| | - Mohammed AlHigaylan
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA United States of America
- Charles T. Campbell Laboratory of Ophthalmic Microbiology
| | - Kara L. Lehner
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA United States of America
- Charles T. Campbell Laboratory of Ophthalmic Microbiology
| | - Jonathan M. Franks
- Center for Biological Imaging, University of Pittsburgh, Pittsburgh, PA United States of America
| | - Kira L. Lathrop
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA United States of America
| | - Elliot Collins
- Department of Natural Sciences and Mathematics, West Liberty University, West Liberty, WV United States of America
| | - Deanna M. Schmitt
- Department of Natural Sciences and Mathematics, West Liberty University, West Liberty, WV United States of America
| | - Joseph Horzempa
- Department of Natural Sciences and Mathematics, West Liberty University, West Liberty, WV United States of America
| | - Robert M. Q. Shanks
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA United States of America
- Charles T. Campbell Laboratory of Ophthalmic Microbiology
- * E-mail:
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15
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Garcia CJ, Pericleous A, Elsayed M, Tran M, Gupta S, Callaghan JD, Stella NA, Franks JM, Thibodeau PH, Shanks RMQ, Kadouri DE. Serralysin family metalloproteases protects Serratia marcescens from predation by the predatory bacteria Micavibrio aeruginosavorus. Sci Rep 2018; 8:14025. [PMID: 30232396 PMCID: PMC6145908 DOI: 10.1038/s41598-018-32330-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 09/03/2018] [Indexed: 12/16/2022] Open
Abstract
Micavibrio aeruginosavorus is an obligate Gram-negative predatory bacterial species that feeds on other Gram-negative bacteria by attaching to the surface of its prey and feeding on the prey's cellular contents. In this study, Serratia marcescens with defined mutations in genes for extracellular cell structural components and secreted factors were used in predation experiments to identify structures that influence predation. No change was measured in the ability of the predator to prey on S. marcescens flagella, fimbria, surface layer, prodigiosin and phospholipase-A mutants. However, higher predation was measured on S. marcescens metalloprotease mutants. Complementation of the metalloprotease gene, prtS, into the protease mutant, as well as exogenous addition of purified serralysin metalloprotease, restored predation to wild type levels. Addition of purified serralysin also reduced the ability of M. aeruginosavorus to prey on Escherichia coli. Incubating M. aeruginosavorus with purified metalloprotease was found to not impact predator viability; however, pre-incubating prey, but not the predator, with purified metalloprotease was able to block predation. Finally, using flow cytometry and fluorescent microscopy, we were able to confirm that the ability of the predator to bind to the metalloprotease mutant was higher than that of the metalloprotease producing wild-type. The work presented in this study shows that metalloproteases from S. marcescens could offer elevated protection from predation.
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Affiliation(s)
- Carlos J Garcia
- Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ, 07103, USA
| | - Androulla Pericleous
- Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ, 07103, USA
| | - Mennat Elsayed
- Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ, 07103, USA
| | - Michael Tran
- Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ, 07103, USA
| | - Shilpi Gupta
- Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ, 07103, USA
| | - Jake D Callaghan
- Department of Ophthalmology, Charles T. Campbell Laboratory of Ophthalmic Microbiology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Nicholas A Stella
- Department of Ophthalmology, Charles T. Campbell Laboratory of Ophthalmic Microbiology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Jonathan M Franks
- Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Patrick H Thibodeau
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, 15221, USA
| | - Robert M Q Shanks
- Department of Ophthalmology, Charles T. Campbell Laboratory of Ophthalmic Microbiology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Daniel E Kadouri
- Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ, 07103, USA.
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16
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Hage-Hülsmann J, Grünberger A, Thies S, Santiago-Schübel B, Klein AS, Pietruszka J, Binder D, Hilgers F, Domröse A, Drepper T, Kohlheyer D, Jaeger KE, Loeschcke A. Natural biocide cocktails: Combinatorial antibiotic effects of prodigiosin and biosurfactants. PLoS One 2018; 13:e0200940. [PMID: 30024935 PMCID: PMC6053208 DOI: 10.1371/journal.pone.0200940] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Accepted: 07/05/2018] [Indexed: 11/18/2022] Open
Abstract
Bacterial secondary metabolites are naturally produced to prevail amongst competitors in a shared habitat and thus represent a valuable source for antibiotic discovery. The transformation of newly discovered antibiotic compounds into effective drugs often requires additional surfactant components for drug formulation. Nature may also provide blueprints in this respect: A cocktail of two compounds consisting of the antibacterial red pigment prodigiosin and the biosurfactant serrawettin W1 is naturally produced by the bacterium Serratia marcescens, which occurs in highly competitive habitats including soil. We show here a combinatorial antibacterial effect of these compounds, but also of prodigiosin mixed with other (bio)surfactants, against the soil-dwelling bacterium Corynebacterium glutamicum taken as a model target bacterium. Prodigiosin exerted a combinatorial inhibitory effect with all tested surfactants in a disk diffusion assay which was especially pronounced in combination with N-myristoyltyrosine. Minimal inhibitory and bactericidal concentrations (MIC and MBC) of the individual compounds were 2.56 μg/mL prodigiosin and 32 μg/mL N-myristoyltyrosine, and the MIC of prodigiosin was decreased by 3 orders of magnitude to 0.005 μg/mL in the presence of 16 μg/mL N-myristoyltyrosine, indicative of synergistic interaction. Investigation of bacterial survival revealed similar combinatorial effects; moreover, antagonistic effects were observed at higher compound concentrations. Finally, the investigation of microcolony formation under combined application of concentrations just below the MBC revealed heterogeneity of responses with cell death or delayed growth. In summary, this study describes the combinatorial antibacterial effects of microbial biomolecules, which may have ecological relevance by inhibiting cohabiting species, but shall furthermore inspire drug development in the combat of infectious disease.
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Affiliation(s)
- Jennifer Hage-Hülsmann
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Alexander Grünberger
- IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
- Multiscale Bioengineering, Bielefeld University, Bielefeld, Germany
| | - Stephan Thies
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich, Jülich, Germany
| | - Beatrix Santiago-Schübel
- Central Division of Analytical Chemistry ZEA-3: Analytik/Biospec, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Andreas Sebastian Klein
- Institute of Bioorganic Chemistry, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Jörg Pietruszka
- IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
- Institute of Bioorganic Chemistry, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Dennis Binder
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Fabienne Hilgers
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Andreas Domröse
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Thomas Drepper
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Dietrich Kohlheyer
- IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
- Aachener Verfahrenstechnik (AVT.MSB), RWTH Aachen University, Aachen, Germany
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
- IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Anita Loeschcke
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
- Bioeconomy Science Center (BioSC), Forschungszentrum Jülich, Jülich, Germany
- * E-mail:
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17
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Brothers KM, Kowalski RP, Tian S, Kinchington PR, Shanks RMQ. Bacteria induce autophagy in a human ocular surface cell line. Exp Eye Res 2017; 168:12-18. [PMID: 29288646 DOI: 10.1016/j.exer.2017.12.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 12/24/2017] [Indexed: 12/18/2022]
Abstract
Autophagy protects cells from intracellular pathogens, but can be exploited by some infectious agents to their benefit. Currently it is not known if bacteria induce autohpagy in cells of the cornea. The goal of this study was to develop an ocular surface autophagy reporter cell line and determine whether ocular bacterial pathogens influence host responses through autophagy induction. The cell line was made using lentivirus transduction of an LC3-GFP fusion protein in human corneal limbal epithelial (HCLE) cells. LC3-GFP puncta in HCLEs were induced by rapamycin and ammonium chloride treatments, and prevented by the autophagy inhibitors 3-methyladenine (3'MA) and bafilomycin. Importantly, secretomes from Escherichia coli, Serratia marcescens, Staphylococcus aureus, methicillin sensitive (MSSA) and resistant (MRSA), were found to induce autophagy, whereas other bacteria, including Acinetobacter baumannii, Achromobacter xylosoxidans, Enterococcus faecalis, Klebsiella pneumoniae, Moraxella sp., and Stenotrophomonas maltophilia, did not. Our data indicates differences between tested ocular isolates of MRSA and MSSA in the activation of autophagy. HCLEs treated with 3'MA were slightly more susceptible to cytotoxic factors produced by S. marcescens and MRSA keratitis isolates, by contrast, bafilomycin A1 treatment caused no difference. This work demonstrates the successful development and validation of an autophagy reporter corneal cell line and indicates differences between ocular bacterial isolates in the activation of autophagy.
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Affiliation(s)
- Kimberly M Brothers
- The Charles T. Campbell Ophthalmic Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Regis P Kowalski
- The Charles T. Campbell Ophthalmic Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Shenghe Tian
- The Charles T. Campbell Ophthalmic Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Paul R Kinchington
- The Charles T. Campbell Ophthalmic Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Robert M Q Shanks
- The Charles T. Campbell Ophthalmic Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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18
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Shanks RMQ, Stella NA, Lahr RM, Aston MA, Brothers KM, Callaghan JD, Sigindere C, Liu X. Suppressor analysis of eepR mutant defects reveals coordinate regulation of secondary metabolites and serralysin biosynthesis by EepR and HexS. MICROBIOLOGY-SGM 2017; 163:280-288. [PMID: 28270264 DOI: 10.1099/mic.0.000422] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The EepR transcription factor positively regulates secondary metabolites and tissue-damaging metalloproteases. To gain insight into mechanisms by which EepR regulates pigment and co-regulated factors, genetic suppressor analysis was performed. Suppressor mutations that restored pigment to the non-pigmented ∆eepR mutant mapped to the hexS ORF. Mutation of hexS also restored haemolysis, swarming motility and protease production to the eepR mutant. HexS is a known direct and negative regulator of secondary metabolites in Serratia marcescens and is a LysR family regulator and an orthologue of LrhA. Here, we demonstrate that HexS directly controls eepR and the serralysin gene prtS. EepR was shown to directly regulate eepR expression but indirectly regulate hexS expression. Together, these data indicate that EepR and HexS oppose each other in controlling stationary phase-associated molecules and enzymes.
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Affiliation(s)
- Robert M Q Shanks
- Charles T. Campbell Ophthalmic Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh Medical School, Pittsburgh, PA, USA
| | - Nicholas A Stella
- Charles T. Campbell Ophthalmic Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh Medical School, Pittsburgh, PA, USA
| | - Roni M Lahr
- Present address: Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
- Charles T. Campbell Ophthalmic Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh Medical School, Pittsburgh, PA, USA
| | - Marissa A Aston
- Present address: Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Charles T. Campbell Ophthalmic Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh Medical School, Pittsburgh, PA, USA
| | - Kimberly M Brothers
- Charles T. Campbell Ophthalmic Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh Medical School, Pittsburgh, PA, USA
| | - Jake D Callaghan
- Charles T. Campbell Ophthalmic Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh Medical School, Pittsburgh, PA, USA
| | - Cihad Sigindere
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Xinyu Liu
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
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19
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Stella NA, Callaghan JD, Zhang L, Brothers KM, Kowalski RP, Huang JJ, Thibodeau PH, Shanks RMQ. SlpE is a calcium-dependent cytotoxic metalloprotease associated with clinical isolates of Serratia marcescens. Res Microbiol 2017; 168:567-574. [PMID: 28366837 PMCID: PMC5503780 DOI: 10.1016/j.resmic.2017.03.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 03/08/2017] [Accepted: 03/22/2017] [Indexed: 01/15/2023]
Abstract
Serralysin-like proteases are found in a wide variety of bacteria. These metalloproteases are frequently implicated in virulence and are members of the widely conserved RTX-toxin family. We identified a serralysin-like protease in the genome of a clinical isolate of Serratia marcescens that is highly similar to the canonical serralysin protein, PrtS. This gene was named serralysin-like protease E, SlpE, and was found in the majority (67%) of tested clinical isolates, but was absent from most tested non-clinical isolates including the insect pathogen and reference S. marcescens strain Db11. Purified recombinant SlpE exhibited calcium-dependent protease activity similar to metalloproteases PrtS and SlpB. Induction of slpE in the low-protease-producing S. marcescens strain PIC3611 highly elevated extracellular protease activity, and extracellular secretion required the lipD type 1 secretion system gene. Transcription of slpE was highly reduced in an eepR transcription factor mutant. Mutation of the slpE gene in a highly proteolytic clinical isolate reduced its protease activity, and evidence suggests that SlpE confers cytotoxicity of S. marcescens to the A549 airway carcinoma cell line. Together, these data reveal SlpE to be an EepR-regulated cytotoxic metalloprotease associated with clinical isolates of an important opportunistic pathogen.
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Affiliation(s)
- Nicholas A Stella
- Charles T. Campbell Laboratory of Ophthalmic Microbiology, Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Jake D Callaghan
- Charles T. Campbell Laboratory of Ophthalmic Microbiology, Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Liang Zhang
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Kimberly M Brothers
- Charles T. Campbell Laboratory of Ophthalmic Microbiology, Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Regis P Kowalski
- Charles T. Campbell Laboratory of Ophthalmic Microbiology, Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Jean J Huang
- Department of Biology, Olin College, Needham, MA 02492, USA
| | - Patrick H Thibodeau
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Robert M Q Shanks
- Charles T. Campbell Laboratory of Ophthalmic Microbiology, Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA 15219, USA.
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Predatory bacteria are nontoxic to the rabbit ocular surface. Sci Rep 2016; 6:30987. [PMID: 27527833 PMCID: PMC4985815 DOI: 10.1038/srep30987] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 07/08/2016] [Indexed: 02/07/2023] Open
Abstract
Given the increasing emergence of antimicrobial resistant microbes and the near absent development of new antibiotic classes, innovative new therapeutic approaches to address this global problem are necessary. The use of predatory bacteria, bacteria that prey upon other bacteria, is gaining interest as an "out of the box" therapeutic treatment for multidrug resistant pathogenic bacterial infections. Before a new antimicrobial agent is used to treat infections, it must be tested for safety. The goal of this study was to test the tolerability of bacteria on the ocular surface using in vitro and in vivo models. Predatory bacteria Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus were found to be non-toxic to human corneal stromal keratocytes in vitro; however, they did induce production of the proinflammatory chemokine IL-8 but not IL-1β. Predatory bacteria did not induce inflammation on the ocular surface of rabbit eyes, with and without corneal epithelial abrasions. Unlike a standard of care antibiotic vancomycin, predatory bacteria did not inhibit corneal epithelial wound healing or increase clinical inflammatory signs in vivo. Together these data support the safety of predatory bacteria on the ocular surface, but future studies are warranted regarding the use predatory bacteria in deeper tissues of the eye.
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