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Ku RH, Li LH, Liu YF, Hu EW, Lin YT, Lu HF, Yang TC. Implication of the σ E Regulon Members OmpO and σ N in the Δ ompA299-356-Mediated Decrease of Oxidative Stress Tolerance in Stenotrophomonas maltophilia. Microbiol Spectr 2023; 11:e0108023. [PMID: 37284772 PMCID: PMC10433810 DOI: 10.1128/spectrum.01080-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 05/16/2023] [Indexed: 06/08/2023] Open
Abstract
Outer membrane protein A (OmpA) is the most abundant porin in bacterial outer membranes. KJΔOmpA299-356, an ompA C-terminal in-frame deletion mutant of Stenotrophomonas maltophilia KJ, exhibits pleiotropic defects, including decreased tolerance to menadione (MD)-mediated oxidative stress. Here, we elucidated the underlying mechanism of the decreased MD tolerance mediated by ΔompA299-356. The transcriptomes of wild-type S. maltophilia and the KJΔOmpA299-356 mutant strain were compared, focusing on 27 genes known to be associated with oxidative stress alleviation; however, no significant differences were identified. OmpO was the most downregulated gene in KJΔOmpA299-356. KJΔOmpA299-356 complementation with the chromosomally integrated ompO gene restored MD tolerance to the wild-type level, indicating the role of OmpO in MD tolerance. To further clarify the possible regulatory circuit involved in ompA defects and ompO downregulation, σ factor expression levels were examined based on the transcriptome results. The expression levels of three σ factors were significantly different (downregulated levels of rpoN and upregulated levels of rpoP and rpoE) in KJΔOmpA299-356. Next, the involvement of the three σ factors in the ΔompA299-356-mediated decrease in MD tolerance was evaluated using mutant strains and complementation assays. rpoN downregulation and rpoE upregulation contributed to the ΔompA299-356-mediated decrease in MD tolerance. OmpA C-terminal domain loss induced an envelope stress response. Activated σE decreased rpoN and ompO expression levels, in turn decreasing swimming motility and oxidative stress tolerance. Finally, we revealed both the ΔompA299-356-rpoE-ompO regulatory circuit and rpoE-rpoN cross regulation. IMPORTANCE The cell envelope is a morphological hallmark of Gram-negative bacteria. It consists of an inner membrane, a peptidoglycan layer, and an outer membrane. OmpA, an outer membrane protein, is characterized by an N-terminal β-barrel domain that is embedded in the outer membrane and a C-terminal globular domain that is suspended in the periplasmic space and connected to the peptidoglycan layer. OmpA is crucial for the maintenance of envelope integrity. Stress resulting from the destruction of envelope integrity is sensed by extracytoplasmic function (ECF) σ factors, which induce responses to various stressors. In this study, we revealed that loss of the OmpA-peptidoglycan (PG) interaction causes peptidoglycan and envelope stress while simultaneously upregulating σP and σE expression levels. The outcomes of σP and σE activation are different and are linked to β-lactam and oxidative stress tolerance, respectively. These findings establish that outer membrane proteins (OMPs) play a critical role in envelope integrity and stress tolerance.
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Affiliation(s)
- Ren-Hsuan Ku
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Li-Hua Li
- Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- School of Medical Laboratory Science and Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Yi-Fu Liu
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - En-Wei Hu
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yi-Tsung Lin
- Division of Infectious Diseases, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Department of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Hsu-Feng Lu
- Department of Medical Laboratory Science and Biotechnology, Asia University, Taichung, Taiwan
| | - Tsuey-Ching Yang
- Department of Biotechnology and Laboratory Science in Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
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Wang L, Forsythe SJ, Yang X, Fu S, Man C, Jiang Y. Invited review: Stress resistance of Cronobacter spp. affecting control of its growth during food production. J Dairy Sci 2021; 104:11348-11367. [PMID: 34364644 DOI: 10.3168/jds.2021-20591] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 06/17/2021] [Indexed: 11/19/2022]
Abstract
Members of the Cronobacter genus include food-borne pathogens that can cause infections in infants, with a mortality rate as high as 40 to 80%. The high fatality rate of Cronobacter and its isolation from numerous types of food, especially from powdered infant formula, demonstrate the serious nature of this organism. The source tracking of Cronobacter spp. and the analysis of high-frequency species from different sources are helpful for a more targeted control. Furthermore, the persistence during food processing and storage may be attributed to strong resistance of Cronobacter spp. to environment stresses such as heat, pH, and desiccation. There are many factors that support the survival of Cronobacter spp. in harsh environments, such as some genes, regulatory systems, and biofilms. Advanced detection technology is helpful for the strict monitoring of Cronobacter spp. In addition to the traditional heat treatment, many new control techniques have been developed, and the ability to control Cronobacter spp. has been demonstrated. The control of this bacteria is required not only during manufacture, but also through the selection of packaging methods to reduce postprocessing contamination. At the same time, the effect of inactivation methods on product quality and safety must be considered. This review considers the advances in our understanding of environmental stress response in Cronobacter spp. with special emphasis on its implications in food processing.
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Affiliation(s)
- Lihan Wang
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, Harbin, China, 150030
| | - Stephen J Forsythe
- Foodmicrobe.com, Adams Hill, Keyworth, Nottingham, United Kingdom, NG12 5GY
| | - Xinyan Yang
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, Harbin, China, 150030
| | - Shiqian Fu
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, Harbin, China, 150030
| | - Chaoxin Man
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, Harbin, China, 150030.
| | - Yujun Jiang
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, Harbin, China, 150030.
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Ling N, Ou D, Shen Y, Zhang D, Wang Y, Tong L, Ding Y, Wang J, Yang X, Zhang J, Wu Q, Ye Y. Proteomics analysis mediated by quorum sensing luxS involved in oxidative stress in Cronobacter malonaticus. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.111576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Xu Z, Liu Z, Soteyome T, Hua J, Zhang L, Yuan L, Ye Y, Cai Z, Yang L, Chen L, Harro JM, Kjellerup BV, Liu J, Li Y. Impact of pmrA on Cronobacter sakazakii planktonic and biofilm cells: A comprehensive transcriptomic study. Food Microbiol 2021; 98:103785. [PMID: 33875213 DOI: 10.1016/j.fm.2021.103785] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 12/30/2020] [Accepted: 03/05/2021] [Indexed: 10/21/2022]
Abstract
Cronobacter sakazakii is an emerging opportunistic foodborne pathogen causing rare but severe infections in neonates. Furthermore, the formation of biofilm allows C. sakazakii to persist in different environments. We have demonstrated that the mutator phenotype ascribed to deficiency of the pmrA gene results in more biomass in the first 24 h but less during the post maturation stage (7-14 d) compared with BAA 894. The present study aimed to investigate the regulatory mechanism modulating biofilm formation due to pmrA mutation. The transcriptomic analyses of BAA 894 and s-3 were performed by RNA-sequencing on planktonic and biofilm cells collected at different time points. According to the results, when comparing biofilm to planktonic cells, expression of genes encoding outer membrane proteins, lysozyme, etc. were up-regulated, with LysR family transcriptional regulators, periplasmic proteins, etc. down-regulated. During biofilm formation, cellulose synthase operon genes, flagella-related genes, etc. played essential roles in different stages. Remarkably, pmrA varies the expression of a number of genes related to motility, biofilm formation, and antimicrobial resistance, including srfB, virK, mviM encoding virulence factor, flgF, fliN, etc. encoding flagellar assembly, and marA, ramA, etc. encoding AraC family transcriptional regulators in C. sakazakii. This study provides valuable insights into transcriptional regulation of C. sakazakii pmrA mutant during biofilm formation.
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Affiliation(s)
- Zhenbo Xu
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, 510640, China; Department of Clinical Pharmacy and Translational Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, 38103, USA; Home Economics Technology, Rajamangala University of Technology Phra Nakhon, Bangkok, Thailand; National Institute of Fundamental Studies, Hantana Road, Kandy, Sri Lanka; Overseas Expertise Introduction Center for Discipline Innovation of Food Nutrition and Human Health (111 Center), Guangzhou, 510640, China
| | - Ziqi Liu
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, 510640, China
| | - Thanapop Soteyome
- National Institute of Fundamental Studies, Hantana Road, Kandy, Sri Lanka
| | - Jingjing Hua
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, China
| | - Liang Zhang
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, China.
| | - Lei Yuan
- College of Food Science and Engineering, Yangzhou University, Yangzhou, China
| | - Yanrui Ye
- School of Biological Science and Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Zhao Cai
- School of Medicine, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China
| | - Liang Yang
- School of Medicine, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China
| | - Ling Chen
- School of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou, 510640, China
| | - Janette M Harro
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD, 21201, USA
| | - Birthe Veno Kjellerup
- Department of Civil and Environmental Engineering, University of Maryland, College Park, MD, 20742, USA
| | - Junyan Liu
- Department of Civil and Environmental Engineering, University of Maryland, College Park, MD, 20742, USA
| | - Yanyan Li
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 18 Shilongshan Road, Xihu District, Hangzhou, 310024, Zhejiang Province, China.
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Ke A, Parreira VR, Goodridge L, Farber JM. Current and Future Perspectives on the Role of Probiotics, Prebiotics, and Synbiotics in Controlling Pathogenic Cronobacter Spp. in Infants. Front Microbiol 2021; 12:755083. [PMID: 34745060 PMCID: PMC8567173 DOI: 10.3389/fmicb.2021.755083] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 09/27/2021] [Indexed: 12/14/2022] Open
Abstract
Cronobacter species, in particular C. sakazakii, is an opportunistic bacterial pathogen implicated in the development of potentially debilitating illnesses in infants (<12months old). The combination of a poorly developed immune system and gut microbiota put infants at a higher risk of infection compared to other age groups. Probiotics and prebiotics are incorporated in powdered infant formula and, in addition to strengthening gut physiology and stimulating the growth of commensal gut microbiota, have proven antimicrobial capabilities. Postbiotics in the cell-free supernatant of a microbial culture are derived from probiotics and can also exert health benefits. Synbiotics, a mixture of probiotics and prebiotics, may provide further advantages as probiotics and gut commensals degrade prebiotics into short-chain fatty acids that can provide benefits to the host. Cell-culture and animal models have been widely used to study foodborne pathogens, but sophisticated gut models have been recently developed to better mimic the gut conditions, thus giving a more accurate representation of how various treatments can affect the survival and pathogenicity of foodborne pathogens. This review aims to summarize the current understanding on the connection between Cronobacter infections and infants, as well as highlight the potential efficacy of probiotics, prebiotics, and synbiotics in reducing invasive Cronobacter infections during early infancy.
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Aly MA, Domig KJ, Kneifel W, Reimhult E. Whole Genome Sequencing-Based Comparison of Food Isolates of Cronobacter sakazakii. Front Microbiol 2019; 10:1464. [PMID: 31333604 PMCID: PMC6615433 DOI: 10.3389/fmicb.2019.01464] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 06/11/2019] [Indexed: 12/13/2022] Open
Abstract
Cronobacter sakazakii is an emerging foodborne pathogen, which is linked to life-threatening infections causing septicemia, meningitis, and necrotizing enterocolitis. These infections have been epidemiologically connected to ingestion of contaminated reconstituted powder infant formula. Even at low water activity C. sakazakii can survive for a long time; it is capable of protective biofilm formation and occasionally shows high virulence and pathogenicity even following stressful environmental conditions. Hence it is a challenging task for the food industry to control contamination of food ingredients and products through the entire production chain, since an increasing number of severe food-related outbreaks of C. sakazakii infections has been observed. The seemingly great capability of C. sakazakii to survive even strict countermeasures combined with its prevalence in many food ingredients requires a greater in depth understanding of its virulence factors to master the food safety issues related to this organism. In this context, we present the whole genome sequence (WGS) of two different C. sakazakii isolated from skimmed milk powder (C7) and ready-to-eat salad mix (C8), respectively. These are compared to other, already sequenced, C. sakazakii genomes. Sequencing of the fusA allele revealed that both isolates were C. sakazakii. We investigated the molecular characteristics of both isolates relevant for genes associated with pathogenesis and virulence factors, resistance to stressful environmental conditions (e.g., osmotic and heat), survival in desiccation as well as conducted a comparative genomic analysis. By using multi-locus sequence typing (MLST), the genetic type of both isolates is assessed and the number of unique genes is determined. DNA of C. sakazakii C8 is shown to hold a novel and unique sequence type; the number of unique genes identified in the genomic sequence of C. sakazakii C7 and C8 were 109 and 188, respectively. Some of the determined unique genes such as the rhs and VgrG genes are linked to the Type VI Secretion System cluster, which is associated with pathogenicity and virulence factors. Moreover, seven genes encoding for multi-drug resistance were found in both isolates. The finding of a number of genes linked to producing capsules and biofilm are likely related to the observed resistance to desiccation.
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Affiliation(s)
- Mohamed A Aly
- Department of Nanobiotechnology, Institute for Biologically Inspired Materials, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria.,Department of Food Science, Faculty of Agriculture, Ain Shams University, Cairo, Egypt
| | - Konrad J Domig
- Department of Food Science and Technology, Institute of Food Science, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
| | - Wolfgang Kneifel
- Department of Food Science and Technology, Institute of Food Science, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
| | - Erik Reimhult
- Department of Nanobiotechnology, Institute for Biologically Inspired Materials, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
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