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Han M, Chen Z, He P, Li Z, Chen Q, Tong Z, Wang M, Du H, Zhang H. YgiM may act as a trigger in the sepsis caused by Klebsiella pneumoniae through the membrane-associated ceRNA network. Front Genet 2022; 13:973145. [PMID: 36212144 PMCID: PMC9537587 DOI: 10.3389/fgene.2022.973145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 09/07/2022] [Indexed: 11/27/2022] Open
Abstract
Sepsis is one of the diseases that can cause serious mortality. In E. coli, an inner membrane protein YgiM encoded by gene ygiM can target the eukaryotic peroxisome. Peroxisome is a membrane-enclosed organelle associated with the ROS metabolism and was reported to play the key role in immune responses and inflammation during the development of sepsis. Klebsiella pneumoniae (K. pneumoniae) is one of the important pathogens causing sepsis. However, the function of gene vk055_4013 which is highly homologous to ygiM of E. coli has not been demonstrated in K. pneumoniae. In this study, we prepared ΔygiM of K. pneumoniae ATCC43816, and found that the deletion of ygiM did not affect bacterial growth and mouse mortality in the mouse infection model. Interestingly, ΔygiM not only resulted in reduced bacterial resistance to macrophages, but also attenuated pathological manifestations in mouse organs. Furthermore, based on the data of Gene Expression Omnibus, the expression profiles of micro RNAs (miRNAs) and messenger RNAs (mRNAs) in the serum of 44 sepsis patients caused by K. pneumoniae infection were analyzed, and 11 differently expressed miRNAs and 8 DEmRNAs associated with the membrane function were found. Finally, the membrane-associated competing endogenous RNAs (ceRNAs) network was constructed. In this ceRNAs network, DEmiRNAs (hsa-miR-7108-5p, hsa-miR-6780a-5p, hsa-miR-6756-5p, hsa-miR-4433b-3p, hsa-miR-3652, hsa-miR-342-3p, hsa-miR-32-5p) and their potential downstream target DEmRNAs (VNN1, CEACAM8, PGLYRP1) were verified in the cell model infected by wild type and ΔygiM of K. pneumoniae, respectively. Taken together, YgiM may trigger the sepsis caused by K. pneumoniae via membrane-associated ceRNAs. This study provided new insights into the role of YgiM in the process of K. pneumoniae induced sepsis.
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Affiliation(s)
- Mingxiao Han
- Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Zhihao Chen
- Department of Orthopedics, The Second Affiliated Hospital of Soochow University, Suzhou, China
- Department of Musculoskeletal Oncology, Sun Yat-sen University Cancer Center, Guangzhou, China
- State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center of Cancer Medicine, Guangzhou, China
| | - Ping He
- Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, China
- Department of Clinical Laboratory, Sichuan Province Science City Hospital, Chengdu, China
| | - Ziyuan Li
- Department of Orthopedics, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Qi Chen
- Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Zelei Tong
- Department of Orthopedics, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Min Wang
- Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Hong Du
- Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, China
- *Correspondence: Haifang Zhang, , ; Hong Du,
| | - Haifang Zhang
- Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, China
- *Correspondence: Haifang Zhang, , ; Hong Du,
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Paes J, Kepler R, Gonçalves RF, Berte FK, Virginio VG, Benitez LB, Rott MB. Amoebal coculture and enrichment methods as a proposal for water quality control in Brazil. Acta Trop 2021; 223:106074. [PMID: 34358510 DOI: 10.1016/j.actatropica.2021.106074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 07/22/2021] [Accepted: 07/26/2021] [Indexed: 11/27/2022]
Abstract
Free living amoebae (FLA) can be found in different environments, where they feed on diverse microorganisms. Some bacteria preyed by FLA are called amoeba-resistant bacteria (ARB), as they can resist to lysosomal fusion and are capable of multiplying and evading FLA after internalization, propagating in the environment. Despite the health risks due to the existence of pathogenic and opportunistic species that are ARB and the pathogenicity of some FLA species, there are no water quality protocols to analyze the presence of ARB or FLA. In this sense, our study aimed to isolate FLA through amoebal enrichment and to identify ARB using amoebal coculture in water samples from a public park and two hospitals in southern Brazil. As a result, 9 different microorganisms genera have been identified through amoebal coculture, including fastidious Legionella spp. and Bosea vestrisii. From the positive samples for FLA, by amoebal enrichment, Acanthamoeba spp., Vermamoeba vermiformis and Naegleria spp. were identified in 14 amoebic isolates. The methodologies used in this work proved to be effective as simple and low-cost methods to be used in the implementation in water quality control of anthropogenic environments.
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Environmental Free-Living Amoebae Can Predate on Diverse Antibiotic-Resistant Human Pathogens. Appl Environ Microbiol 2021; 87:e0074721. [PMID: 34232736 PMCID: PMC8388808 DOI: 10.1128/aem.00747-21] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Here, we sought to test the resistance of human pathogens to unaltered environmental free-living amoebae. Amoebae are ubiquitous eukaryotic microorganisms and important predators of bacteria. Environmental amoebae have also been proposed to serve as both potential reservoirs and training grounds for human pathogens. However, studies addressing their relationships with human pathogens often rely on a few domesticated amoebae that have been selected to feed on rich medium, thereby possibly overestimating the resistance of pathogens to these predatory phagocytes. From an open-air composting site, we recovered over 100 diverse amoebae that were able to feed on Acinetobacter baumannii and Klebsiella pneumoniae. In a standardized and quantitative assay for predation, the isolated amoebae showed a broad predation spectrum, killing clinical isolates of A. baumannii, K. pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus. Interestingly, A. baumannii, which was previously reported to resist predation by laboratory strains of Acanthamoeba, was efficiently consumed by closely related environmental amoebae. The isolated amoebae were capable of feeding on highly virulent carbapenem-resistant or methicillin-resistant clinical isolates. In conclusion, the natural environment is a rich source of amoebae with broad-spectrum bactericidal activities, including against antibiotic-resistant isolates. IMPORTANCE Free-living amoebae have been proposed to play an important role in hosting and disseminating various human pathogens. The resistance of human pathogens to predation by amoebae is often derived from in vitro experiments using model amoebae. Here, we sought to isolate environmental amoebae and to test their predation on diverse human pathogens, with results that challenge conclusions based on model amoebae. We found that the natural environment is a rich source of diverse amoebae with broad-spectrum predatory activities against human pathogens, including highly virulent and antibiotic-resistant clinical isolates.
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Increased Sensitivity of Amoeba-Grown Francisella Species to Disinfectants. Microorganisms 2020; 8:microorganisms8091260. [PMID: 32825290 PMCID: PMC7569850 DOI: 10.3390/microorganisms8091260] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/11/2020] [Accepted: 08/18/2020] [Indexed: 11/17/2022] Open
Abstract
Francisella tularensis is a highly infectious, intracellular bacterium and it is the causative agent of tularemia. The bacterium has been isolated from more than 250 species, including protozoa. Previous studies have shown that the growth of Legionella pneumophila within the amoeba results in a dramatic increase in the resistance to disinfectants. Since Francisella persists in the environment for years, this study investigates whether Acanthamoeba castellanii-grown F. novicida exhibits an alteration in the resistance to disinfectants. The disinfectants used are didecyldimethylammonium chloride (DDAC) combined with isopropyl alcohol (D1), benzalkonium chloride combined with DDAC and formic acid (D2), and polyhexamethylene biguanide (PHMB, D3). The effect of disinfectants on the bacterial viability is determined by a colony-forming unit (CFU), by transmission electron microscopy (TEM), by fluorescence microscopy, and the damage of the bacterial membrane. Our data has shown that only a one-log10 loss in bacterial viability is exhibited upon treatment of agar-grown Francisella, while in amoeba-grown Francisella there was a three-log10 difference with D3. The D1 disinfectant sterilized the bacteria within 10 s. The treatment of agar-grown F. novicida with D2 reduces bacterial viability by seven-log10 within 10 s and 15 min, respectively. Surprisingly, the treatment of amoeba-grown F. novicida with D2 results in a total loss of bacterial viability. In conclusion, A. castellanii-grown F. novicida is more susceptible to many disinfectants.
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Kaboré OD, Loukil A, Godreuil S, Drancourt M. Co-culture models illustrate the digestion of Gemmata spp. by phagocytes. Sci Rep 2018; 8:13311. [PMID: 30190504 PMCID: PMC6127157 DOI: 10.1038/s41598-018-31667-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 08/10/2018] [Indexed: 11/25/2022] Open
Abstract
Gemmata spp. bacteria thrive in the same aquatic environments as free-living amoebae. DNA-based detection of Gemmata spp. sequences in the microbiota of the human digestive tract and blood further questioned the susceptibility of Gemmata spp. to phagocytes. Here, Gemmata obscuriglobus and Gemmata massiliana were co-cultured with the amoebae Acanthamoeba polyphaga, Acanthamoeba castellanii, Acanthamoeba griffini and THP-1 macrophage-like phagocytes. All experiments were performed in five independant replicates. The ratio amoeba/bacteria was 1:20 and the ratio THP-1/bacteria was 1:10. After a 2-hour co-culture, extracellular bacteria were killed by kanamycin or amikacin and eliminated. The intracellular location of Gemmata bacteria was specified by confocal microscopy. Microscopic enumerations and culture-based enumerations of colony-forming units were performed at T = 0, 1, 2, 3, 4, 8, 16, 24, 48 and 72 hours post-infection. Then, Gemmata bacteria were engulfed into the phagocytes’ cytoplasmic vacuoles, more than (98 ± 2)% of Gemmata bacteria, compared to controls, were destroyed by phagocytic cells after a 48-h co-culture according to microscopy and culture results, and no positive culture was observed at T = 72-hours. Under our co-culture conditions, Gemmata bacteria were therefore susceptible to the environmental and host phagocytes here investigated. These data suggest that these Acanthamoeba species and THP-1 cells cannot be used to isolate G. massiliana and G. obscuriglobus under the co-culture conditions applied in this study. Although the THP-1 response can point towards potential responses that might occur in vivo, these responses should first bevalidated by in vivo studies to draw definite conclusions.
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Affiliation(s)
- Odilon D Kaboré
- Aix Marseille Univ., IRD, MEPHI, IHU Méditerranée Infection, Marseille, France
| | - Ahmed Loukil
- Aix Marseille Univ., IRD, MEPHI, IHU Méditerranée Infection, Marseille, France
| | - Sylvain Godreuil
- Université de Montpellier UMR 1058 UMR MIVEGEC, UMR IRD 224-CNRS Inserm, 1058, Montpellier, France
| | - Michel Drancourt
- Aix Marseille Univ., IRD, MEPHI, IHU Méditerranée Infection, Marseille, France.
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