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Holloway KD, Amisha F, Post G, Goraya H. Hairy Cell Leukemia (HCL) Presenting As Severe Acute Respiratory Distress Syndrome (ARDS) With Legionella pneumophila: Coincidence or Causation? Cureus 2023; 15:e48317. [PMID: 38058334 PMCID: PMC10697807 DOI: 10.7759/cureus.48317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/05/2023] [Indexed: 12/08/2023] Open
Abstract
Due to a low index of suspicion coupled with specific growth conditions and non-specific clinical manifestations, Legionella (L.) pneumophila is a frequently misdiagnosed cause of pneumonia in immunocompromised patients, especially those with hematological malignancies. We present a case of severe acute respiratory distress syndrome (ARDS) secondary to Legionnaire's disease in a patient with newly diagnosed hairy cell leukemia (HCL) to highlight the importance of early recognition, diagnosis, and treatment of Legionnaire's disease to reduce morbidity and mortality.
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Affiliation(s)
- Kayln D Holloway
- Internal Medicine, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Fnu Amisha
- Internal Medicine, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Ginell Post
- Pathology, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Harmeen Goraya
- Internal Medicine - Pulmonology/Critical Care, University of Arkansas for Medical Sciences, Little Rock, USA
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2
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Kim MJ, Moon EK, Jo HJ, Quan FS, Kong HH. Identifying the function of genes involved in excreted vesicle formation in Acanthamoeba castellanii containing Legionella pneumophila. Parasit Vectors 2023; 16:215. [PMID: 37380986 DOI: 10.1186/s13071-023-05824-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 05/28/2023] [Indexed: 06/30/2023] Open
Abstract
BACKGROUND Legionella spp. can survive and replicate inside host cells such as protozoa and macrophages. After enough growth, Legionella is released from the host cells as free legionellae or Legionella-filled vesicles. The vesicles support Legionella to survive for a long time in the environment and transmit to a new host. In this study, we identified the differentially expressed genes of Acanthamoeba infected by Legionella (ACA1_114460, ACA1_091500, and ACA1_362260) and examined their roles in the formation of the excreted vesicles and escape of Legionella from the Acanthamoeba. METHODS After ingestion of Escherichia coli and Legionella pneumophila, expression levels of target genes in Acanthamoeba were measured by real-time polymerase chain reaction (PCR) analysis. The roles of target genes were investigated by transfection of small interfering RNA (siRNA). The formation of Legionella-containing excreted vesicles and the vesicular co-localization with the lysosomes were examined by Giemsa stain and LysoTracker stain. RESULTS ACA1_114460, ACA1_091500, and ACA1_362260 were upregulated after ingestion of Legionella in Acanthamoeba. ACA1_114460- and ACA1_091500-silenced Acanthamoeba failed to form the Legionella-containing excreted vesicles. Legionella was released as free legionellae from the Acanthamoeba. When the ACA1_362260 of Acanthamoeba was silenced, Legionella-containing excreted vesicles were fused with the lysosome. CONCLUSIONS These results indicated that ACA1_114460, ACA1_091500, and ACA1_362260 of Acanthamoeba played important roles in the formation of Legionella-containing excreted vesicles and inhibition of the lysosomal co-localization with the phagosome.
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Affiliation(s)
- Min-Jeong Kim
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - Eun-Kyung Moon
- Department of Medical Zoology, Kyung Hee University School of Medicine, Seoul, Republic of Korea
| | - Hye-Jeong Jo
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - Fu-Shi Quan
- Department of Medical Zoology, Kyung Hee University School of Medicine, Seoul, Republic of Korea
- Medical Research Center for Bioreaction to Reactive Oxygen Species and Biomedical Science Institute, School of Medicine, Graduate school, Kyung Hee University, Seoul, Republic of Korea
| | - Hyun-Hee Kong
- Department of Parasitology, Dong-A University College of Medicine, Busan, Republic of Korea.
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3
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Shames SR. Eat or Be Eaten: Strategies Used by Legionella to Acquire Host-Derived Nutrients and Evade Lysosomal Degradation. Infect Immun 2023; 91:e0044122. [PMID: 36912646 PMCID: PMC10112212 DOI: 10.1128/iai.00441-22] [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] [Indexed: 03/14/2023] Open
Abstract
To replicate within host cells, bacterial pathogens must acquire host-derived nutrients while avoiding degradative antimicrobial pathways. Fundamental insights into bacterial pathogenicity have been revealed by bacteria of the genus Legionella, which naturally parasitize free-living protozoa by establishing a membrane-bound replicative niche termed the Legionella-containing vacuole (LCV). Biogenesis of the LCV and intracellular replication rely on rapid evasion of the endocytic pathway and acquisition of host-derived nutrients, much of which is mediated by bacterial effector proteins translocated into host cells by a Dot/Icm type IV secretion system. Billions of years of co-evolution with eukaryotic hosts and broad host tropism have resulted in expansion of the Legionella genome to accommodate a massive repertoire of effector proteins that promote LCV biogenesis, safeguard the LCV from endolysosomal maturation, and mediate the acquisition of host nutrients. This minireview is focused on the mechanisms by which an ancient intracellular pathogen leverages effector proteins and hijacks host cell biology to obtain essential host-derived nutrients and prevent lysosomal degradation.
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Affiliation(s)
- Stephanie R. Shames
- Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
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Mai Y, Zheng J, Zeng J, Wang Z, Liu F, Ma L, Zhou M, Zhao S, Wu B, Wang C, Yan Q, He Z, Shu L. Protozoa as Hotspots for Potential Pathogens in the Drinking Water of a Subtropical Megacity: Diversity, Treatment, and Health Risk. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:6108-6118. [PMID: 37026396 DOI: 10.1021/acs.est.2c09139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Drinking water systems host a wide range of microorganisms essential for biosafety. However, one major group of waterborne pathogens, protozoa, is relatively neglected compared to bacteria and other microorganisms. Until now, little is known about the growth and fate of protozoa and their associated bacteria in drinking water systems. In this study, we aim to investigate how drinking water treatment affects the growth and fate of protozoa and their associated bacteria in a subtropical megacity. The results showed that viable protozoa were prevalent in the city's tap water, and amoebae were the major component of tap water protozoa. In addition, protozoan-associated bacteria contained many potential pathogens and were primarily enriched in amoeba hosts. Furthermore, this study showed that current drinking water disinfection methods have little effect on protozoa and their associated bacteria. Besides, ultrafiltration membranes unexpectedly served as an ideal growth surface for amoebae in drinking water systems, and they could significantly promote the growth of amoeba-associated bacteria. In conclusion, this study shows that viable protozoa and their associated bacteria are prevalent in tap water, which may present an emerging health risk in drinking water biosafety.
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Affiliation(s)
- Yingwen Mai
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Jianyi Zheng
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Jiaxiong Zeng
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Zihe Wang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Fei Liu
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Lu Ma
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Min Zhou
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Shanshan Zhao
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Bo Wu
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Cheng Wang
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Qingyun Yan
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Zhili He
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
| | - Longfei Shu
- Environmental Microbiomics Research Center, School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510006, China
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Scheithauer L, Karagöz MS, Mayer BE, Steinert M. Protein sociology of ProA, Mip and other secreted virulence factors at the Legionella pneumophila surface. Front Cell Infect Microbiol 2023; 13:1140688. [PMID: 36936764 PMCID: PMC10017501 DOI: 10.3389/fcimb.2023.1140688] [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: 01/09/2023] [Accepted: 02/17/2023] [Indexed: 03/06/2023] Open
Abstract
The pathogenicity of L. pneumophila, the causative agent of Legionnaires' disease, depends on an arsenal of interacting proteins. Here we describe how surface-associated and secreted virulence factors of this pathogen interact with each other or target extra- and intracellular host proteins resulting in host cell manipulation and tissue colonization. Since progress of computational methods like AlphaFold, molecular dynamics simulation, and docking allows to predict, analyze and evaluate experimental proteomic and interactomic data, we describe how the combination of these approaches generated new insights into the multifaceted "protein sociology" of the zinc metalloprotease ProA and the peptidyl-prolyl cis/trans isomerase Mip (macrophage infectivity potentiator). Both virulence factors of L. pneumophila interact with numerous proteins including bacterial flagellin (FlaA) and host collagen, and play important roles in virulence regulation, host tissue degradation and immune evasion. The recent progress in protein-ligand analyses of virulence factors suggests that machine learning will also have a beneficial impact in early stages of drug discovery.
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Affiliation(s)
- Lina Scheithauer
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Mustafa Safa Karagöz
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Benjamin E. Mayer
- Computational Biology & Simulation, Technische Universität Darmstadt, Darmstadt, Germany
| | - Michael Steinert
- Institut für Mikrobiologie, Technische Universität Braunschweig, Braunschweig, Germany
- *Correspondence: Michael Steinert,
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6
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Idowu M, Taiwo G, Sidney T, Morenikeji OB, Pech Cervantes A, Estrada-Reyes ZM, Wilson M, Ogunade IM. The differential plasma and ruminal metabolic pathways and ruminal bacterial taxa associated with divergent residual body weight gain phenotype in crossbred beef steers. Transl Anim Sci 2023; 7:txad054. [PMID: 37435477 PMCID: PMC10332501 DOI: 10.1093/tas/txad054] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 05/18/2023] [Indexed: 07/13/2023] Open
Abstract
We applied ruminal and plasma metabolomics and ruminal 16S rRNA gene sequencing to determine the metabolic pathways and ruminal bacterial taxa associated with divergent residual body weight gain phenotype in crossbred beef steers. A group of 108 crossbred growing beef steers (average BW = 282.87 ± 30 kg) were fed a forage-based diet for a period of 56 d in a confinement dry lot equipped with GrowSafe intake nodes to determine their residual body weight gain (RADG) phenotype. After RADG identification, blood and rumen fluid samples were collected from beef steers with the highest RADG (most efficient; n = 16; 0.76 kg/d) and lowest RADG (least efficient; n = 16; -0.65 kg/d). Quantitative untargeted metabolome analysis of the plasma and rumen fluid samples were conducted using chemical isotope labelling/liquid chromatography-mass spectrometry. Differentially abundant metabolites in each of the plasma and rumen fluid samples between the two groups of beef steers were determined using a false discovery rate (FDR)-adjusted P-values ≤ 0.05 and area under the curve (AUC) > 0.80. Rumen and plasma metabolic pathways that were differentially enriched or depleted (P ≤ 0.05) in beef steers with positive RADG compared to those with negative RADG were determined by the quantitative pathway enrichment analysis. A total of 1,629 metabolites were detected and identified in the plasma of the beef steers; eight metabolites including alanyl-phenylalanine, 8-hydroxyguanosine, and slaframine were differentially abundant (FDR ≤ 0.05; AUC > 0.80) in beef steers with divergent RADG; five metabolic pathways including steroid hormone biosynthesis, thiamine metabolism, propanoate metabolism, pentose phosphate pathway, and butanoate metabolism were enriched (P ≤ 0.05) in beef steers with positive RADG, relative to negative RADG steers. A total of 1,908 metabolites were detected and identified in the rumen of the beef steers; results of the pathway enrichment analysis of all the metabolites revealed no metabolic pathways in the rumen were altered (P > 0.05). The rumen fluid samples were also analyzed using 16S rRNA gene sequencing to assess the bacterial community composition. We compared the rumen bacterial community composition at the genus level using a linear discriminant analysis effect size (LEfSe) to identify the differentially abundant taxa between the two groups of beef steers. The LEfSe results showed greater relative abundance of Bacteroidetes_vadinHA17 and Anaerovibrio in steers with positive RADG compared to the negative RADG group, while steers in the negative RADG group had greater relative abundance of Candidatus_Amoebophilus, Clostridium_sensu_stricto_1, Pseudomonas, Empedobacter, Enterobacter, and Klebsiella compared to the positive RADG group. Our results demonstrate that beef steers with positive or negative RADG exhibit differences in plasma metabolic profiles and some ruminal bacterial taxa which probably explain their divergent feed efficiency phenotypes.
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Affiliation(s)
- Modoluwamu Idowu
- Division of Animal Science and Nutritional Science, West Virginia University, Morgantown, WV 26505, USA
| | - Godstime Taiwo
- Division of Animal Science and Nutritional Science, West Virginia University, Morgantown, WV 26505, USA
| | - Taylor Sidney
- Division of Animal Science and Nutritional Science, West Virginia University, Morgantown, WV 26505, USA
| | - Olanrewaju B Morenikeji
- Division of Biological and Health Sciences, University of Pittsburgh, Bradford, PA 16701, USA
| | | | - Zaira M Estrada-Reyes
- North Carolina Agricultural and Technical State University, Greensboro, NC 27411, USA
| | - Matthew Wilson
- Division of Animal Science and Nutritional Science, West Virginia University, Morgantown, WV 26505, USA
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7
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Yang JL, Li D, Zhan XY. Concept about the Virulence Factor of Legionella. Microorganisms 2022; 11:microorganisms11010074. [PMID: 36677366 PMCID: PMC9867486 DOI: 10.3390/microorganisms11010074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/23/2022] [Accepted: 12/23/2022] [Indexed: 12/29/2022] Open
Abstract
Pathogenic species of Legionella can infect human alveolar macrophages through Legionella-containing aerosols to cause a disease called Legionellosis, which has two forms: a flu-like Pontiac fever and severe pneumonia named Legionnaires' disease (LD). Legionella is an opportunistic pathogen that frequently presents in aquatic environments as a biofilm or protozoa parasite. Long-term interaction and extensive co-evolution with various genera of amoebae render Legionellae pathogenic to infect humans and also generate virulence differentiation and heterogeneity. Conventionally, the proteins involved in initiating replication processes and human macrophage infections have been regarded as virulence factors and linked to pathogenicity. However, because some of the virulence factors are associated with the infection of protozoa and macrophages, it would be more accurate to classify them as survival factors rather than virulence factors. Given that the molecular basis of virulence variations among non-pathogenic, pathogenic, and highly pathogenic Legionella has not yet been elaborated from the perspective of virulence factors, a comprehensive explanation of how Legionella infects its natural hosts, protozoans, and accidental hosts, humans is essential to show a novel concept regarding the virulence factor of Legionella. In this review, we overviewed the pathogenic development of Legionella from protozoa, the function of conventional virulence factors in the infections of protozoa and macrophages, the host's innate immune system, and factors involved in regulating the host immune response, before discussing a probably new definition for the virulence factors of Legionella.
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Terpinen-4-ol, the Main Bioactive Component of Tea Tree Oil, as an Innovative Antimicrobial Agent against Legionella pneumophila. Pathogens 2022; 11:pathogens11060682. [PMID: 35745536 PMCID: PMC9229490 DOI: 10.3390/pathogens11060682] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/08/2022] [Accepted: 06/10/2022] [Indexed: 12/04/2022] Open
Abstract
Legionella pneumophila (Lp), responsible for a severe pneumonia called Legionnaires’ disease, represents an important health burden in Europe. Prevention and control of Lp contamination in warm water systems is still a great challenge often due to the failure in disinfection procedures. The aim of this study was to evaluate the in vitro activity of Terpinen-4-ol (T-4-ol) as potential agent for Lp control, in comparison with the essential oil of Melaleuca alternifolia (tea tree) (TTO. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of T-4-ol were determined by broth micro-dilution and a micro-atmosphere diffusion method to investigate the anti-Lp effects of T-4-ol and TTO vapors. Scanning Electron Microscopy (SEM) was adopted to highlight the morphological changes and Lp damage following T-4-ol and TTO treatments. The greatest antimicrobial activity against Lp was shown by T-4-ol with a MIC range of 0.06–0.125% v/v and MBC range of 0.25–0.5% v/v. The TTO and T-4-ol MIC and MBC decreased with increasing temperature (36 °C to 45 ± 1 °C), and temperature also significantly influenced the efficacy of TTO and T-4-ol vapors. The time-killing assay showed an exponential trend of T-4-ol bactericidal activity at 0.5% v/v against Lp. SEM observations revealed a concentration- and temperature- dependent effect of T-4-ol and TTO on cell surface morphology with alterations. These findings suggest that T-4-ol is active against Lp and further studies may address the potential effectiveness of T-4-ol for control of water systems.
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Tropheryma whipplei, Helicobacter pylori, and Intestinal Protozoal Co-Infections in Italian and Immigrant Populations: A Cross-Sectional Study. Microorganisms 2022; 10:microorganisms10040769. [PMID: 35456819 PMCID: PMC9027763 DOI: 10.3390/microorganisms10040769] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 03/31/2022] [Accepted: 04/01/2022] [Indexed: 12/28/2022] Open
Abstract
Tropheryma whipplei (TW), Helicobacter pylori (HP), and intestinal protozoa (IP) are widespread pathogens with similar routes of transmission and epidemiological risk factors. Epidemiological data on co-infection between TW, HP, and IP are scarce. We aim to more deeply investigate the co-infection rate for these pathogens, evaluating the risk factors and symptoms. Methods: This is a cross-sectional study conducted at the IRCCS Sacro Cuore Don Calabria Hospital in Northern Italy, a referral center for tropical and Whipple’s disease (WD). Stored stool samples from 143 subjects previously tested for TW DNA by real-time PCR were explored for HP and IP DNA detection. The virulence factor cagA was investigated in HP-positive patients. Results: A history of migration was reported significantly more in TW-positive than in negative subjects (34.1% vs. 9.1%, p = 0.001) and in HP-infected than in those non-infected (59.1% vs. 9.1%, p < 0.001). The HP infection rate differed significantly between TW-infected and uninfected groups (31.8% vs. 8.1%, p = 0.001), while no difference was observed for IP infection. Significantly higher TW intestinal colonization was found in HP-infected patients than in non-infected (63.6% vs. 24.8%, p < 0.001). In addition, the proportion of Blastocysts positive finding was also significantly higher in HP-infected than in non-infected (40.9% vs. 17.4%, p = 0.018). Conclusions: The present study is the first to report a high TW and HP co-infection rate. To reduce the risk of morbidity from a chronic infection of either pathogen, clinicians may consider TW-HP molecular screening on the same stool sample for patients with suspected HP disease or WD, particularly in case of travel history.
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Du J, Ma B, Li J, Wang Y, Dou T, Xu S, Zhang M. Rapid Detection and Differentiation of Legionella pneumophila and Non-Legionella pneumophila Species by Using Recombinase Polymerase Amplification Combined With EuNPs-Based Lateral Flow Immunochromatography. Front Chem 2022; 9:815189. [PMID: 35198541 PMCID: PMC8859533 DOI: 10.3389/fchem.2021.815189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 12/28/2021] [Indexed: 11/13/2022] Open
Abstract
Legionella, a waterborne pathogen, is the main cause of Legionnaires’ disease. Therefore, timely and accurate detection and differentiation of Legionella pneumophila and non-Legionella pneumophila species is crucial. In this study, we develop an easy and rapid recombinase polymerase amplification assay combined with EuNPs-based lateral flow immunochromatography (EuNPs-LFIC-RPA) to specifically distinguish Legionella pneumophila and non-Legionella pneumophila. We designed primers based on the mip gene of Legionella pneumophila and the 5S rRNA gene of non-Legionella pneumophila. The recombinase polymerase amplification reaction could go to completion in 10 min at 37°C, and the amplification products could be detected within 5 min with EuNPs-LFIC strips. Using a florescent test strip reader, the quantitative results were achieved by reading the colored signal intensities on the strips. The sensitivity was 1.6 × 101 CFU/ml, and a linear standard linear curve plotted from the test strip reader had a correlation coefficient for the determination of Legionella pneumophila (R2 = 0.9516). Completed concordance for the presence or absence of Legionella pneumophila by EuNPs-LFIC-RPA and qPCR was 97.32% (κ = 0.79, 95% CI), according to an analysis of practical water samples (n = 112). In short, this work shows the feasibility of EuNPs-LFIC-RPA for efficient and rapid monitoring of Legionella pneumophila and non-Legionella pneumophila in water samples.
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11
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Vaughn B, Abu Kwaik Y. Idiosyncratic Biogenesis of Intracellular Pathogens-Containing Vacuoles. Front Cell Infect Microbiol 2021; 11:722433. [PMID: 34858868 PMCID: PMC8632064 DOI: 10.3389/fcimb.2021.722433] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 10/25/2021] [Indexed: 12/12/2022] Open
Abstract
While most bacterial species taken up by macrophages are degraded through processing of the bacteria-containing vacuole through the endosomal-lysosomal degradation pathway, intravacuolar pathogens have evolved to evade degradation through the endosomal-lysosomal pathway. All intra-vacuolar pathogens possess specialized secretion systems (T3SS-T7SS) that inject effector proteins into the host cell cytosol to modulate myriad of host cell processes and remodel their vacuoles into proliferative niches. Although intravacuolar pathogens utilize similar secretion systems to interfere with their vacuole biogenesis, each pathogen has evolved a unique toolbox of protein effectors injected into the host cell to interact with, and modulate, distinct host cell targets. Thus, intravacuolar pathogens have evolved clear idiosyncrasies in their interference with their vacuole biogenesis to generate a unique intravacuolar niche suitable for their own proliferation. While there has been a quantum leap in our knowledge of modulation of phagosome biogenesis by intravacuolar pathogens, the detailed biochemical and cellular processes affected remain to be deciphered. Here we discuss how the intravacuolar bacterial pathogens Salmonella, Chlamydia, Mycobacteria, Legionella, Brucella, Coxiella, and Anaplasma utilize their unique set of effectors injected into the host cell to interfere with endocytic, exocytic, and ER-to-Golgi vesicle traffic. However, Coxiella is the main exception for a bacterial pathogen that proliferates within the hydrolytic lysosomal compartment, but its T4SS is essential for adaptation and proliferation within the lysosomal-like vacuole.
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Affiliation(s)
- Bethany Vaughn
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY, United States
| | - Yousef Abu Kwaik
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY, United States.,Center for Predictive Medicine, College of Medicine, University of Louisville, Louisville, KY, United States
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12
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Logan-Jackson A, Rose JB. Cooccurrence of Five Pathogenic Legionella spp. and Two Free-Living Amoebae Species in a Complete Drinking Water System and Cooling Towers. Pathogens 2021; 10:pathogens10111407. [PMID: 34832563 PMCID: PMC8619718 DOI: 10.3390/pathogens10111407] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/25/2021] [Accepted: 10/28/2021] [Indexed: 12/13/2022] Open
Abstract
Pathogenic Legionella species grow optimally inside free-living amoebae to concentrations that increase risks to those who are exposed. The aim of this study was to screen a complete drinking water system and cooling towers for the occurrence of Acanthamoeba spp. and Naegleria fowleri and their cooccurrence with Legionella pneumophila, Legionella anisa, Legionella micdadei, Legionella bozemanii, and Legionella longbeachae. A total of 42 large-volume water samples, including 12 from the reservoir (water source), 24 from two buildings (influents to the buildings and exposure sites (taps)), and six cooling towers were collected and analyzed using droplet digital PCR (ddPCR). N. fowleri cooccurred with L. micdadei in 76 (32/42) of the water samples. In the building water system, the concentrations of N. fowleri and L. micdadei ranged from 1.5 to 1.6 Log10 gene copies (GC)/100 mL, but the concentrations of species increased in the cooling towers. The data obtained in this study illustrate the ecology of pathogenic Legionella species in taps and cooling towers. Investigating Legionella’s ecology in drinking and industrial waters will hopefully lead to better control of these pathogenic species in drinking water supply systems and cooling towers.
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Affiliation(s)
- Alshae Logan-Jackson
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
- Correspondence:
| | - Joan B. Rose
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI 48824, USA;
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Croze A, Carlino A, Quélard B, Saha A, Convert T, Eberst JB, Demanèche S. Intracellular Behaviour of Legionella Non- pneumophila Strains within Three Amoeba Strains, Including Willaertia magna C2c Maky. Pathogens 2021; 10:pathogens10101350. [PMID: 34684299 PMCID: PMC8538512 DOI: 10.3390/pathogens10101350] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/07/2021] [Accepted: 10/15/2021] [Indexed: 01/05/2023] Open
Abstract
Legionellosis, an often-lethal pneumonia, is generally associated with contamination by Legionella pneumophila. This bacterium can persist in the environment and resist chemical treatment when it is internalized by amoebae. In addition, there is increasing medical proof that other Legionella species can be causative agents of Legionellosis. The objective of this study was to evaluate whether Legionella non-pneumophila (Lnp) strains were able to use the machinery of amoeba to multiply, or whether amoebae were able to limit their proliferation. Seven strains belonging to the species L. longbeachae, L. anisa, L. bozemanae, L. taurinensis, and L. dumoffii were cocultured with three amoebae, Acanthamoeba castellanii, Willaertia magna T5(S)44, and Willaertia magna C2c Maky, at two temperatures, 22 and 37 °C. We found that at 22 °C, all amoebae were able to phagocytose the seven Lnp strains and to avoid intracellular development, except for L. longbeachae, which was able to multiply inside W. magna T5(S)44. At 37 °C, four Lnp strains were able to hijack the machinery of one or two amoebae and to use it to proliferate, but none were able to multiply inside W. magna C2c Maky.
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Zhan XY, Yang JL, Zhou X, Qian YC, Huang K, Sun H, Wang H, Leng Y, Huang B, He Y. Virulence effector SidJ evolution in Legionella pneumophila is driven by positive selection and intragenic recombination. PeerJ 2021; 9:e12000. [PMID: 34458026 PMCID: PMC8378335 DOI: 10.7717/peerj.12000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 07/27/2021] [Indexed: 11/20/2022] Open
Abstract
Effector proteins translocated by the Dot/Icm type IV secretion system determine the virulence of Legionella pneumophila (L. pneumophila). Among these effectors, members of the SidE family (SidEs) regulate several cellular processes through a unique phosphoribosyl ubiquitination mechanism mediated by another effector, SidJ. Host-cell calmodulin (CaM) activates SidJ to glutamylate the SidEs of ubiquitin (Ub) ligases and to make a balanced Ub ligase activity. Given the central role of SidJ in this regulatory process, studying the nature of evolution of sidJ is important to understand the virulence of L. pneumophila and the interaction between the bacteria and its hosts. By studying sidJ from a large number of L. pneumophila strains and using various molecular evolution algorithms, we demonstrated that intragenic recombination drove the evolution of sidJ and contributed to sidJ diversification. Additionally, we showed that four codons of sidJ which are located in the N-terminal (NTD) (codons 58 and 200) and C-terminal (CTD) (codons 868 and 869) domains, but not in the kinase domain (KD) had been subjected to strong positive selection pressure, and variable mutation profiles of these codons were identified. Protein structural modeling of SidJ provided possible explanations for these mutations. Codons 868 and 869 mutations might engage in regulating the interactions of SidJ with CaM through hydrogen bonds and affect the CaM docking to SidJ. Mutation in codon 58 of SidJ might affect the distribution of main-chain atoms that are associated with the interaction with CaM. In contrast, mutations in codon 200 might influence the α-helix stability in the NTD. These mutations might be important to balance Ub ligase activity for different L. pneumophila hosts. This study first reported that intragenic recombination and positive Darwinian selection both shaped the genetic plasticity of sidJ, contributing to a deeper understanding of the adaptive mechanisms of this intracellular bacterium to different hosts.
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Affiliation(s)
- Xiao-Yong Zhan
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Jin-Lei Yang
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Xuefu Zhou
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Yi-Chao Qian
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Ke Huang
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Honghua Sun
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Huacheng Wang
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Yang Leng
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Bihui Huang
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
| | - Yulong He
- The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China
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War of the microbial world: Acanthamoeba spp. interactions with microorganisms. Folia Microbiol (Praha) 2021; 66:689-699. [PMID: 34145552 PMCID: PMC8212903 DOI: 10.1007/s12223-021-00889-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 06/09/2021] [Indexed: 12/15/2022]
Abstract
Acanthamoeba is known to interact with a plethora of microorganisms such as bacteria, fungi and viruses. In these interactions, the amoebae can be predatory in nature, transmission vehicle or an incubator. Amoebae consume microorganisms, especially bacteria, as food source to fulfil their nutritional needs by taking up bacteria through phagocytosis and lysing them in phagolysosomes and hence play an eminent role in the regulation of bacterial density in the nature and accountable for eradication of around 60% of the bacterial population in the environment. Acanthamoeba can also act as a “Trojan horse” for microbial transmission in the environment. Additionally, Acanthamoeba may serve as an incubator-like reservoir for microorganisms, including those that are pathogenic to humans, where the microorganisms use amoebae’s defences to resist harsh environment and evade host defences and drugs, whilst growing in numbers inside the amoebae. Furthermore, amoebae can also be used as a “genetic melting pot” where exchange of genes as well as adaptation of microorganisms, leading to higher pathogenicity, may arise. Here, we describe bacteria, fungi and viruses that are known to interact with Acanthamoeba spp.
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Rayamajhee B, Subedi D, Peguda HK, Willcox MD, Henriquez FL, Carnt N. A Systematic Review of Intracellular Microorganisms within Acanthamoeba to Understand Potential Impact for Infection. Pathogens 2021; 10:pathogens10020225. [PMID: 33670718 PMCID: PMC7922382 DOI: 10.3390/pathogens10020225] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/13/2021] [Accepted: 02/15/2021] [Indexed: 12/20/2022] Open
Abstract
Acanthamoeba, an opportunistic pathogen is known to cause an infection of the cornea, central nervous system, and skin. Acanthamoeba feeds different microorganisms, including potentially pathogenic prokaryotes; some of microbes have developed ways of surviving intracellularly and this may mean that Acanthamoeba acts as incubator of important pathogens. A systematic review of the literature was performed in order to capture a comprehensive picture of the variety of microbial species identified within Acanthamoeba following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Forty-three studies met the inclusion criteria, 26 studies (60.5%) examined environmental samples, eight (18.6%) studies examined clinical specimens, and another nine (20.9%) studies analysed both types of samples. Polymerase chain reaction (PCR) followed by gene sequencing was the most common technique used to identify the intracellular microorganisms. Important pathogenic bacteria, such as E. coli, Mycobacterium spp. and P. aeruginosa, were observed in clinical isolates of Acanthamoeba, whereas Legionella, adenovirus, mimivirus, and unidentified bacteria (Candidatus) were often identified in environmental Acanthamoeba. Increasing resistance of Acanthamoeba associated intracellular pathogens to antimicrobials is an increased risk to public health. Molecular-based future studies are needed in order to assess the microbiome residing in Acanthamoeba, as a research on the hypotheses that intracellular microbes can affect the pathogenicity of Acanthamoeba infections.
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Affiliation(s)
- Binod Rayamajhee
- School of Optometry and Vision Science, University of New South Wales (UNSW), Sydney, NSW 2052, Australia; (H.K.P.); (M.D.W.); (N.C.)
- Department of Infection and Immunology, Kathmandu Research Institute for Biological Sciences (KRIBS), Lalitpur 44700, Nepal
- Correspondence: or
| | - Dinesh Subedi
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia;
| | - Hari Kumar Peguda
- School of Optometry and Vision Science, University of New South Wales (UNSW), Sydney, NSW 2052, Australia; (H.K.P.); (M.D.W.); (N.C.)
| | - Mark Duncan Willcox
- School of Optometry and Vision Science, University of New South Wales (UNSW), Sydney, NSW 2052, Australia; (H.K.P.); (M.D.W.); (N.C.)
| | - Fiona L. Henriquez
- Institute of Biomedical and Environmental Health Research, School of Health and Life Sciences, University of the West of Scotland (UWS), Paisley PA1 2BE, UK;
| | - Nicole Carnt
- School of Optometry and Vision Science, University of New South Wales (UNSW), Sydney, NSW 2052, Australia; (H.K.P.); (M.D.W.); (N.C.)
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Ngwaga T, Chauhan D, Shames SR. Mechanisms of Effector-Mediated Immunity Revealed by the Accidental Human Pathogen Legionella pneumophila. Front Cell Infect Microbiol 2021; 10:593823. [PMID: 33614523 PMCID: PMC7886983 DOI: 10.3389/fcimb.2020.593823] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 12/22/2020] [Indexed: 12/25/2022] Open
Abstract
Many Gram-negative bacterial pathogens employ translocated virulence factors, termed effector proteins, to facilitate their parasitism of host cells and evade host anti-microbial defenses. However, eukaryotes have evolved to detect effector-mediated virulence strategies through a phenomenon termed effector-triggered immunity (ETI). Although ETI was discovered in plants, a growing body of literature demonstrates that metazoans also utilize effector-mediated immunity to detect and clear bacterial pathogens. This mini review is focused on mechanisms of effector-mediated immune responses by the accidental human pathogen Legionella pneumophila. We highlight recent advancements in the field and discuss the future prospects of harnessing effectors for the development of novel therapeutics, a critical need due to the prevalence and rapid spread of antibiotic resistance.
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Affiliation(s)
- Tshegofatso Ngwaga
- Division of Biology, Kansas State University, Manhattan, KS, United States
| | - Deepika Chauhan
- Division of Biology, Kansas State University, Manhattan, KS, United States
| | - Stephanie R Shames
- Division of Biology, Kansas State University, Manhattan, KS, United States
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18
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Saad M, Chinerman D, Tabrizian M, Faucher SP. Identification of two aptamers binding to Legionella pneumophila with high affinity and specificity. Sci Rep 2020; 10:9145. [PMID: 32499557 PMCID: PMC7272621 DOI: 10.1038/s41598-020-65973-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 05/13/2020] [Indexed: 12/21/2022] Open
Abstract
Legionella pneumophila (Lp) is a water borne bacterium causing Legionnaires’ Disease (LD) in humans. Rapid detection of Lp in water system is essential to reduce the risk of LD outbreaks. The methods currently available require expert skills and are time intensive, thus delaying intervention. In situ detection of Lp by biosensor would allow rapid implementation of control strategies. To this end, a biorecognition element is required. Aptamers are considered promising biorecognition molecules for biosensing. Aptamers are short oligonucleotide sequence folding into a specific structure and are able to bind to specific molecules. Currently, no aptamer and thus no aptamer-based technology exists for the detection of Lp. In this study, Systemic Evolution of Ligands through EXponential enrichment (SELEX) was used to identify aptamers binding specifically to Lp. Ten rounds of positive selection and two rounds of counter-selection against two Pseudomonas species were performed. Two aptamers binding strongly to Lp were identified with KD of 116 and 135 nM. Binding specificity of these two aptamers to Lp was confirmed by flow cytometry and fluorescence microscopy. Therefore, these two aptamers are promising biorecognition molecules for the detection of Lp in water systems.
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Affiliation(s)
- Mariam Saad
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, Ste-Anne-de-Bellevue, Quebec, H9X 3V9, Canada.,Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Université de Montréal, Faculté de Médecine Vétérinaire, Saint-Hyacinthe, Québec, J2S 2M2, Canada
| | - Deanna Chinerman
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, Ste-Anne-de-Bellevue, Quebec, H9X 3V9, Canada
| | - Maryam Tabrizian
- Department of Biomedical Engineering, Faculty of Medicine, McGill University, Montreal, Quebec, H3A 2B4, Canada.,Faculty of Dentistry, McGill University, Montreal, Quebec, H3A 2B4, Canada
| | - Sebastien P Faucher
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, Ste-Anne-de-Bellevue, Quebec, H9X 3V9, Canada. .,Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Université de Montréal, Faculté de Médecine Vétérinaire, Saint-Hyacinthe, Québec, J2S 2M2, Canada.
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20
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Ma L, Li B, Zhang T. New insights into antibiotic resistome in drinking water and management perspectives: A metagenomic based study of small-sized microbes. WATER RESEARCH 2019; 152:191-201. [PMID: 30669041 DOI: 10.1016/j.watres.2018.12.069] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 12/18/2018] [Accepted: 12/22/2018] [Indexed: 05/21/2023]
Abstract
The proliferation of antibiotic resistance genes (ARGs) in drinking water and their potential horizontal transfer to pathogenic microbes may cause failure of antibiotics. However, antimicrobial resistome monitoring in drinking water is not currently routine. The bacterial hosts of ARGs, especially small-sized microbes in drinking water, may not be effectively removed by membrane filtration disinfection and thus pose threats to human health. In the present study, using metagenomic based approach, we investigated antibiotic resistome of small-sized microbes (0.2-0.45 μm) in 20 household drinking water samples from 12 cities in Mainland China, Hong Kong and Singapore. A total of 265 ARG subtypes belonging to 17 ARG types were detected at abundances ranging from 4.0 × 10-2 to 1.0 × 100 copies/cell. Multidrug, bacitracin and aminoglycoside resistance genes are dominant, and 43 ARG subtypes were specifically carried by small-size microbes. Metagenomic assembly strategy revealed fragments of three opportunistic pathogen, i.e. Pseudomonas alcaligenes, Pseudomonas aeruginosa and Mycobacterium gordonae, carried mexW, aph(3')-I and aac(2')-I, respectively. Drinking water samples were classified into three groups based on the presence of ARG, pathogen and ARG-carrying pathogen. These new insights into the antibiotic resistome of small microbes in drinking water over a broad scale indicate the need for more comprehensive ARGs monitoring and surveillance of drinking water supplies. These findings, together with the perspectives and strategies proposed in this study, could support initiatives to improve drinking water safety.
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Affiliation(s)
- Liping Ma
- Environmental Biotechnology Laboratory, The University of Hong Kong, Hong Kong, China; Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China
| | - Bing Li
- Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Graduate School at Shenzhen, Tsinghua University, China
| | - Tong Zhang
- Environmental Biotechnology Laboratory, The University of Hong Kong, Hong Kong, China; School of Public Health, The University of Hong Kong, Hong Kong, China; International Center for Antibiotic Resistance in the Environment, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China.
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21
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Beltrame A, Ragusa A, Perandin F, Formenti F, Fenollar F, Edouard S, Laroche M, Zavarise G, Doro F, Giorli G, Raoult D, Bisoffi Z. Tropheryma whipplei intestinal colonization in Italian and migrant population: a retrospective observational study. Future Microbiol 2019; 14:283-292. [PMID: 30855186 DOI: 10.2217/fmb-2018-0347] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM To obtain the first molecular epidemiological survey of Tropheryma whipplei intestinal colonization in Italy. Materials & methods: Retrospective, observational study to assess the prevalence of T. whipplei, the causative agent of Whipple's disease, in stool samples (real-time PCR) of patients attending the Center for Tropical Diseases (Italy) and risk factors associated. RESULTS Overall prevalence was 6.9% (85/1240). The younger age group showed a significantly higher rate than older age group (12.7 vs 5.9%, p = 0.002). The prevalence was 4.9% for Italians and 9.3% for migrants (p = 0.003). Among the latter, children less than 10 years had higher prevalence than older ones (17.3 vs 7.3%, p = 0.003). The young age, male gender and Giardia duodenalis and Entamoeba histolytica coinfection were risk factors. CONCLUSION Our study confirms an increased risk of acquiring T. whipplei infection during childhood, under poor sanitary conditions.
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Affiliation(s)
- Anna Beltrame
- Centre for Tropical Diseases, IRCCS Sacro Cuore - Don Calabria Hospital, Via Sempreboni 5, 37024 Negrar, Italy
| | - Andrea Ragusa
- Centre for Tropical Diseases, IRCCS Sacro Cuore - Don Calabria Hospital, Via Sempreboni 5, 37024 Negrar, Italy
| | - Francesca Perandin
- Centre for Tropical Diseases, IRCCS Sacro Cuore - Don Calabria Hospital, Via Sempreboni 5, 37024 Negrar, Italy
| | - Fabio Formenti
- Centre for Tropical Diseases, IRCCS Sacro Cuore - Don Calabria Hospital, Via Sempreboni 5, 37024 Negrar, Italy
| | - Florence Fenollar
- Aix Marseille Univ, AP-HM, MEPHI, IHU-Méditerranée Infection, 19-21 Bd Jean Moulin, 13005, France
| | - Sophie Edouard
- Aix Marseille Univ, AP-HM, MEPHI, IHU-Méditerranée Infection, 19-21 Bd Jean Moulin, 13005, France
| | - Maureen Laroche
- Aix Marseille Univ, AP-HM, MEPHI, IHU-Méditerranée Infection, 19-21 Bd Jean Moulin, 13005, France
| | - Giorgio Zavarise
- Paediatrics Department, IRCSS Sacro Cuore - Don Calabria Hospital, Via Sempreboni 5, 37024 Negrar, Italy
| | - Francesco Doro
- Paediatrics Department, IRCSS Sacro Cuore - Don Calabria Hospital, Via Sempreboni 5, 37024 Negrar, Italy
| | - Giovanni Giorli
- Centre for Tropical Diseases, IRCCS Sacro Cuore - Don Calabria Hospital, Via Sempreboni 5, 37024 Negrar, Italy
| | - Didier Raoult
- Aix Marseille Univ, AP-HM, MEPHI, IHU-Méditerranée Infection, 19-21 Bd Jean Moulin, 13005, France
| | - Zeno Bisoffi
- Centre for Tropical Diseases, IRCCS Sacro Cuore - Don Calabria Hospital, Via Sempreboni 5, 37024 Negrar, Italy.,Department of Diagnostic & Public Health, University of Verona, P.le L. A. Scuro 10, 37134 Verona, Italy
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Beatson SA, Bartley PB. Diving Deep Into Hospital-Acquired Legionella pneumophila With Whole-Genome Sequencing. Clin Infect Dis 2018; 64:1260-1262. [PMID: 28369254 DOI: 10.1093/cid/cix156] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 02/20/2017] [Indexed: 01/16/2023] Open
Affiliation(s)
- Scott A Beatson
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Paul B Bartley
- School of Medicine, The University of Queensland, Brisbane, Queensland, Australia.,Wesley-St Andrew's Research Institute, Brisbane, Queensland, Australia
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Abstract
Within the human host, Legionella pneumophila replicates within alveolar macrophages, leading to pneumonia. However, L. pneumophila is an aquatic generalist pathogen that replicates within a wide variety of protist hosts, including amoebozoa, percolozoa, and ciliophora. The intracellular lifestyles of L. pneumophila within the two evolutionarily distant hosts macrophages and protists are remarkably similar. Coevolution with numerous protist hosts has shaped plasticity of the genome of L. pneumophila, which harbors numerous proteins encoded by genes acquired from primitive eukaryotic hosts through interkingdom horizontal gene transfer. The Dot/Icm type IVb translocation system translocates ∼6,000 effectors among Legionella species and >320 effector proteins in L. pneumophila into host cells to modulate a plethora of cellular processes to create proliferative niches. Since many of the effectors have likely evolved to modulate cellular processes of primitive eukaryotic hosts, it is not surprising that most of the effectors do not contribute to intracellular growth within human macrophages. Some of the effectors may modulate highly conserved eukaryotic processes, while others may target protist-specific processes that are absent in mammals. The lack of studies to determine the role of the effectors in adaptation of L. pneumophila to various protists has hampered the progress to determine the function of most of these effectors, which are routinely studied in mouse or human macrophages. Since many protists restrict L. pneumophila, utilization of such hosts can also be instrumental in deciphering the mechanisms of failure of L. pneumophila to overcome restriction of certain protist hosts. Here, we review the interaction of L. pneumophila with its permissive and restrictive protist environmental hosts and outline the accomplishments as well as gaps in our knowledge of L. pneumophila-protist host interaction and L. pneumophila's evolution to become a human pathogen.
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Affiliation(s)
- Ashley Best
- Department of Microbiology and Immunology, School of Medicine, University of Louisville, Louisville, Kentucky, USA
| | - Yousef Abu Kwaik
- Department of Microbiology and Immunology, School of Medicine, University of Louisville, Louisville, Kentucky, USA
- Center for Predictive Medicine, University of Louisville, Louisville, Kentucky, USA
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Bojko J, Dunn AM, Stebbing PD, van Aerle R, Bacela-Spychalska K, Bean TP, Urrutia A, Stentiford GD. ‘Candidatus Aquirickettsiella gammari’ (Gammaproteobacteria: Legionellales: Coxiellaceae): A bacterial pathogen of the freshwater crustacean Gammarus fossarum (Malacostraca: Amphipoda). J Invertebr Pathol 2018; 156:41-53. [DOI: 10.1016/j.jip.2018.07.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 07/06/2018] [Accepted: 07/10/2018] [Indexed: 01/24/2023]
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25
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Younas F, Soltanmohammadi N, Knapp O, Benz R. The major outer membrane protein of Legionella pneumophila Lpg1974 shows pore-forming characteristics similar to the human mitochondrial outer membrane pore, hVDAC1. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1544-1553. [PMID: 29787733 DOI: 10.1016/j.bbamem.2018.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 05/17/2018] [Accepted: 05/18/2018] [Indexed: 10/16/2022]
Abstract
Legionella pneumophila is an aerobic and nonspore-forming pathogenic Gram-negative bacterium of the genus Legionella. It is the causative agent of Legionnaires' disease, also known as Legionellosis. The hosts of this organism are diverse, ranging from simple water borne protozoans such as amoebae to more complex hosts such as macrophages in humans. Genome analyses have shown the presence of genes coding for eukaryotic like proteins in several Legionella species. The presence of these proteins may assist L. pneumophila in its adaptation to the eukaryotic host. We studied the characteristics of a protein (Lpg1974) of L. pneumophila that shows remarkable homologies in length of the primary sequence and for the identity/homology of many amino acids to the voltage dependent anion channel (human VDAC1, Porin 31HL) of human mitochondria. Two different forms of Lpg1974 were overexpressed in Escherichia coli and purified to homogeneity: the one containing a putative N-terminal signal sequence and one without it. Reconstituted protein containing the signal sequence formed ion-permeable pores in lipid bilayer membranes with a conductance of approximately 5.4 nS in 1 M KCl. When the predicted N-terminal signal peptide of Lpg1974 comprising an α-helical structure similar to that at the N-terminus of hVDAC1 was removed, the channels formed in reconstitution experiments had a conductance of 7.6 nS in 1 M KCl. Both Lpg1974 proteins formed pores that were voltage-dependent and anion-selective similar to the pores formed by hVDAC1. These results suggest that Lpg1974 of L. pneumophila is indeed a structural and functional homologue to hVDAC1.
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Affiliation(s)
- Farhan Younas
- Department of Life Sciences and Chemistry, Jacobs University, Campusring 1, 28759 Bremen, Germany
| | - Nafiseh Soltanmohammadi
- Department of Life Sciences and Chemistry, Jacobs University, Campusring 1, 28759 Bremen, Germany
| | - Oliver Knapp
- Department of Life Sciences and Chemistry, Jacobs University, Campusring 1, 28759 Bremen, Germany
| | - Roland Benz
- Department of Life Sciences and Chemistry, Jacobs University, Campusring 1, 28759 Bremen, Germany.
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Virulence Traits of Environmental and Clinical Legionella pneumophila Multilocus Variable-Number Tandem-Repeat Analysis (MLVA) Genotypes. Appl Environ Microbiol 2018. [PMID: 29523542 DOI: 10.1128/aem.00429-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Legionella pneumophila causes water-based infections resulting in severe pneumonia. Recently, we showed that different MLVA-8 (multilocus variable-number tandem-repeat analysis using 8 loci) genotypes dominated different sites of a drinking-water distribution system. Each genotype displayed a unique temperature-dependent growth behavior. Here we compared the pathogenicity potentials of different MLVA-8 genotypes of environmental and clinical strains. The virulence traits studied were hemolytic activity and cytotoxicity toward amoebae and macrophages. Clinical strains were significantly more hemolytic than environmental strains, while their cytotoxicity toward amoebae was significantly lower at 30°C. No significant differences were detected between clinical and environmental strains in cytotoxicity toward macrophages. Significant differences in virulence were observed between the environmental genotypes (Gt). Gt15 strains showed a significantly higher hemolytic activity. In contrast, Gt4 and Gt6 strains were more infective toward Acanthamoeba castellanii Moreover, Gt4 strains exhibited increased cytotoxicity toward macrophages and demonstrated a broader temperature range of amoebal lysis than Gt6 and Gt15 strains. Understanding the virulence traits of Legionella genotypes may improve the assessment of public health risks of Legionella in drinking water.IMPORTANCELegionella pneumophila is the causative agent of a severe form of pneumonia. Here we demonstrated that clinical strains were significantly more cytotoxic toward red blood cells than environmental strains, while their cytotoxicity toward macrophages was similar. Genotype 4 (Gt4) strains were highly cytotoxic toward amoebae and macrophages and lysed amoebae in a broader temperature range than to the other studied genotypes. The results can explain the relatively high success of Gt4 in the environment and in clinical samples; thus, Gt4 strains should be considered a main factor for the assessment of public health risks of Legionella in drinking water. Our findings shed light on the ecology, virulence, and pathogenicity potential of different L. pneumophila genotypes, which can be a valuable parameter for future modeling and quantitative microbial risk assessment of Legionella in drinking-water systems.
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Wang Z, Wu M. Comparative Genomic Analysis of Acanthamoeba Endosymbionts Highlights the Role of Amoebae as a "Melting Pot" Shaping the Rickettsiales Evolution. Genome Biol Evol 2018; 9:3214-3224. [PMID: 29177480 PMCID: PMC5751055 DOI: 10.1093/gbe/evx246] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/20/2017] [Indexed: 11/12/2022] Open
Abstract
Amoebae have been considered as a genetic "melting pot" for its symbionts, facilitating genetic exchanges of the bacteria that co-inhabit the same host. To test the "melting pot" hypothesis, we analyzed six genomes of amoeba endosymbionts within Rickettsiales, four of which belong to Holosporaceae family and two to Candidatus Midichloriaceae. For the first time, we identified plasmids in obligate amoeba endosymbionts, which suggests conjugation as a potential mechanism for lateral gene transfers (LGTs) that underpin the "melting pot" hypothesis. We found strong evidence of recent LGTs between the Rickettsiales amoeba endosymbionts, suggesting that the LGTs are continuous and ongoing. In addition, comparative genomic and phylogenomic analyses revealed pervasive and recurrent LGTs between Rickettsiales and distantly related amoeba-associated bacteria throughout the Rickettsiales evolution. Many of these exchanged genes are important for amoeba-symbiont interactions, including genes in transport system, antibiotic resistance, stress response, and bacterial virulence, suggesting that LGTs have played important roles in the adaptation of endosymbionts to their intracellular habitats. Surprisingly, we found little evidence of LGTs between amoebae and their bacterial endosymbionts. Our study strongly supports the "melting pot" hypothesis and highlights the role of amoebae in shaping the Rickettsiales evolution.
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Affiliation(s)
- Zhang Wang
- Department of Biology, University of Virginia
| | - Martin Wu
- Department of Biology, University of Virginia
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28
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Knowledge to Predict Pathogens: Legionella pneumophila Lifecycle Critical Review Part I Uptake into Host Cells. WATER 2018. [DOI: 10.3390/w10020132] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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29
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Oliva G, Sahr T, Buchrieser C. The Life Cycle of L. pneumophila: Cellular Differentiation Is Linked to Virulence and Metabolism. Front Cell Infect Microbiol 2018; 8:3. [PMID: 29404281 PMCID: PMC5780407 DOI: 10.3389/fcimb.2018.00003] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Accepted: 01/05/2018] [Indexed: 12/20/2022] Open
Abstract
Legionella pneumophila is a gram-negative bacterium that inhabits freshwater ecosystems, where it is present in biofilm or as planktonic form. L. pneumophila is mainly found associated with protozoa, which serve as protection from hostile environments and as replication niche. If inhaled within aerosols, L. pneumophila is also able to infect and replicate in human alveolar macrophages, eventually causing the Legionnaires' disease. The transition between intracellular and extracellular environments triggers a differentiation program in which metabolic as well as morphogenetic changes occur. We here describe the current knowledge on how the different developmental states of this bacterium are regulated, with a particular emphasis on the stringent response activated during the transition from the replicative phase to the infectious phase and the metabolic features going in hand. We propose that the cellular differentiation of this intracellular pathogen is closely associated to key metabolic changes in the bacterium and the host cell, which together have a crucial role in the regulation of L. pneumophila virulence.
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Affiliation(s)
- Giulia Oliva
- Institut Pasteur, Biologie des Bactéries Intracellulaires, Paris, France.,Centre National de la Recherche Scientifique, UMR 3525, Paris, France
| | - Tobias Sahr
- Institut Pasteur, Biologie des Bactéries Intracellulaires, Paris, France.,Centre National de la Recherche Scientifique, UMR 3525, Paris, France
| | - Carmen Buchrieser
- Institut Pasteur, Biologie des Bactéries Intracellulaires, Paris, France.,Centre National de la Recherche Scientifique, UMR 3525, Paris, France
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30
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Hiller M, Lang C, Michel W, Flieger A. Secreted phospholipases of the lung pathogen Legionella pneumophila. Int J Med Microbiol 2017; 308:168-175. [PMID: 29108710 DOI: 10.1016/j.ijmm.2017.10.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 10/06/2017] [Accepted: 10/22/2017] [Indexed: 11/28/2022] Open
Abstract
Legionella pneumophila is an intracellular pathogen and the main causative agent of Legionnaires' disease, a potentially fatal pneumonia. The bacteria infect both mammalian cells and environmental hosts, such as amoeba. Inside host cells, the bacteria withstand the multifaceted defenses of the phagocyte and replicate within a unique membrane-bound compartment, the Legionella-containing vacuole (LCV). For establishment and maintenance of the infection, L. pneumophila secretes many proteins including effector proteins by means of different secretion systems and outer membrane vesicles. Among these are a large variety of lipolytic enzymes which possess phospholipase/lysophospholipase and/or glycerophospholipid:cholesterol acyltransferase activities. Secreted lipolytic activities may contribute to bacterial virulence, for example via modification of eukaryotic membranes, such as the LCV. In this review, we describe the secretion systems of L. pneumophila, introduce the classification of phospholipases, and summarize the state of the art on secreted L. pneumophila phospholipases. We especially highlight those enzymes secreted via the type II secretion system Lsp, via the type IVB secretion system Dot/Icm, via outer membrane vesicles, and such where the mode of secretion has not yet been defined. We also give an overview on the complexity of their activities, activation mechanisms, localization, growth-phase dependent abundance, and their role in infection.
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Affiliation(s)
- Miriam Hiller
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch-Institute, Burgstraße 37, 38855 Wernigerode, Germany
| | - Christina Lang
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch-Institute, Burgstraße 37, 38855 Wernigerode, Germany
| | - Wiebke Michel
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch-Institute, Burgstraße 37, 38855 Wernigerode, Germany
| | - Antje Flieger
- Division of Enteropathogenic Bacteria and Legionella, Robert Koch-Institute, Burgstraße 37, 38855 Wernigerode, Germany.
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31
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Collins S, Stevenson D, Walker J, Bennett A. Evaluation ofLegionellareal-time PCR against traditional culture for routine and public health testing of water samples. J Appl Microbiol 2017; 122:1692-1703. [DOI: 10.1111/jam.13461] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/25/2017] [Accepted: 03/27/2017] [Indexed: 11/29/2022]
Affiliation(s)
- S. Collins
- Biosafety Air and Water Microbiology Group; Public Health England; Porton Down Salisbury UK
| | - D. Stevenson
- Biosafety Air and Water Microbiology Group; Public Health England; Porton Down Salisbury UK
| | - J. Walker
- Biosafety Air and Water Microbiology Group; Public Health England; Porton Down Salisbury UK
| | - A. Bennett
- Biosafety Air and Water Microbiology Group; Public Health England; Porton Down Salisbury UK
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32
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Mohabati Mobarez A, Ahmadrajabi R, Khoramabadi N, Salmanian AH. Protection against Legionnaire's Disease: Recombinant Flagellin A of Legionella pneumophila Can Induce Protective Immunity against Bacteremia in a BALB/c Murine Model. J Mol Microbiol Biotechnol 2017; 27:110-116. [DOI: 10.1159/000460295] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 02/08/2017] [Indexed: 11/19/2022] Open
Abstract
To investigate the immunoprotective effects of the recombinant type A flagellin (FLA), the <i>fla</i>A gene of <i>Legionella pneumophila</i> serogroup 1 strain Paris was cloned into pET28a(+). Recombinant FLA (rFLA) was overexpressed in <i>E. coli</i> BL21 (DE3) and purified by Ni<sup>2+</sup> exchange chromatography. Female BALB/c aged 6-8 weeks were immunized with 20 μg of rFLA. Nonimmunized mice along with mice inoculated with a sublethal dose of live <i>L. pneumophila</i> intravenously were considered as negative and positive controls, respectively. A significant serum antibody response was observed in female BALB/c mice immunized with rFLA. Production of IFN-γ and IL-12, and TNF-α in the serum and the splenocyte cultures, and antigen-specific splenocyte proliferation suggested a strong innate and adaptive cell-mediated immunity response in rFLA-immunized mice. Intravenous lethal challenge with <i>L. pneumophila</i> serogroup 1 (strain Paris) showed that 60% of mice immunized with rFLA survived in a 10-day follow-up survey. These results show that rFLA from <i>L. pneumophila</i> can elicit strong innate and adaptive immune responses and suggest the possibility of a long-term immunity against lethal challenge with <i>L. pneumophila</i>.
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33
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Lukman S, Nguyen MN, Sim K, Teo JCM. Discovery of Rab1 binding sites using an ensemble of clustering methods. Proteins 2017; 85:859-871. [PMID: 28120477 DOI: 10.1002/prot.25254] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 12/28/2016] [Accepted: 01/19/2017] [Indexed: 12/29/2022]
Abstract
Targeting non-native-ligand binding sites for potential investigative and therapeutic applications is an attractive strategy in proteins that share common native ligands, as in Rab1 protein. Rab1 is a subfamily member of Rab proteins, which are members of Ras GTPase superfamily. All Ras GTPase superfamily members bind to native ligands GTP and GDP, that switch on and off the proteins, respectively. Rab1 is physiologically essential for autophagy and transport between endoplasmic reticulum and Golgi apparatus. Pathologically, Rab1 is implicated in human cancers, a neurodegenerative disease, cardiomyopathy, and bacteria-caused infectious diseases. We have performed structural analyses on Rab1 protein using a unique ensemble of clustering methods, including multi-step principal component analysis, non-negative matrix factorization, and independent component analysis, to better identify representative Rab1 proteins than the application of a single clustering method alone does. We then used the identified representative Rab1 structures, resolved in multiple ligand states, to map their known and novel binding sites. We report here at least a novel binding site on Rab1, involving Rab1-specific residues that could be further explored for the rational design and development of investigative probes and/or therapeutic small molecules against the Rab1 protein. Proteins 2017; 85:859-871. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Suryani Lukman
- Khalifa University, Abu Dhabi Campus, PO Box, 127788, Abu Dhabi, United Arab Emirates
| | - Minh N Nguyen
- Bioinformatics Institute, Agency for Science, Technology and Research, 30 Biopolis Street, #07-01 Matrix, Singapore, 138671, Singapore
| | - Kelvin Sim
- OneAnalytix Pte Ltd, Onn Wah Building #04-01, 11 Changi South Lane Singapore, 486154, Singapore
| | - Jeremy C M Teo
- Khalifa University, Abu Dhabi Campus, PO Box, 127788, Abu Dhabi, United Arab Emirates
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34
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Mizrahi H, Peretz A, Lesnik R, Aizenberg-Gershtein Y, Rodríguez-Martínez S, Sharaby Y, Pastukh N, Brettar I, Höfle MG, Halpern M. Comparison of sputum microbiome of legionellosis-associated patients and other pneumonia patients: indications for polybacterial infections. Sci Rep 2017; 7:40114. [PMID: 28059171 PMCID: PMC5216348 DOI: 10.1038/srep40114] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 12/02/2016] [Indexed: 02/08/2023] Open
Abstract
Bacteria of the genus Legionella cause water-based infections resulting in severe pneumonia. Here we analyze and compare the bacterial microbiome of sputum samples from pneumonia patients in relation to the presence and abundance of the genus Legionella. The prevalence of Legionella species was determined by culture, PCR, and Next Generation Sequencing (NGS). Nine sputum samples out of the 133 analyzed were PCR-positive using Legionella genus-specific primers. Only one sample was positive by culture. Illumina MiSeq 16S rRNA gene sequencing analyses of Legionella-positive and Legionella-negative sputum samples, confirmed that indeed, Legionella was present in the PCR-positive sputum samples. This approach allowed the identification of the sputum microbiome at the genus level, and for Legionella genus at the species and sub-species level. 42% of the sputum samples were dominated by Streptococcus. Legionella was never the dominating genus and was always accompanied by other respiratory pathogens. Interestingly, sputum samples that were Legionella positive were inhabited by aquatic bacteria that have been observed in an association with amoeba, indicating that amoeba might have transferred Legionella from the drinking water together with its microbiome. This is the first study that demonstrates the sputum major bacterial commensals and pathogens profiles with regard to Legionella presence.
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Affiliation(s)
- Hila Mizrahi
- Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Mount Carmel, Haifa, Israel
- Microbiology Lab, Baruch Padeh Medical Center, Poriya, affiliated with the Faculty of Medicine, Bar Ilan University, Israel
| | - Avi Peretz
- Microbiology Lab, Baruch Padeh Medical Center, Poriya, affiliated with the Faculty of Medicine, Bar Ilan University, Israel
| | - René Lesnik
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany
| | - Yana Aizenberg-Gershtein
- Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Mount Carmel, Haifa, Israel
| | - Sara Rodríguez-Martínez
- Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Mount Carmel, Haifa, Israel
| | - Yehonatan Sharaby
- Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Mount Carmel, Haifa, Israel
| | - Nina Pastukh
- Microbiology Lab, Baruch Padeh Medical Center, Poriya, affiliated with the Faculty of Medicine, Bar Ilan University, Israel
| | - Ingrid Brettar
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany
| | - Manfred G. Höfle
- Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany
| | - Malka Halpern
- Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Mount Carmel, Haifa, Israel
- Department of Biology and Environment, Faculty of Natural Sciences, University of Haifa, Oranim, Tivon, Israel
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35
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Collins S, Jorgensen F, Willis C, Walker J. Real-time PCR to supplement gold-standard culture-based detection of Legionella
in environmental samples. J Appl Microbiol 2015. [DOI: 10.1111/jam.12911] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- S. Collins
- Public Health England; Biosafety Investigation Unit; Salisbury UK
- Public Health England; Food, Water and Environmental Microbiology Laboratory; Salisbury UK
| | - F. Jorgensen
- Public Health England; Food, Water and Environmental Microbiology Laboratory; Salisbury UK
| | - C. Willis
- Public Health England; Food, Water and Environmental Microbiology Laboratory; Salisbury UK
| | - J. Walker
- Public Health England; Biosafety Investigation Unit; Salisbury UK
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36
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Hellinga JR, Garduño RA, Kormish JD, Tanner JR, Khan D, Buchko K, Jimenez C, Pinette MM, Brassinga AKC. Identification of vacuoles containing extraintestinal differentiated forms of Legionella pneumophila in colonized Caenorhabditis elegans soil nematodes. Microbiologyopen 2015; 4:660-81. [PMID: 26131925 PMCID: PMC4554460 DOI: 10.1002/mbo3.271] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 05/13/2015] [Accepted: 05/19/2015] [Indexed: 11/24/2022] Open
Abstract
Legionella pneumophila, a causative agent of Legionnaires’ disease, is a facultative intracellular parasite of freshwater protozoa. Legionella pneumophila features a unique developmental network that involves several developmental forms including the infectious cyst forms. Reservoirs of L. pneumophila include natural and man-made freshwater systems; however, recent studies have shown that isolates of L. pneumophila can also be obtained directly from garden potting soil suggesting the presence of an additional reservoir. A previous study employing the metazoan Caenorhabditis elegans, a member of the Rhabditidae family of free-living soil nematodes, demonstrated that the intestinal lumen can be colonized with L. pneumophila. While both replicative forms and differentiated forms were observed in C. elegans, these morphologically distinct forms were initially observed to be restricted to the intestinal lumen. Using live DIC imaging coupled with focused transmission electron microscopy analyses, we report here that L. pneumophila is able to invade and establish Legionella-containing vacuoles (LCVs) in the intestinal cells. In addition, LCVs containing replicative and differentiated cyst forms were observed in the pseudocoelomic cavity and gonadal tissue of nematodes colonized with L. pneumophila. Furthermore, establishment of LCVs in the gonadal tissue was Dot/Icm dependent and required the presence of the endocytic factor RME-1 to gain access to maturing oocytes. Our findings are novel as this is the first report, to our knowledge, of extraintestinal LCVs containing L. pneumophila cyst forms in C. elegans tissues, highlighting the potential of soil-dwelling nematodes as an alternate environmental reservoir for L. pneumophila.
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Affiliation(s)
- Jacqueline R Hellinga
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada, R3T 2N2
| | - Rafael A Garduño
- Department of Microbiology and Immunology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 1X5.,Department of Medicine, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 1X5
| | - Jay D Kormish
- Department of Biological Sciences, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada, R3T 2N2
| | - Jennifer R Tanner
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada, R3T 2N2
| | - Deirdre Khan
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada, R3T 2N2
| | - Kristyn Buchko
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada, R3T 2N2
| | - Celine Jimenez
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada, R3T 2N2
| | - Mathieu M Pinette
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada, R3T 2N2
| | - Ann Karen C Brassinga
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada, R3T 2N2
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37
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Legionellosis in Patients With Cancer. INFECTIOUS DISEASES IN CLINICAL PRACTICE 2015. [DOI: 10.1097/ipc.0000000000000223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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38
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Zinicola M, Lima F, Lima S, Machado V, Gomez M, Döpfer D, Guard C, Bicalho R. Altered microbiomes in bovine digital dermatitis lesions, and the gut as a pathogen reservoir. PLoS One 2015; 10:e0120504. [PMID: 25781328 PMCID: PMC4362943 DOI: 10.1371/journal.pone.0120504] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 01/23/2015] [Indexed: 12/16/2022] Open
Abstract
Bovine digital dermatitis (DD) is the most important infectious disease associated with lameness in cattle worldwide. Since the disease was first described in 1974, a series of Treponema species concurrent with other microbes have been identified in DD lesions, suggesting a polymicrobial etiology. However, the pathogenesis of DD and the source of the causative microbes remain unclear. Here we characterized the microbiomes of healthy skin and skin lesions in dairy cows affected with different stages of DD and investigated the gut microbiome as a potential reservoir for microbes associated with this disease. Discriminant analysis revealed that the microbiomes of healthy skin, active DD lesions (ulcerative and chronic ulcerative) and inactive DD lesions (healing and chronic proliferative) are completely distinct. Treponema denticola, Treponema maltophilum, Treponema medium, Treponema putidum, Treponema phagedenis and Treponema paraluiscuniculi were all found to be present in greater relative abundance in active DD lesions when compared with healthy skin and inactive DD lesions, and these same Treponema species were nearly ubiquitously present in rumen and fecal microbiomes. The relative abundance of Candidatus Amoebophilus asiaticus, a bacterium not previously reported in DD lesions, was increased in both active and inactive lesions when compared with healthy skin. In conclusion, our data support the concept that DD is a polymicrobial disease, with active DD lesions having a markedly distinct microbiome dominated by T. denticola, T. maltophilum, T. medium, T. putidum, T. phagedenis and T. paraluiscuniculi. Furthermore, these Treponema species are nearly ubiquitously found in rumen and fecal microbiomes, suggesting that the gut is an important reservoir of microbes involved in DD pathogenesis. Additionally, the bacterium Candidatus Amoebophilus asiaticus was highly abundant in active and inactive DD lesions.
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Affiliation(s)
- Martin Zinicola
- Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, New York, United States of America
| | - Fabio Lima
- Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, New York, United States of America
| | - Svetlana Lima
- Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, New York, United States of America
| | - Vinicius Machado
- Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, New York, United States of America
| | - Marilia Gomez
- Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, New York, United States of America
| | - Dörte Döpfer
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Charles Guard
- Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, New York, United States of America
| | - Rodrigo Bicalho
- Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca, New York, United States of America
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Schlusselhuber M, Humblot V, Casale S, Méthivier C, Verdon J, Leippe M, Berjeaud JM. Potent antimicrobial peptides against Legionella pneumophila and its environmental host, Acanthamoeba castellanii. Appl Microbiol Biotechnol 2015; 99:4879-91. [PMID: 25592737 DOI: 10.1007/s00253-015-6381-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 11/20/2014] [Accepted: 12/31/2014] [Indexed: 11/24/2022]
Abstract
Legionella pneumophila, the major causative agent of Legionnaires' disease, is most often found in the environment in close association with free-living amoebae, leading to persistence, spread, biocide resistance, and elevated virulence of the bacterium. In the present study, we evaluated the anti-Legionella and anti-Acanthamoeba activities of three alpha-helical antimicrobial peptides (AMPs), namely, NK-2, Ci-MAM-A24, and Ci-PAP-A22, already known for the extraordinary efficacy against other microbes. Our data represent the first demonstration of the activity of a particular AMP against both the human facultative intracellular pathogen L. pneumophila and its pathogenic host, Acanthamoeba castellanii. Interestingly, the most effective peptide, Ci-MAM-A24, was also found to reduce the Legionella cell number within amoebae. Accordingly, this peptide was immobilized on gold surfaces to assess its antimicrobial activity. Surfaces were characterized, and activity studies revealed that the potent bactericidal activity of the peptide was conserved after its immobilization. In the frame of elaborating anti-Legionella surfaces, Ci-MAM-A24 represents, by its direct and indirect activity against Legionella, a potent peptide template for biological control of the bacterium in plumbings.
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Affiliation(s)
- Margot Schlusselhuber
- Laboratoire Ecologie & Biologie des Interactions, UMR CNRS 7267, Equipe Microbiologie de l'Eau, Université de Poitiers, 1 Rue Georges Bonnet, TSA 51106, 86073, Poitiers Cedex 9, France
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40
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Epalle T, Girardot F, Allegra S, Maurice-Blanc C, Garraud O, Riffard S. Viable but not culturable forms of Legionella pneumophila generated after heat shock treatment are infectious for macrophage-like and alveolar epithelial cells after resuscitation on Acanthamoeba polyphaga. MICROBIAL ECOLOGY 2015; 69:215-224. [PMID: 25074793 DOI: 10.1007/s00248-014-0470-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 07/18/2014] [Indexed: 06/03/2023]
Abstract
Legionella pneumophila, the causative agent of legionellosis is transmitted to human through aerosols from environmental sources and invades lung's macrophages. It also can invade and replicate within various protozoan species in environmental reservoirs. Following exposures to various stresses, L. pneumophila enters a non-replicative viable but non-culturable (VBNC) state. Here, we evaluated whether VBNC forms of three L. pneumophila serogroup 1 strains (Philadelphia GFP 008, clinical 044 and environmental RNN) infect differentiated macrophage-like cell lines (U937 and HL-60), A549 alveolar cells and Acanthamoeba polyphaga. VBNC forms obtained following shocks at temperatures ranging from 50 to 70 °C for 5 to 60 min were quantified using a flow cytometric assay (FCA). Their loss of culturability was checked on BCYE agar medium. VBNC forms were systematically detected upon a 70 °C heat shock for 30 min. When testing their potential to resuscitate upon amoebal infection, VBNC forms obtained after 30 min at 70 °C were re-cultivated except for the clinical strain. No resuscitation or cell lysis was evidenced when using U937, HL-60, or A549 cells despite the use of various contact times and culture media. None of the strains tested could infect A. polyphaga, macrophage-like or alveolar epithelial cells after a 60-min treatment at 70 °C. However, heat-treated VBNC forms were able to infect macrophage-like or alveolar epithelial cells following their resuscitation on A. polyphaga. These results suggest that heat-generated VBNC forms of L. pneumophila (i) are not infectious for macrophage-like or alveolar epithelial cells in vitro although resuscitation is still possible using amoeba, and (ii) may become infectious for human cell lines following a previous interaction with A. polyphaga.
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Affiliation(s)
- Thibaut Epalle
- Groupe Immunité des Muqueuses et Agents Pathogènes (GIMAP), EA 3064, SFR 143, University of Lyon, 42023, Saint-Etienne, France
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41
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Robertson P, Abdelhady H, Garduño RA. The many forms of a pleomorphic bacterial pathogen-the developmental network of Legionella pneumophila. Front Microbiol 2014; 5:670. [PMID: 25566200 PMCID: PMC4273665 DOI: 10.3389/fmicb.2014.00670] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 11/18/2014] [Indexed: 01/18/2023] Open
Abstract
Legionella pneumophila is a natural intracellular bacterial parasite of free-living freshwater protozoa and an accidental human pathogen that causes Legionnaires' disease. L. pneumophila differentiates, and does it in style. Recent experimental data on L. pneumophila's differentiation point at the existence of a complex network that involves many developmental forms. We intend readers to: (i) understand the biological relevance of L. pneumophila's forms found in freshwater and their potential to transmit Legionnaires' disease, and (ii) learn that the common depiction of L. pneumophila's differentiation as a biphasic developmental cycle that alternates between a replicative and a transmissive form is but an oversimplification of the actual process. Our specific objectives are to provide updates on the molecular factors that regulate L. pneumophila's differentiation (Section The Differentiation Process and Its Regulation), and describe the developmental network of L. pneumophila (Section Dissecting Lp's Developmental Network), which for clarity's sake we have dissected into five separate developmental cycles. Finally, since each developmental form seems to contribute differently to the human pathogenic process and the transmission of Legionnaires' disease, readers are presented with a challenge to develop novel methods to detect the various L. pneumophila forms present in water (Section Practical Implications), as a means to improve our assessment of risk and more effectively prevent legionellosis outbreaks.
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Affiliation(s)
- Peter Robertson
- Department of Microbiology and Immunology, Dalhousie University Halifax, NS, Canada
| | - Hany Abdelhady
- Department of Microbiology and Immunology, Dalhousie University Halifax, NS, Canada
| | - Rafael A Garduño
- Department of Microbiology and Immunology, Dalhousie University Halifax, NS, Canada ; Division of Infectious Diseases, Department of Medicine, Dalhousie University Halifax, NS, Canada
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Whiley H, Keegan A, Fallowfield H, Ross K. Uncertainties associated with assessing the public health risk from Legionella. Front Microbiol 2014; 5:501. [PMID: 25309526 PMCID: PMC4174118 DOI: 10.3389/fmicb.2014.00501] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 09/05/2014] [Indexed: 11/13/2022] Open
Abstract
Legionella is an opportunistic pathogen of public health concern. Current regulatory and management guidelines for the control of this organism are informed by risk assessments. However, there are many unanswered questions and uncertainties regarding Legionella epidemiology, strain infectivity, infectious dose, and detection methods. This review follows the EnHealth Risk Assessment Framework, to examine the current information available regarding Legionella risk and discuss the uncertainties and assumptions. This review can be used as a tool for understanding the uncertainties associated with Legionella risk assessment. It also serves to highlight the areas of Legionella research that require future focus. Improvement of these uncertainties will provide information to enhance risk management practices for Legionella, potentially improving public health protection and reducing the economic costs by streamlining current management practices.
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Affiliation(s)
- Harriet Whiley
- Health and the Environment, Flinders UniversityAdelaide, SA, Australia
| | | | | | - Kirstin Ross
- Health and the Environment, Flinders UniversityAdelaide, SA, Australia
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Thomas JM, Thomas T, Stuetz RM, Ashbolt NJ. Your garden hose: a potential health risk due to Legionella spp. growth facilitated by free-living amoebae. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:10456-10464. [PMID: 25075763 DOI: 10.1021/es502652n] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Common garden hoses may generate aerosols of inhalable size (≤10 μm) during use. If humans inhale aerosols containing Legionella bacteria, Legionnaires' disease or Pontiac fever may result. Clinical cases of these illnesses have been linked to garden hose use. The hose environment is ideal for the growth and interaction of Legionella and free-living amoebae (FLA) due to biofilm formation, elevated temperatures, and stagnation of water. However, the microbial densities and hose conditions necessary to quantify the human health risks have not been reported. Here we present data on FLA and Legionella spp. detected in water and biofilm from two types of garden hoses over 18 months. By culturing and qPCR, two genera of FLA were introduced via the drinking water supply and reached mean densities of 2.5 log10 amoebae·mL(-1) in garden hose water. Legionella spp. densities (likely including pathogenic L. pneumophila) were significantly higher in one type of hose (3.8 log10 cells·mL(-1), p < 0.0001). A positive correlation existed between Vermamoebae vermiformis densities and Legionella spp. densities (r = 0.83, p < 0.028). The densities of Legionella spp. identified in the hoses were similar to those reported during legionellosis outbreaks in other situations. Therefore, we conclude that there is a health risk to susceptible users from the inhalation of garden hose aerosols.
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Affiliation(s)
- Jacqueline M Thomas
- School of Civil and Environmental Engineering, The University of New South Wales , Sydney, NSW 2052, Australia
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Xayarath B, Freitag NE. Optimizing the balance between host and environmental survival skills: lessons learned from Listeria monocytogenes. Future Microbiol 2014; 7:839-52. [PMID: 22827306 DOI: 10.2217/fmb.12.57] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Environmental pathogens - organisms that survive in the outside environment but maintain the capacity to cause disease in mammals - navigate the challenges of life in habitats that range from water and soil to the cytosol of host cells. The bacterium Listeria monocytogenes has served for decades as a model organism for studies of host-pathogen interactions and for fundamental paradigms of cell biology. This ubiquitous saprophyte has recently become a model for understanding how an environmental bacterium switches to life within human cells. This review describes how L. monocytogenes balances life in disparate environments with the help of a critical virulence regulator known as PrfA. Understanding L. monocytogenes survival strategies is important for gaining insight into how environmental microbes become pathogens.
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Affiliation(s)
- Bobbi Xayarath
- Department of Microbiology & Immunology, University of Illinois at Chicago, Chicago, IL, USA
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45
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Cateau E, Delafont V, Hechard Y, Rodier M. Free-living amoebae: what part do they play in healthcare-associated infections? J Hosp Infect 2014; 87:131-40. [DOI: 10.1016/j.jhin.2014.05.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 05/01/2014] [Indexed: 12/12/2022]
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46
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Free-living amoebae (FLA) co-occurring with legionellae in industrial waters. Eur J Protistol 2014; 50:422-9. [PMID: 25062389 PMCID: PMC4155075 DOI: 10.1016/j.ejop.2014.04.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 04/30/2014] [Accepted: 04/30/2014] [Indexed: 11/23/2022]
Abstract
Legionella pneumophila is known as the causative agent of Legionnaires’ disease and free-living amoebae (FLA) can serve as vehicles for legionellae. The aim of this study was to screen industrial waters for the occurrence of FLA and their co-occurrence with legionellae. A total of 201 water samples, including 129 cooling waters and 72 process waters, and 30 cooling lubricants were included in the study. Treated waters were screened periodically, pre and post treatment. Altogether, 72.6% of the water samples were positive for FLA, acanthamoebae being most prevalent (in 23.9% of the samples) followed by Vermamoeba vermiformis (19.4%). Only one cooling lubricant was positive (Acanthamoeba genotype T4). Legionella spp. were detected in 34.8% of the water samples and in 15% in high concentrations (>1000 CFU/100 ml). Altogether, 81.4% of the Legionella-positive samples were positive for FLA by standard methods. By applying a highly sensitive nested PCR to a representative set of random samples it was revealed that Legionella spp. always co-occurred with Acanthamoeba spp. Although the addition of disinfectants did influence amoebal density and diversity, treated waters showed no difference concerning FLA in the interphases of disinfection. It appears that FLA can re-colonize treated waters within a short period of time.
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47
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Donohue MJ, O'Connell K, Vesper SJ, Mistry JH, King D, Kostich M, Pfaller S. Widespread molecular detection of Legionella pneumophila Serogroup 1 in cold water taps across the United States. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:3145-3152. [PMID: 24548208 DOI: 10.1021/es4055115] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In the United States, 6,868 cases of legionellosis were reported to the Center for Disease Control and Prevention in 2009-2010. Of these reports, it is estimated that 84% are caused by the microorganism Legionella pneumophila Serogroup (Sg) 1. Legionella spp. have been isolated and recovered from a variety of natural freshwater environments. Human exposure to L. pneumophila Sg1 may occur from aerosolization and subsequent inhalation of household and facility water. In this study, two primer/probe sets (one able to detect L. pneumophila and the other L. pneumophila Sg1) were determined to be highly sensitive and selective for their respective targets. Over 272 water samples, collected in 2009 and 2010 from 68 public and private water taps across the United States, were analyzed using the two qPCR assays to evaluate the incidence of L. pneumophila Sg1. Nearly half of the taps showed the presence of L. pneumophila Sg1 in one sampling event, and 16% of taps were positive in more than one sampling event. This study is the first United States survey to document the occurrence and colonization of L. pneumophila Sg1 in cold water delivered from point of use taps.
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Affiliation(s)
- Maura J Donohue
- Office of Research and Development, National Exposure Research Laboratory, United States Environmental Protection Agency , 26 West Martin Luther King Drive, Mail Stop 593, Cincinnati, Ohio 45268, United States
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Alleron L, Khemiri A, Koubar M, Lacombe C, Coquet L, Cosette P, Jouenne T, Frere J. VBNC Legionella pneumophila cells are still able to produce virulence proteins. WATER RESEARCH 2013; 47:6606-17. [PMID: 24064547 DOI: 10.1016/j.watres.2013.08.032] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Revised: 07/24/2013] [Accepted: 08/27/2013] [Indexed: 05/22/2023]
Abstract
Legionella pneumophila is the agent responsible for legionellosis. Numerous bacteria, including L. pneumophila, can enter into a viable but not culturable (VBNC) state under unfavorable environmental conditions. In this state, cells are unable to form colonies on standard medium but are still alive. Here we show that VBNC L. pneumophila cells, obtained by monochloramine treatment, were still able to synthesize proteins, some of which are involved in virulence. Protein synthesis was measured using (35)S-labeling and the proteomes of VBNC and culturable cells then compared. This analysis allowed the identification of nine proteins that were accumulated in the VBNC state. Among them, four were involved in virulence, i.e., the macrophage infectivity potentiator protein, the hypothetical protein lpl2247, the ClpP protease proteolytic subunit and the 27 kDa outer membrane protein. Others, i.e., the enoyl reductase, the electron transfer flavoprotein (alpha and beta subunits), the 50S ribosomal proteins (L1 and L25) are involved in metabolic and energy production pathways. However, resuscitation experiments performed with Acanthamoeba castellanii failed, suggesting that the accumulation of virulence factors by VBNC cells is not sufficient to maintain their virulence.
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Affiliation(s)
- Laëtitia Alleron
- Laboratoire Ecologie et Biologie des Interactions, UMR CNRS 7267, Equipe Microbiologie de l'Eau, B36, Université de Poitiers, 40 Avenue du Recteur Pineau, 86022 Poitiers Cedex, France
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Harrison CF, Kicka S, Trofimov V, Berschl K, Ouertatani-Sakouhi H, Ackermann N, Hedberg C, Cosson P, Soldati T, Hilbi H. Exploring anti-bacterial compounds against intracellular Legionella. PLoS One 2013; 8:e74813. [PMID: 24058631 PMCID: PMC3772892 DOI: 10.1371/journal.pone.0074813] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Accepted: 08/06/2013] [Indexed: 01/10/2023] Open
Abstract
Legionella pneumophila is a ubiquitous fresh-water bacterium which reproduces within its erstwhile predators, environmental amoeba, by subverting the normal pathway of phagocytosis and degradation. The molecular mechanisms which confer resistance to amoeba are apparently conserved and also allow replication within macrophages. Thus, L. pneumophila can act as an 'accidental' human pathogen and cause a severe pneumonia known as Legionnaires' disease. The intracellular localisation of L. pneumophila protects it from some antibiotics, and this fact must be taken into account to develop new anti-bacterial compounds. In addition, the intracellular lifestyle of L. pneumophila may render the bacteria susceptible to compounds diminishing bacterial virulence and decreasing intracellular survival and replication of this pathogen. The development of a single infection cycle intracellular replication assay using GFP-producing L. pneumophila and Acanthamoebacastellanii amoeba is reported here. This fluorescence-based assay allows for continuous monitoring of intracellular replication rates, revealing the effect of bacterial gene deletions or drug treatment. To examine how perturbations of the host cell affect L. pneumophila replication, several known host-targeting compounds were tested, including modulators of cytoskeletal dynamics, vesicle scission and Ras GTPase localisation. Our results reveal a hitherto unrealized potential antibiotic property of the β-lactone-based Ras depalmitoylation inhibitor palmostatin M, but not the closely related inhibitor palmostatin B. Further characterisation indicated that this compound caused specific growth inhibition of Legionella and Mycobacterium species, suggesting that it may act on a common bacterial target.
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Affiliation(s)
| | - Sébastien Kicka
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Valentin Trofimov
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Kathrin Berschl
- Max von Pettenkofer Institute, Ludwig-Maximilians University, Munich, Germany
| | | | - Nikolaus Ackermann
- Max von Pettenkofer Institute, Ludwig-Maximilians University, Munich, Germany
| | | | - Pierre Cosson
- Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Thierry Soldati
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Hubert Hilbi
- Max von Pettenkofer Institute, Ludwig-Maximilians University, Munich, Germany
- * E-mail:
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Monteil CL, Cai R, Liu H, Llontop MEM, Leman S, Studholme DJ, Morris CE, Vinatzer BA. Nonagricultural reservoirs contribute to emergence and evolution of Pseudomonas syringae crop pathogens. THE NEW PHYTOLOGIST 2013; 199:800-11. [PMID: 23692644 DOI: 10.1111/nph.12316] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Accepted: 04/02/2013] [Indexed: 05/10/2023]
Abstract
While the existence of environmental reservoirs of human pathogens is well established, less is known about the role of nonagricultural environments in emergence, evolution, and spread of crop pathogens. Here, we analyzed phylogeny, virulence genes, host range, and aggressiveness of Pseudomonas syringae strains closely related to the tomato pathogen P. syringae pv. tomato (Pto), including strains isolated from snowpack and streams. The population of Pto relatives in nonagricultural environments was estimated to be large and its diversity to be higher than that of the population of Pto and its relatives on crops. Ancestors of environmental strains, Pto, and other genetically monomorphic crop pathogens were inferred to have frequently recombined, suggesting an epidemic population structure for P. syringae. Some environmental strains have repertoires of type III-secreted effectors very similar to Pto, are almost as aggressive on tomato as Pto, but have a wider host range than typical Pto strains. We conclude that crop pathogens may have evolved through a small number of evolutionary events from a population of less aggressive ancestors with a wider host range present in nonagricultural environments.
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Affiliation(s)
- Caroline L Monteil
- Department of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg, VA, USA
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