Legionella community in cooling tower water
Ontology highlight
ABSTRACT:
PROVIDER: PRJEB14832 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| ERR1539140_1.fastq.gz | Fastqsanger.gz | |||
| ERR1539140_2.fastq.gz | Fastqsanger.gz | |||
| ERR1539150_1.fastq.gz | Fastqsanger.gz | |||
| ERR1539150_2.fastq.gz | Fastqsanger.gz | |||
| ERR1539160_1.fastq.gz | Fastqsanger.gz |
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Project description:Legionella pneumophila (Lp) is an opportunistic pathogen and its survival in water is critical for human infection. Therefore, identifying the genes of Lp that are required for survival in water may help devise strategies to prevent Legionella outbreaks. In this study, we exposed Lp in rich medium and in an artificial freshwater medium (Fraquil) for 2, 6 and 24 hours to uncover the global transcriptomic changes of Lp in water. The repression of major metabolic pathways, such as division, transcription and translation, suggests that Lp enters a dormant state in water. The induction of the flagellar associated genes (flg, fli and mot), enhance entry genes (enh) and some Icm/Dot effectors suggests that Lp may be waiting to establish intracellular replication in suitable host. Moreover, many genes involved in resistance to antibiotic and oxidative stress were induced, suggesting that Lp may be more tolerant to environmental stresses in water. Indeed, Lp exposed to water is more resistant to erythromycin, gentamycin and kanamycin than those cultured in rich medium. Apart from this, the gene bdhA involved in the degradation of the intracellular energy storage compound poly-hydroxybutyrate is highly expressed in water. Further characterization shows that bdhA is positively regulated by RpoS during short-term exposure to water. The deletion mutant of bdhA had a survival defect in water at 37°C, demonstrating that this gene is important for maintaining the long-term survivorship of Lp in water. Other identified genes highly induced upon exposure to water could also be necessary for Lp to survive in water.
2014-11-26 | GSE63622 | GEO
Project description:Colonization and Characteristics of Legionella pneumophila isolated from cooling tower in Japan
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Project description:Legionella pneumophila is a water-borne pathogen, and thus survival in the aquatic environment is central to its transmission to humans. Hence, identifying genes required for its survival in water could help prevent Legionnaires’ disease outbreaks. In the present study, we investigate for the first time the role of the sigma factor RpoS in promoting the survival in water, where L. pneumophila experiences total nutrient deprivation. The rpoS mutant showed a significant survival defect compared to the wild-type strain in defined water medium (DFM). Then, we analyzed the transcriptome of the rpoS mutant during exposure to water using whole genome microarray analysis. We found that RpoS negatively affects the expression of several genes, including genes required for replication, cell division, translation and transcription, suggesting that the mutant fails to shutdown major metabolic programs.
2014-12-04 | GSE56258 | GEO
Project description:Legionella pneumophila (Lp) is an opportunistic pathogen and its survival in water is critical for human infection. Therefore, identifying the genes of Lp that are required for survival in water may help devise strategies to prevent Legionella outbreaks. In this study, we exposed Lp in rich medium and in an artificial freshwater medium (Fraquil) for 2, 6 and 24 hours to uncover the global transcriptomic changes of Lp in water. The repression of major metabolic pathways, such as division, transcription and translation, suggests that Lp enters a dormant state in water. The induction of the flagellar associated genes (flg, fli and mot), enhance entry genes (enh) and some Icm/Dot effectors suggests that Lp may be waiting to establish intracellular replication in suitable host. Moreover, many genes involved in resistance to antibiotic and oxidative stress were induced, suggesting that Lp may be more tolerant to environmental stresses in water. Indeed, Lp exposed to water is more resistant to erythromycin, gentamycin and kanamycin than those cultured in rich medium. Apart from this, the gene bdhA involved in the degradation of the intracellular energy storage compound poly-hydroxybutyrate is highly expressed in water. Further characterization shows that bdhA is positively regulated by RpoS during short-term exposure to water. The deletion mutant of bdhA had a survival defect in water at 37°C, demonstrating that this gene is important for maintaining the long-term survivorship of Lp in water. Other identified genes highly induced upon exposure to water could also be necessary for Lp to survive in water. Legionella pneumophila Philadelphia-1 strain JR32 was grown in AYE broth at 25°C shaking to OD600 of 1 in triplicate. Samples were taken for analysis; this is the control. Then the cultures were washed three times in Fraquil and resuspended in Fraquil to an OD600 of 1 and transfered to vessels of bioreactior (Biostat Q-plus). Samples were taken after 2h, 6h and 24h.
2014-11-26 | E-GEOD-63622 | biostudies-arrayexpress
Project description:Bacterial community characterisation and pathogen profiling in a cooling tower system using an Illumina-based approach
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Project description:Legionella pneumophila is a water-borne pathogen, and thus survival in the aquatic environment is central to its transmission to humans. Hence, identifying genes required for its survival in water could help prevent Legionnaires’ disease outbreaks. In the present study, we investigate for the first time the role of the sigma factor RpoS in promoting the survival in water, where L. pneumophila experiences total nutrient deprivation. The rpoS mutant showed a significant survival defect compared to the wild-type strain in defined water medium (DFM). Then, we analyzed the transcriptome of the rpoS mutant during exposure to water using whole genome microarray analysis. We found that RpoS negatively affects the expression of several genes, including genes required for replication, cell division, translation and transcription, suggesting that the mutant fails to shutdown major metabolic programs. The WT and rpoS mutant were grown to exponential phase in rich AYE broth, washed three times in DFM (NaCl 0.5 g/L, KH2PO40.2 g/L, KCl 0.5 g/L, pH=6.9) and resuspended in DFM at an OD600 of 0.1, After 24h exposure, RNA was extracted.
2014-12-04 | E-GEOD-56258 | biostudies-arrayexpress
Project description:In this report, we have developed a rapid oligonucleotide microarray detection technique to identify the most common ten Legionella spp.. The sensitivity of the detection was at 1.0 ng with genomic DNA or 13 CFU/100 mL with Legionella cultures. The microarray detected seven air conditioner-condensed water samples with 100% accuracy, validating the technique as a promising method for applications in basic microbiology, clinical diagnosis, food safety, and epidemiological surveillance. The phylogenetic study based on the ITS has also revealed interestingly that the non-pathogenic L. fairfieldensis is the closest to L. pneumophila than the nine other pathogenic Legionella spp..
2014-10-04 | GSE61962 | GEO
Project description:Detection and quantification of Pseudomonas species, including P. aeruginosa, in cooling tower water using a genus-specific Illumina-based approach
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Project description:Legionella pneumophila Philadelphia-1 strain was grown to stationary phase in AYE broth and starved in freshwater for 2 hours and RNA was harvested with or without sublethal heat shock via immersion in a 55 degree C hot water bath for 5 minutes
2022-02-15 | GSE196713 | GEO
Project description:Surviving the nutrient-poor aquatic environment for extended periods of time is important for transmission of various water-borne pathogen to the host, including Legionella pneumophila (Lp). Lp is a leading cause of community-acquired and nosocomial pneumonia called Legionnaires’ disease. The remarkable ability of the bacterium to survive in water for periods ranging from several months to years under starvation conditions alludes to regulatory pathways that mediate adaptation to the water environment. In the present study, we investigated a potential role for the LetA/LetS signal transduction system in the successful survival of Lp in water. During infection of host cells, the LetA/LetS two-component system controls the transition from the replicative phase to the transmissive phase in response to nutrient deprivation. In accordance with previous work, the letS mutant used in the present study is defective for pigment production and contributed to cell size reduction in the post-exponential phase. LetS also contributed to cell size reduction when Lp was exposed to water. Importantly, absence of the sensor kinase resulted in a significantly lower survival rate in water at various temperatures, as well as an increase sensitivity to heat shock. Transcriptomic analysis indicated that a general transcriptomic downshift of major pathways is orchestrated by LetA/LetS upon water exposure leading to better survival, suggesting a potential link with the stringent response. However, the expression of the LetA/S regulated small regulatory RNAs RsmY and RsmZ was not changed in a relAspoT mutant, which indicates that the stringent response and the LetA/S response are two distinct regulatory systems important for the survival of Lp in water.
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