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de Oliveira PAA, Baboghlian J, Ramos COA, Mançano ASF, Porcari ADM, Girardello R, Ferraz LFC. Selection and validation of reference genes suitable for gene expression analysis by Reverse Transcription Quantitative real-time PCR in Acinetobacter baumannii. Sci Rep 2024; 14:3830. [PMID: 38360762 PMCID: PMC10869792 DOI: 10.1038/s41598-024-51499-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 01/05/2024] [Indexed: 02/17/2024] Open
Abstract
Acinetobacter baumannii is a Gram-negative bacterium considered an emerging multi-drug-resistant pathogen. Furthermore, this bacterium can survive in extreme environmental conditions, which makes it a frequent cause of nosocomial infection outbreaks. Gene expression analyses by Reverse Transcription Quantitative real-time PCR (RT-qPCR) depend on a reference gene, also called an endogenous gene, which is used to normalize the generated data and thus ensure an accurate analysis with minimal errors. Currently, gene expression analyses in A. baumannii are compromised, as there are no reports in the literature describing the identification of validated reference genes for use in RT-qPCR analyses. For this reason, we selected twelve candidate reference genes of A. baumannii and assessed their expression profile under different experimental and culture conditions. The expression stability of the candidate genes was evaluated by using statistical algorithms such as BestKeeper, geNorm, NormFinder, Delta CT, and RefFinder, in order to identify the most suitable candidate reference genes for RT-qPCR analyses. The statistical analyses indicated rpoB, rpoD, and fabD genes as the most adequate to ensure accurate normalization of RT-qPCR data in A. baumannii. The accuracy of the proposed reference genes was validated by using them to normalize the expression of the ompA gene, encoding the outer membrane protein A, in A. baumannii sensible and resistant to the antibiotic polymyxin. The present work provides suitable reference genes for precise RT-qPCR data normalization on future gene expression studies with A. baumannii.
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Affiliation(s)
| | - Juliana Baboghlian
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, SP, CEP 12916-900, Brazil
| | | | | | - Andréia de Melo Porcari
- Laboratório Multidisciplinar de Pesquisa, Universidade São Francisco, Bragança Paulista, SP, CEP 12916-900, Brazil
| | - Raquel Girardello
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, SP, CEP 12916-900, Brazil
| | - Lúcio Fábio Caldas Ferraz
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, SP, CEP 12916-900, Brazil.
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2
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Manzer HS, Brunetti T, Doran KS. Identification of a DNA-cytosine methyltransferase that impacts global transcription to promote group B streptococcal vaginal colonization. mBio 2023; 14:e0230623. [PMID: 37905908 PMCID: PMC10746215 DOI: 10.1128/mbio.02306-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 09/25/2023] [Indexed: 11/02/2023] Open
Abstract
Group B Streptococcus (GBS) colonizes the female reproductive tract (FRT) and causes adverse pregnancy outcomes and invasive disease following vertical transmission to the fetus or newborn. Despite this major public health burden, the mechanisms of GBS FRT colonization are understudied. A recent transposon sequencing screen identified GBS factors contributing to vaginal colonization and ascending spread, including a putative DNA-cytosine methyltransferase (Dcm). We constructed a Δdcm deletion strain and confirmed that dcm contributes to murine FRT colonization. Investigation of the evolutionary origin of the dcm gene reveals that it is widely distributed across GBS and is encoded as part of a prophage genome that displays evidence of horizontal transfer between GBS strains. We further show that Dcm contributes to 5mC methylation and global regulation of genes involved in carbohydrate metabolism, transcription regulation, and known adhesins and metabolic factors involved in GBS colonization. Interestingly, GBS genes that are induced in the presence of the highly glycosylated vaginal mucin MUC5B were significantly downregulated in the ∆dcm mutant. Furthermore, the ∆dcm mutant exhibited reduced binding to immobilized mucin and was attenuated in its ability to grow on numerous carbon sources including the carbohydrates found on mucins. While the ∆dcm mutant displayed enhanced clearance from the FRT in wild-type mice, there was no significant difference in MUC5B -/- mice, indicating that Dcm-mediated regulation requires MUC5B to promote GBS colonization. This is the first report to characterize the impact of a DNA methyltransferase on GBS gene regulation and FRT colonization. IMPORTANCE Group B Streptococcus (GBS) colonizes the female reproductive tract (FRT) in one-third of women, and carriage leads to numerous adverse pregnancy outcomes including the preterm premature rupture of membranes, chorioamnionitis, and stillbirth. The presence of GBS in the FRT during pregnancy is also the largest predisposing factor for the transmission of GBS and invasive neonatal diseases, including pneumonia, sepsis, and meningitis. The factors contributing to GBS colonization are still being elucidated. Here, we show for the first time that GBS transcription is regulated by an orphan DNA cytosine methyltransferase (Dcm). Many GBS factors are regulated by Dcm, especially those involved in carbohydrate transport and metabolism. We show that GBS persistence in the FRT is dependent on the catabolism of sugars found on the vaginal mucin MUC5B. Collectively, this work highlights the regulatory importance of a DNA methyltransferase and identifies both host and bacterial factors required for GBS colonization.
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Affiliation(s)
- Haider S. Manzer
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Tonya Brunetti
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Kelly S. Doran
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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3
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Alhawas B, Abd El-Hamid MI, Hassan Z, Ibrahim GA, Neamat-Allah ANF, Rizk El-Ghareeb W, Alahmad BAHY, Meligy AMA, Abdel-Raheem SM, Abdel-Moez Ahmed Ismail H, Ibrahim D. Curcumin loaded liposome formulation: Enhanced efficacy on performance, flesh quality, immune response with defense against Streptococcus agalactiae in Nile tilapia (Orechromis niloticus). FISH & SHELLFISH IMMUNOLOGY 2023; 138:108776. [PMID: 37182798 DOI: 10.1016/j.fsi.2023.108776] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/19/2023] [Accepted: 04/24/2023] [Indexed: 05/16/2023]
Abstract
Application of novel trend comprising antioxidant phytogenics is aiming to minimize the stress related factors and associated diseases in intensive fish culturing. Today, the concept of exploiting and protecting natural antioxidants represents a paradigm shift for the aqua feed industry. Therefore, our principal goal targeting liposome as a novel nanocarrier for curcumin is directed to attain superior performance, fillet antioxidant stability and bacterial resistance in Nile tilapia. A total of 500 Nile tilapia fingerlings (average body weight, 10.27 ± 0.10 g) assigned into five experimental groups in 25 glass aquaria of 120 L capacity at the density 20 fish/aquaria. The experimental groups were supplemented with varying doses of liposomal curcumin-NPs, LipoCur-NPs (0, 5, 15, 25 and 35 mg/kg diet) were reared for 12 weeks and later Streptococcus agalactiae (S. agalactiae) challenged model was performed. Inclusion of LipoCur-NPs (25 and 35 mg/kg diet) had the most prominent impact on Nile tilapia growth rate and feed conversion ratio. The immune boosting outcomes post supplementing 35 mg/kg diet of LipoCur-NPs were evidenced by higher myeloperoxidase, lysozyme and total immunoglobulin levels. Even after 4 weeks frozen storage, LipoCur-NPs at the dose of 35 mg/kg diet prominently increased (P < 0.05) the fillet scavenging capability for free radicals (1,1-diphenyl-2-picrylhydrazyl and 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) with an inverse reduction in lipid peroxidation biomarker (malondialdehyde). Notably, upregulation of GSH-Px, CAT, and SOD genes in fillet of 35 mg/kg LipoCur-NPs fed fish coordinated with higher T-AOC and lower oxidative markers (ROS and H2O2). Post S. agalactiae challenge, higher supplementation levels of LipoCur-NPs (35 mg/kg diet) greatly attenuated the expression of its vital virulence genes (cfb, fbsA and cpsA) with higher expression of Igm, CXC-chemokine and MHC genes. Concordantly, downregulation of inflammatory markers (IL-1β, TNF-α and IL-8) and upregulation of anti-inflammatory ones (IL-10 and TGF-β) were remarkably documented. Based on these findings, the innovative curcumin loaded liposome was considered a novel multitargeting alternative not only playing an imperative role in Nile tilapia growth promotion and fillet stability upon storage, but also protecting efficiently against S. agalactiae.
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Affiliation(s)
- Bassam Alhawas
- Department of Public Health, College of Veterinary Medicine, King Faisal University, P.O. Box: 400, Hofuf, Al-Ahsa, 31982, Saudi Arabia.
| | - Marwa I Abd El-Hamid
- Department of Microbiology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, 44511, Egypt.
| | - Zeinab Hassan
- Fish Disease Department, Faculty of Veterinary Medicine, Aswan University, Aswan, 81528, Egypt.
| | - Ghada A Ibrahim
- Department of Bacteriology, Animal Health Research Institute (AHRI), Ismailia Branch, Agriculture Research Center (ARC), Ismailia, 41522, Egypt.
| | - Ahmed N F Neamat-Allah
- Department of Clinical Pathology, Faculty of Veterinary Medicine, Zagazig University, 44511, Zagazig, Egypt
| | - Waleed Rizk El-Ghareeb
- Department of Public Health, College of Veterinary Medicine, King Faisal University, P.O. Box: 400, Hofuf, Al-Ahsa, 31982, Saudi Arabia; Food Control Department, Faculty of Veterinary Medicine, Zagazig University, Zagazig, 44519, Egypt.
| | - Badr Abdul-Hakim Y Alahmad
- Department of Public Health, College of Veterinary Medicine, King Faisal University, P.O. Box: 400, Hofuf, Al-Ahsa, 31982, Saudi Arabia
| | - Ahmed M A Meligy
- Department of Clinical Science, Central Lab, College of Veterinary Medicine, King Faisal University, P.O. Box: 400, Hofuf, Al-Ahsa, 31982, Saudi Arabia; Department of Physiology, Agricultural Research Center (ARC), Giza, Egypt.
| | - Sherief M Abdel-Raheem
- Department of Public Health, College of Veterinary Medicine, King Faisal University, P.O. Box: 400, Hofuf, Al-Ahsa, 31982, Saudi Arabia; Department of Animal Nutrition and Clinical Nutrition, Faculty of Veterinary Medicine, Assiut University, 71526, Assiut, Egypt.
| | - Hesham Abdel-Moez Ahmed Ismail
- Department of Public Health, College of Veterinary Medicine, King Faisal University, P.O. Box: 400, Hofuf, Al-Ahsa, 31982, Saudi Arabia; Food Hygiene Dept., Fac. of Vet. Med., Assiut Univ., Egypt.
| | - Doaa Ibrahim
- Department of Nutrition and Clinical Nutrition, Faculty of Veterinary Medicine, Zagazig University, Zagazig, 44511, Egypt.
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Xing Q, Mesbah NM, Wang H, Li J, Zhao B. Quantitative evaluation of endogenous reference genes for ddPCR under salt stress using a moderate halophile. Extremophiles 2023; 27:8. [PMID: 36976376 DOI: 10.1007/s00792-023-01295-2] [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: 01/28/2023] [Accepted: 03/08/2023] [Indexed: 03/29/2023]
Abstract
Droplet digital PCR (ddPCR) is being increasingly adopted for gene detection and quantification because of its higher sensitivity and specificity. According to previous observations and our laboratory data, it is essential to use endogenous reference genes (RGs) when investigating gene expression at the mRNA level under salt stress. This study aimed to select and validate suitable RGs for gene expression under salt stress using ddPCR. Six candidate RGs were selected based on the tandem mass tag (TMT)-labeled quantitative proteomics of Alkalicoccus halolimnae at four salinities. The expression stability of these candidate genes was evaluated using statistical algorithms (geNorm, NormFinder, BestKeeper and RefFinder). There was a small fluctuation in the cycle threshold (Ct) value and copy number of the pdp gene. Its expression stability was ranked in the vanguard of all algorithms and was the most suitable RG for quantification of expression by both qPCR and ddPCR of A. halolimnae under salt stress. Single RG pdp and RG combinations were used to normalize the expression of ectA, ectB, ectC and ectD under four salinities. The present study constitutes the first systematic analysis of endogenous RG selection for halophiles responding to salt stress. This work provides a valuable theory and an approach reference of internal control identification for ddPCR-based stress response models.
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Affiliation(s)
- Qinghua Xing
- Graduate School, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Noha M Mesbah
- Faculty of Pharmacy, Suez Canal University, Ismailia, 41522, Egypt
| | - Haisheng Wang
- Graduate School, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Jun Li
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Baisuo Zhao
- Graduate School, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
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5
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Macedo R, Isidro J, Ferreira R, Pinto M, Borges V, Duarte S, Vieira L, Gomes JP. Molecular Capture of Mycobacterium tuberculosis Genomes Directly from Clinical Samples: A Potential Backup Approach for Epidemiological and Drug Susceptibility Inferences. Int J Mol Sci 2023; 24:ijms24032912. [PMID: 36769230 PMCID: PMC9918089 DOI: 10.3390/ijms24032912] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/20/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
The application of whole genome sequencing of Mycobacterium tuberculosis directly on clinical samples has been investigated as a means to avoid the time-consuming need for culture isolation that can lead to a potential prolonged suboptimal antibiotic treatment. We aimed to provide a proof-of-concept regarding the application of the molecular capture of M. tuberculosis genomes directly from positive sputum samples as an approach for epidemiological and drug susceptibility predictions. Smear-positive sputum samples (n = 100) were subjected to the SureSelectXT HS Target Enrichment protocol (Agilent Technologies, Santa Clara, CA, USA) and whole-genome sequencing analysis. A higher number of reads on target were obtained for higher smear grades samples (i.e., 3+ followed by 2+). Moreover, 37 out of 100 samples showed ≥90% of the reference genome covered with at least 10-fold depth of coverage (27, 9, and 1 samples were 3+, 2+, and 1+, respectively). Regarding drug-resistance/susceptibility prediction, for 42 samples, ≥90% of the >9000 hits that are surveyed by TB-profiler were detected. Our results demonstrated that M. tuberculosis genome capture and sequencing directly from clinical samples constitute a potential valid backup approach for phylogenetic inferences and resistance prediction, essentially in settings when culture is not routinely performed or for samples that fail to grow.
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Affiliation(s)
- Rita Macedo
- National Reference Laboratory for Mycobacteria, Department of Infectious Diseases, National Institute of Health (INSA), 1649-016 Lisbon, Portugal
| | - Joana Isidro
- Genomics and Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health (INSA), 1649-016 Lisbon, Portugal
| | - Rita Ferreira
- Genomics and Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health (INSA), 1649-016 Lisbon, Portugal
| | - Miguel Pinto
- Genomics and Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health (INSA), 1649-016 Lisbon, Portugal
| | - Vítor Borges
- Genomics and Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health (INSA), 1649-016 Lisbon, Portugal
| | - Sílvia Duarte
- Innovation and Technology Unit, National Institute of Health (INSA), 1649-016 Lisbon, Portugal
| | - Luís Vieira
- Innovation and Technology Unit, National Institute of Health (INSA), 1649-016 Lisbon, Portugal
| | - João Paulo Gomes
- Genomics and Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health (INSA), 1649-016 Lisbon, Portugal
- Correspondence:
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6
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Soto-Dávila M, Chakraborty S, Santander J. Relative expression and validation of Aeromonas salmonicida subsp. salmonicida reference genes during ex vivo and in vivo fish infection. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2022; 103:105320. [PMID: 35753622 DOI: 10.1016/j.meegid.2022.105320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 06/13/2022] [Accepted: 06/20/2022] [Indexed: 06/15/2023]
Abstract
The genus Aeromonas is found worldwide in freshwater and marine environments and has been implicated in the etiology of human and animal diseases. In fish, among Aeromonas species, A. salmonicida causes massive mortality and great economic losses in marine and continental aquaculture species. Currently, several aspects of the clinical signs and pathogenesis of this Gram-negative bacterium have been described; however, determination of an appropriate reference gene is essential to normalize cellular mRNA data remain unknown. Here we evaluate the stability of seven candidate reference genes to be used for data normalization during ex vivo and in vivo experiments conducted in Atlantic cod, Atlantic salmon, and lumpfish. To assess this, raw Ct values obtained were evaluated by using geNorm, NormFinder, BestKeeper, Delta Ct comparison, and the comprehensive ranking, through the bioinformatic open-access portal RefFinder. We determined that fabD and era were most suitable reference genes in Atlantic cod primary macrophages, hfq and era in Atlantic salmon primary macrophages, rpoB and fabD in lumpfish head kidney samples, and hfq and era in lumpfish spleen. Our study demonstrates that use of multiple reference genes and its validation before measurements helps to minimize variability arising in qPCR studies that evaluate A. salmonicida gene expression in fish tissues. Overall, this study provided with an expanded list of reliable reference genes for A. salmonicida gene expression using qPCR during fish infection studies.
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Affiliation(s)
- Manuel Soto-Dávila
- Marine Microbial Pathogenesis and Vaccinology Lab, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada; Department of Biology, Faculty of Science, University of Waterloo, Waterloo, ON, Canada
| | - Setu Chakraborty
- Marine Microbial Pathogenesis and Vaccinology Lab, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Javier Santander
- Marine Microbial Pathogenesis and Vaccinology Lab, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada.
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Nie M, Dong Y, Cao Q, Zhao D, Ji S, Huang H, Jiang M, Liu G, Liu Y. CRISPR Contributes to Adhesion, Invasion, and Biofilm Formation in Streptococcus agalactiae by Repressing Capsular Polysaccharide Production. Microbiol Spectr 2022; 10:e0211321. [PMID: 35861526 PMCID: PMC9430516 DOI: 10.1128/spectrum.02113-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 07/03/2022] [Indexed: 12/03/2022] Open
Abstract
The clustered regularly interspaced palindromic repeat (CRISPR)-associated (Cas) system functions classically as a prokaryotic defense system against invading mobile genetic elements, such as phages, plasmids, and viruses. Our previous study revealed that CRISPR deletion caused increased transcription of capsular polysaccharide (CPS) synthesis-related genes and severely attenuated virulence in the hypervirulent piscine Streptococcus agalactiae strain GD201008-001. Here, we found that CRISPR deficiency resulted in reduced adhesion, invasion, and biofilm formation abilities in this strain by upregulating the production of CPS. However, enhanced CPS production was not responsible for the attenuated phenotype of the ΔCRISPR mutant. RNA degradation assays indicated that inhibited transcription of the cps operon by CRISPR RNA (crRNA) was not due to the base pairing of the crRNA with the cps mRNA but to the repression of the promoter activity of cpsA, which is a putative transcriptional regulator of the capsule locus. IMPORTANCE Beyond protection from invading nucleic acids, CRISPR-Cas systems have been shown to have an important role in regulating bacterial endogenous genes. In this study, we demonstrate that crRNA inhibits the transcription of the cps operon by repressing the activity of promoter PcpsA, leading to increases in the abilities of adhesion, invasion, and biofilm formation in S. agalactiae. This study highlights the regulatory role of crRNA in bacterial physiology and provides a new explanation for the mechanism of crRNA-mediated endogenous gene regulation in S. agalactiae.
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Affiliation(s)
- Meng Nie
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Yuhao Dong
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Qing Cao
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Dan Zhao
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Shuting Ji
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Hao Huang
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Mingguo Jiang
- Guangxi Key Laboratory for Polysaccharide Materials and Modifications, School of Marine Sciences and Biotechnology, Guangxi University for Nationalities, Nanning, China
| | - Guangjin Liu
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Yongjie Liu
- Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China
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Du R, Gao D, Wang Y, Liu L, Cheng J, Liu J, Zhang XH, Yu M. Heterotrophic Sulfur Oxidation of Halomonas titanicae SOB56 and Its Habitat Adaptation to the Hydrothermal Environment. Front Microbiol 2022; 13:888833. [PMID: 35774465 PMCID: PMC9237845 DOI: 10.3389/fmicb.2022.888833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 05/24/2022] [Indexed: 11/23/2022] Open
Abstract
Halomonas bacteria are ubiquitous in global marine environments, however, their sulfur-oxidizing abilities and survival adaptations in hydrothermal environments are not well understood. In this study, we characterized the sulfur oxidation ability and metabolic mechanisms of Halomonas titanicae SOB56, which was isolated from the sediment of the Tangyin hydrothermal field in the Southern Okinawa Trough. Physiological characterizations showed that it is a heterotrophic sulfur-oxidizing bacterium that can oxidize thiosulfate to tetrathionate, with the Na2S2O3 degradation reaching 94.86%. Two potential thiosulfate dehydrogenase-related genes, tsdA and tsdB, were identified as encoding key catalytic enzymes, and their expression levels in strain SOB56 were significantly upregulated. Nine of fifteen examined Halomonas genomes possess TsdA- and TsdB-homologous proteins, whose amino acid sequences have two typical Cys-X2-Cys-His heme-binding regions. Moreover, the thiosulfate oxidation process in H. titanicae SOB56 might be regulated by quorum sensing, and autoinducer-2 synthesis protein LuxS was identified in its genome. Regarding the mechanisms underlying adaptation to hydrothermal environment, strain SOB56 was capable of forming biofilms and producing EPS. In addition, genes related to complete flagellum assembly system, various signal transduction histidine kinases, heavy metal transporters, anaerobic respiration, and variable osmotic stress regulation were also identified. Our results shed light on the potential functions of heterotrophic Halomonas bacteria in hydrothermal sulfur cycle and revealed possible adaptations for living at deep-sea hydrothermal fields by H. titanicae SOB56.
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Affiliation(s)
- Rui Du
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Di Gao
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China
| | - Yiting Wang
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China
| | - Lijun Liu
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China
| | - Jingguang Cheng
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China
| | - Jiwen Liu
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Xiao-Hua Zhang
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Min Yu
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology, Qingdao, China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
- *Correspondence: Min Yu,
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9
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Silvestre I, Nunes A, Borges V, Isidro J, Silva C, Vieira L, Gomes JP, Borrego MJ. Genomic insights on DNase production in Streptococcus agalactiae ST17 and ST19 strains. INFECTION GENETICS AND EVOLUTION 2021; 93:104969. [PMID: 34147652 DOI: 10.1016/j.meegid.2021.104969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 06/08/2021] [Accepted: 06/15/2021] [Indexed: 10/21/2022]
Abstract
Streptococcus agalactiae evasion from the human defense mechanisms has been linked to the production of DNases. These were proposed to contribute to the hypervirulence of S. agalactiae ST17/capsular-type III strains, mostly associated with neonatal meningitis. We performed a comparative genomic analysis between ST17 and ST19 human strains with different cell tropism and distinct DNase production phenotypes. All S. agalactiae ST17 strains, with the exception of 2211-04, were found to display DNase activity, while the opposite scenario was observed for ST19, where 1203-05 was the only DNase(+) strain. The analysis of the genetic variability of the seven genes putatively encoding secreted DNases in S. agalactiae revealed an exclusive amino acid change in the predicted signal peptide of GBS0661 (NucA) of the ST17 DNase(-), and an exclusive amino acid change alteration in GBS0609 of the ST19 DNase(+) strain. Further core-genome analysis identified some specificities (SNVs or indels) differentiating the DNase(-) ST17 2211-04 and the DNase(+) ST19 1203-05 from the remaining strains of each ST. The pan-genomic analysis evidenced an intact phage without homology in S. agalactiae and a transposon homologous to TnGBS2.3 in ST17 DNase(-) 2211-04; the transposon was also found in one ST17 DNase(+) strain, yet with a different site of insertion. A group of nine accessory genes were identified among all ST17 DNase(+) strains, including the Eco47II family restriction endonuclease and the C-5 cytosine-specific DNA methylase. None of these loci was found in any DNase(-) strain, which may suggest that these proteins might contribute to the lack of DNase activity. In summary, we provide novel insights on the genetic diversity between DNase(+) and DNase(-) strains, and identified genetic traits, namely specific mutations affecting predicted DNases (NucA and GBS0609) and differences in the accessory genome, that need further investigation as they may justify distinct DNase-related virulence phenotypes in S. agalactiae.
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Affiliation(s)
- Inês Silvestre
- Department of Life Sciences, UCIBIO, Nova School of Science and Technology, 2829-516 Caparica, Portugal; National Reference Laboratory for Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal
| | - Alexandra Nunes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal; CBIOS - Research Center for Biosciences & Health Technologies, Lusófona University of Humanities and Technologies, Campo Grande 376, 1749-024 Lisbon, Portugal
| | - Vítor Borges
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal
| | - Joana Isidro
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal
| | - Catarina Silva
- Innovation and Technology Unit, Department of Human Genetics, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal; Centre for Toxicogenomics and Human Health (ToxOmics), Nova Medical School
- Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, 1169-056 Lisbon, Portugal
| | - Luís Vieira
- Innovation and Technology Unit, Department of Human Genetics, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal; Centre for Toxicogenomics and Human Health (ToxOmics), Nova Medical School
- Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Campo dos Mártires da Pátria, 1169-056 Lisbon, Portugal
| | - João Paulo Gomes
- Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal.
| | - Maria José Borrego
- National Reference Laboratory for Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Avenida Padre Cruz, 1649-016 Lisbon, Portugal.
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10
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Liu G, Gao T, Yao H, Liu Y, Lu C. Transcriptional regulator XtgS is involved in iron transition and attenuates the virulence of Streptococcus agalactiae. Res Vet Sci 2021; 138:109-115. [PMID: 34126449 DOI: 10.1016/j.rvsc.2021.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 05/21/2021] [Accepted: 06/07/2021] [Indexed: 10/21/2022]
Abstract
Streptococcus agalactiae (GBS) is an important pathogen that has increasingly received attention for its role in invasive infections and its broad host range. Research on the regulation of gene expression could illuminate GBS pathogenesis. We previously identified a novel transcriptional regulator XtgS, which is a negative regulator of GBS pathogenicity. Here, we demonstrate that XtgS overexpression significantly attenuated GBS virulence in zebrafish infection tests, and XtgS indirectly downregulated the transcription of two iron transport systems based on the results of transcriptomic analysis, electrophoretic mobility shift assays (EMSAs) and lacZ fusion assays. Subsequent studies verified that the inactivation of iron transport system 1 resulted in GBS excessive iron accumulation and attenuated virulence. Thus, we infer that the downregulation of iron transport system 1 caused by XtgS overexpression probably attenuates bacterial virulence, which partially clarifies the mechanism by which XtgS alleviates the pathogenesis. These findings provide new insights into the relationship between exogenous transcriptional regulation and bacterial virulence.
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Affiliation(s)
- Guangjin Liu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China; OIE Reference Laboratory for Swine Streptococcosis, Nanjing, China; MOE Joint International Research Laboratory of Animal Health and Food Safety, Nanjing, China; Key Laboratory of Animal Bacteriology, Ministry of Agriculture, Nanjing, China.
| | - Tingting Gao
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China; OIE Reference Laboratory for Swine Streptococcosis, Nanjing, China; MOE Joint International Research Laboratory of Animal Health and Food Safety, Nanjing, China; Key Laboratory of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
| | - Huochun Yao
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China; OIE Reference Laboratory for Swine Streptococcosis, Nanjing, China; MOE Joint International Research Laboratory of Animal Health and Food Safety, Nanjing, China; Key Laboratory of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
| | - Yongjie Liu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China; OIE Reference Laboratory for Swine Streptococcosis, Nanjing, China; MOE Joint International Research Laboratory of Animal Health and Food Safety, Nanjing, China; Key Laboratory of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
| | - Chengping Lu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China; OIE Reference Laboratory for Swine Streptococcosis, Nanjing, China; MOE Joint International Research Laboratory of Animal Health and Food Safety, Nanjing, China; Key Laboratory of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
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11
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Pastuszka A, Beauruelle C, Camiade E, Rousseau GM, Moineau S, Mereghetti L, Horvath P, Lanotte P. Functional Study of the Type II-A CRISPR-Cas System of Streptococcus agalactiae Hypervirulent Strains. CRISPR J 2021; 4:233-242. [PMID: 33876956 DOI: 10.1089/crispr.2020.0145] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Nearly all strains of Streptococcus agalactiae, the leading cause of invasive infections in neonates, encode a type II-A clustered regularly interspaced short palindromic repeats (CRISPR)-Cas system. Interestingly, S. agalactiae strains belonging to the hypervirulent Sequence Type 17 (ST17) contain significantly fewer spacers in their CRISPR locus than other lineages, which could be the result of a less functional CRISPR-Cas system. Here, we revealed one large deletion in the ST17 cas promoter region and we evaluated its impact on the transcription of cas genes as well as the functionalities of the CRISPR-Cas system. We demonstrated that Cas9 interference is functional and that the CRISPR-Cas system of ST17 strains can still acquire new spacers, despite the absence of a regular cas promoter. We demonstrated that a promoter sequence upstream of srn036, a small RNA partially overlapping the antisense tracrRNA, is responsible for the ST17 CRISPR-Cas adaptation and interference activities.
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Affiliation(s)
- Adeline Pastuszka
- ISP, Université de Tours, INRAE, Tours, France; Dangé-Saint-Romain, France.,Service de Bactériologie-Virologie-Hygiène Hospitalière, CHRU de Tours, Tours, France; Dangé-Saint-Romain, France
| | - Clémence Beauruelle
- Département de Bactériologie-Virologie, Hygiène Hospitalière et Parasitologie-Mycologie, Centre Hospitalier Régional Universitaire (CHRU) de Brest, Brest, France; Dangé-Saint-Romain, France.,Univ Brest, Inserm, EFS, UMR 1078, GGB, Brest, France; Dangé-Saint-Romain, France
| | - Emilie Camiade
- ISP, Université de Tours, INRAE, Tours, France; Dangé-Saint-Romain, France
| | - Geneviève M Rousseau
- Département de Biochimie, de Microbiologie, et de Bio-informatique, Faculté des Sciences et de Génie, Groupe de Recherche en Écologie Buccale, Faculté de Médecine Dentaire, Université Laval, Québec City, Canada; Dangé-Saint-Romain, France
| | - Sylvain Moineau
- Département de Biochimie, de Microbiologie, et de Bio-informatique, Faculté des Sciences et de Génie, Groupe de Recherche en Écologie Buccale, Faculté de Médecine Dentaire, Université Laval, Québec City, Canada; Dangé-Saint-Romain, France.,Félix d'Hérelle Reference Center for Bacterial Viruses, Université Laval, Québec City, Canada; and Dangé-Saint-Romain, France
| | - Laurent Mereghetti
- ISP, Université de Tours, INRAE, Tours, France; Dangé-Saint-Romain, France.,Service de Bactériologie-Virologie-Hygiène Hospitalière, CHRU de Tours, Tours, France; Dangé-Saint-Romain, France
| | | | - Philippe Lanotte
- ISP, Université de Tours, INRAE, Tours, France; Dangé-Saint-Romain, France.,Service de Bactériologie-Virologie-Hygiène Hospitalière, CHRU de Tours, Tours, France; Dangé-Saint-Romain, France
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12
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Dammann AN, Chamby AB, Catomeris AJ, Davidson KM, Tettelin H, van Pijkeren JP, Gopalakrishna KP, Keith MF, Elder JL, Ratner AJ, Hooven TA. Genome-Wide fitness analysis of group B Streptococcus in human amniotic fluid reveals a transcription factor that controls multiple virulence traits. PLoS Pathog 2021; 17:e1009116. [PMID: 33684178 PMCID: PMC7971860 DOI: 10.1371/journal.ppat.1009116] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 03/18/2021] [Accepted: 02/18/2021] [Indexed: 02/06/2023] Open
Abstract
Streptococcus agalactiae (group B Streptococcus; GBS) remains a dominant cause of serious neonatal infections. One aspect of GBS that renders it particularly virulent during the perinatal period is its ability to invade the chorioamniotic membranes and persist in amniotic fluid, which is nutritionally deplete and rich in fetal immunologic factors such as antimicrobial peptides. We used next-generation sequencing of transposon-genome junctions (Tn-seq) to identify five GBS genes that promote survival in the presence of human amniotic fluid. We confirmed our Tn-seq findings using a novel CRISPR inhibition (CRISPRi) gene expression knockdown system. This analysis showed that one gene, which encodes a GntR-class transcription factor that we named MrvR, conferred a significant fitness benefit to GBS in amniotic fluid. We generated an isogenic targeted deletion of the mrvR gene, which had a growth defect in amniotic fluid relative to the wild type parent strain. The mrvR deletion strain also showed a significant biofilm defect in vitro. Subsequent in vivo studies showed that while the mutant was able to cause persistent murine vaginal colonization, pregnant mice colonized with the mrvR deletion strain did not develop preterm labor despite consistent GBS invasion of the uterus and the fetoplacental units. In contrast, pregnant mice colonized with wild type GBS consistently deliver prematurely. In a sepsis model the mrvR deletion strain showed significantly decreased lethality. In order to better understand the mechanism by which this newly identified transcription factor controls GBS virulence, we performed RNA-seq on wild type and mrvR deletion GBS strains, which revealed that the transcription factor affects expression of a wide range of genes across the GBS chromosome. Nucleotide biosynthesis and salvage pathways were highly represented among the set of differentially expressed genes, suggesting that MrvR may be involved in regulating nucleotide availability. Group B Streptococcus (GBS) is a species of Gram-positive bacteria that often colonizes the healthy adult intestinal and reproductive tracts without causing serious symptoms. During pregnancy, however, GBS can invade the pregnant uterus, where it can cause infection of the placenta, fetal membranes, and fetus—a condition known as chorioamnionitis. Chorioamnionitis is associated with serious adverse pregnancy outcomes, including stillbirth, preterm labor, and severe infection of the newborn. GBS can survive in human amniotic fluid, which is low in bacterial nutrients and contains immune molecules that limit microbial persistence, and this ability likely contributes to GBS chorioamnionitis. This study is focused on a single GBS gene that encodes a genetic regulator we called MrvR, which we show is important for GBS resistance to human amniotic fluid. Using a series of genetic techniques combined with animal models of GBS colonization and infection, we show that MrvR also plays a key role in allowing GBS to invade the bloodstream and trigger the inflammatory responses that lead to preterm labor and stillbirth. The study concludes with a survey of other GBS genes whose activity is regulated by MrvR, which seems to be an important contributor to GBS virulence.
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Affiliation(s)
- Allison N. Dammann
- Department of Pediatrics, New York University School of Medicine, New York, New York, United States of America
| | - Anna B. Chamby
- University of Vermont Larner College of Medicine, Burlington, Vermont, United States of America
| | - Andrew J. Catomeris
- Georgetown University School of Medicine, Washington, District of Columbia, United States of America
| | - Kyle M. Davidson
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Hervé Tettelin
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Jan-Peter van Pijkeren
- Department of Food Science, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Kathyayini P. Gopalakrishna
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Mary F. Keith
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Jordan L. Elder
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Adam J. Ratner
- Department of Pediatrics, New York University School of Medicine, New York, New York, United States of America
- Department of Microbiology, New York University, New York, New York, United States of America
| | - Thomas A. Hooven
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- Richard King Mellon Institute for Pediatric Research, UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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13
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Liu X, Zhang Y, Huang K, Yin T, Li Q, Zou Q, Guo D, Zhang X. rpoB and efp are stable candidate reference genes for quantitative real-time PCR analysis in Saccharopolyspora spinosa. BIOTECHNOL BIOTEC EQ 2021. [DOI: 10.1080/13102818.2021.1899852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- Xiaomeng Liu
- Beijing Key Laboratory of Nutrition & Health and Food Safety, Nutrition and Health Research Institute, COFCO, Beijing, PR China
| | - Yunpeng Zhang
- Beijing Key Laboratory of Nutrition & Health and Food Safety, Nutrition and Health Research Institute, COFCO, Beijing, PR China
| | - Kexue Huang
- Qilu Pharmaceutical (Inner Mongolia) Co., Ltd, Hohhot, Inner Mongolia, PR China
| | - Tie Yin
- Beijing Key Laboratory of Nutrition & Health and Food Safety, Nutrition and Health Research Institute, COFCO, Beijing, PR China
| | - Qi Li
- Beijing Key Laboratory of Nutrition & Health and Food Safety, Nutrition and Health Research Institute, COFCO, Beijing, PR China
| | - Qiulong Zou
- Beijing Key Laboratory of Nutrition & Health and Food Safety, Nutrition and Health Research Institute, COFCO, Beijing, PR China
| | - Dongsheng Guo
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, Jiangsu Province, PR China
| | - Xiaolin Zhang
- Beijing Key Laboratory of Nutrition & Health and Food Safety, Nutrition and Health Research Institute, COFCO, Beijing, PR China
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, Jiangsu Province, PR China
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14
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Pieranski M, Sitkiewicz I, Grinholc M. Increased photoinactivation stress tolerance of Streptococcus agalactiae upon consecutive sublethal phototreatments. Free Radic Biol Med 2020; 160:657-669. [PMID: 32916279 DOI: 10.1016/j.freeradbiomed.2020.09.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/24/2020] [Accepted: 09/02/2020] [Indexed: 02/08/2023]
Abstract
Streptococcus agalactiae (Group B Streptococcus, GBS) is a common commensal bacterium in adults but remains a leading source of invasive infections in newborns, pregnant women, and the elderly, and more recently, causes an increased incidence of invasive disease in nonpregnant adults. Reduced penicillin susceptibility and emerging resistance to non-β-lactams pose challenges for the development and implementation of novel, nonantimicrobial strategies to reduce the burden of GBS infections. Antimicrobial photodynamic inactivation (aPDI) via the production of singlet oxygen or other reactive oxygen species leads to the successful eradication of pathogenic bacteria, affecting numerous cellular targets of microbial pathogens and indicating a low risk of resistance development. Nevertheless, we have previously reported possible aPDI tolerance development upon repeated sublethal aPDI applications; thus, the current work was aimed at investigating whether aPDI tolerance could be observed for GBS and what mechanisms could cause it. To address this problem, 10 cycles of sublethal aPDI treatments employing rose bengal as a photosensitizer, were applied to the S. agalactiae ATCC 27956 reference strain and two clinical isolates (2306/02 and 2974/07, serotypes III and V, respectively). We demonstrated aPDI tolerance development and stability after 5 cycles of subculturing with no aPDI exposure. Though the treatment resulted in a stable phenotype, no increases in mutation rate or accumulated genetic alterations were observed (employing a RIF-, CIP-, STR-resistant mutant selection assay and cyl sequencing, respectively). qRT-PCR analysis demonstrated that 10 sublethal aPDI exposures led to increased expression of all tested major oxidative stress response elements; changes in sodA, ahpC, npx, cylE, tpx and recA expression indicate possible mechanisms of developed tolerance. Increased expression upon sublethal aPDI treatment was reported for all but two genes, namely, ahpC and cylE. aPDI targeting cylE was further supported by colony morphology changes induced with 10 cycles of aPDI (increased SCV population, increased hemolysis, increased numbers of dark- and unpigmented colonies). In oxidant killing assays, aPDI-tolerant strains demonstrated no increased tolerance to hypochlorite, superoxide (paraquat), singlet oxygen (new methylene blue) or oxidative stress induced by aPDI employing a structurally different photosensitizer, i.e., zinc phthalocyanine, indicating a lack of cross resistance. The results indicate that S. agalactiae may develop stable aPDI tolerance but not resistance when subjected to multiple sublethal phototreatments, and this risk should be considered significant when defining efficient anti-S. agalactiae aPDI protocols.
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Affiliation(s)
- Michal Pieranski
- Intercollegiate Faculty of Biotechnology, Laboratory of Molecular Diagnostics, University of Gdansk and Medical University of Gdansk, Abrahama 58, 80-307, Gdansk, Poland
| | - Izabela Sitkiewicz
- Department of Drug Biotechnology and Bioinformatics, National Medicines Institute, Chelmska 30/34, 00-725, Warszawa, Poland
| | - Mariusz Grinholc
- Intercollegiate Faculty of Biotechnology, Laboratory of Molecular Diagnostics, University of Gdansk and Medical University of Gdansk, Abrahama 58, 80-307, Gdansk, Poland.
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15
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Validation of stable reference genes in Staphylococcus aureus to study gene expression under photodynamic treatment: a case study of SEB virulence factor analysis. Sci Rep 2020; 10:16354. [PMID: 33004977 PMCID: PMC7530716 DOI: 10.1038/s41598-020-73409-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 09/14/2020] [Indexed: 12/27/2022] Open
Abstract
Staphylococcal enterotoxin B (SEB), encoded by the seb gene, is a virulence factor produced by Staphylococcus aureus that is involved mainly in food poisoning and is known to act as an aggravating factor in patients with atopic dermatitis. Research results in animal infection models support the concept that superantigens, including SEB contribute to sepsis and skin and soft tissue infections. In contrast to antibiotics, antimicrobial photodynamic inactivation (aPDI) is a promising method to combat both bacterial cells and virulence factors. The main aims of this research were to (1) select the most stable reference genes under sublethal aPDI treatments and (2) evaluate the impact of aPDI on seb. Two aPDI combinations were applied under sublethal conditions: rose bengal (RB) and green light (λmax = 515 nm) and new methylene blue (NMB) and red light (λmax = 632 nm). The stability of ten candidate reference genes (16S rRNA, fabD, ftsZ, gmk, gyrB, proC, pyk, rho, rpoB and tpiA) was evaluated upon aPDI using four software packages—BestKeeper, geNorm, NormFinder and RefFinder. Statistical analyses ranked ftsZ and gmk (RB + green light) and ftsZ, proC, and fabD (NMB + red light) as the most stable reference genes upon photodynamic treatment. Our studies showed downregulation of seb under both aPDI conditions, suggesting that aPDI could decrease the level of virulence factors.
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16
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The Novel Streptococcal Transcriptional Regulator XtgS Negatively Regulates Bacterial Virulence and Directly Represses PseP Transcription. Infect Immun 2020; 88:IAI.00035-20. [PMID: 32690636 DOI: 10.1128/iai.00035-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 07/04/2020] [Indexed: 01/14/2023] Open
Abstract
Streptococcus agalactiae (group B streptococcus [GBS]) has received continuous attention for its involvement in invasive infections and its broad host range. Transcriptional regulators have an important impact on bacterial adaptation to various environments. Research on transcriptional regulators will shed new light on GBS pathogenesis. In this study, we identified a novel XRE-family transcriptional regulator encoded on the GBS genome, designated XtgS. Our data demonstrate that XtgS inactivation significantly increases bacterial survival in host blood and animal challenge test, suggesting that it is a negative regulator of GBS pathogenicity. Further transcriptomic analysis and quantitative reverse transcription-PCR (qRT-PCR) mainly indicated that XtgS significantly repressed transcription of its upstream gene pseP Based on electrophoretic mobility shift and lacZ fusion assays, we found that an XtgS homodimer directly binds a palindromic sequence in the pseP promoter region. Meanwhile, the PseP and XtgS combination naturally coexists in diverse Streptococcus genomes and has a strong association with sequence type, serotype diversification and host adaptation of GBS. Therefore, this study reveals that XtgS functions as a transcriptional regulator that negatively affects GBS virulence and directly represses PseP expression, and it provides new insights into the relationships between transcriptional regulator and genome evolution.
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17
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Arginine Deiminase and Biotin Metabolism Signaling Pathways Play an Important Role in Human-Derived Serotype V, ST1 Streptococcus agalactiae Virulent Strain upon Infected Tilapia. Animals (Basel) 2020; 10:ani10050849. [PMID: 32423070 PMCID: PMC7278441 DOI: 10.3390/ani10050849] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 04/14/2020] [Accepted: 04/15/2020] [Indexed: 01/18/2023] Open
Abstract
Simple Summary Patients who were infected with Streptococcus agalactiae (ST1) were mainly associated with asymptomatic carriage. However, the invasive diseases in non-pregnant adults caused by S. agalactiae (serotype V, ST1) have increased recently. We have previously reported that human-derived S. agalactiae (serotype V, ST1) could infect tilapia with virulence and pathologic characteristics similar to highly virulent tilapia-derived S. agalactiae (ST7) strains. The potential risk of cross-species infection cannot be ignored. Therefore, our research provided a multi-omics analysis of the human-derived serotype V ST1 S. agalactiae strains, which were virulent and non-virulent to tilapia and provided a more comprehensive understanding of the virulence mechanism. Abstract Our previous study showed that human-derived Streptococcus agalactiae (serotype V) could infect tilapia, but the mechanism underlying the cross-species infection remains unrecognized. In this study, a multi-omics analysis was performed on human-derived S. agalactiae strain NNA048 (virulent to tilapia, serotype V, ST1) and human-derived S. agalactiae strain NNA038 (non-virulent to tilapia, serotype V, ST1). The results showed that 907 genes (504 up/403 down) and 89 proteins (51 up/38 down) were differentially expressed (p < 0.05) between NNA038 and NNA048. Among them, 56 genes (proteins) were altered with similar trends at both mRNA and protein levels. Functional annotation of them showed that the main differences were enriched in the arginine deiminase system signaling pathway and biotin metabolism signaling pathway: gdhA, glnA, ASL, ADI, OTC, arcC, FabF, FabG, FabZ, BioB and BirA genes may have been important factors leading to the pathogenicity differences between NNA038 and NNA048. We aimed to provide a comprehensive analysis of the human-derived serotype V ST1 S. agalactiae strains, which were virulent and non-virulent to tilapia, and provide a more comprehensive understanding of the virulence mechanism.
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18
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Zhang Z, Li Y, Hu M, Yu A. Comparative transcriptome profiling reveals a mechanism of Streptococcus agalactiae resistance to florfenicol. Microb Pathog 2020; 142:104098. [PMID: 32109567 DOI: 10.1016/j.micpath.2020.104098] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 02/19/2020] [Accepted: 02/22/2020] [Indexed: 11/18/2022]
Abstract
Florfenicol is widely used to control diseases in aquatic animals, and is used extensively to treat streptococcosis-caused by Streptococcus agalactiae-in the commercially important fish tilapia. There are known issues with the development of florfenicol resistance in Streptococcus agalactiae, but the underlying resistance mechanisms are not clear, a situation currently preventing optimal deployment of antibiotics. Here, we examined the induction of resistance by successively increasing the concentrations of florfenicol, and then used RNA-sequencing (RNA-Seq) to characterize changes in the transcriptomes of a florfenicol-resistant strain (H51-R) and a florfenicol-sensitive strain (H51-S). We obtained a total of 18,418,068 sequence reads in H51-R and 16,070,122 sequence reads in H51-S, from which a total of 1940 unigenes were assembled. In total, 376 unigenes were found to be differently expressed genes (DEGs). After florfenicol treatment, 181 genes were upregulated and 195 genes were downregulated. GO functional analysis of the DEGs indicated that the most strongly enriched GO terms included metabolic process (152 genes), catalytic activity (146), and binding (133), with terms including membrane, membrane part, and transporter activity also showing enrichment. KEGG pathway enrichment analysis highlighted that ribosomes were prominently involved in the transcriptional changes associated with florfenicol resistance. This study demonstrates that florfenicol treatment affects multiple biological functions of Streptococcus agalactiae, suggests that florfenicol resistance in Streptococcus agalactiae is closely related to the reduction of intracellular drug accumulation caused by ATP-binding cassette (ABC) transporters, and highlights the potential involvement of altered ribosomal function in florfenicol resistance.
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Affiliation(s)
- Ze Zhang
- College of Life Sciences, Beijing Normal University, Beijing, 100875, China; National Institute of Biological Sciences, Zhongguancun Life Science Park, Changping, 102206, Beijing, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, 102206, Beijing, China.
| | - Yuhui Li
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Minqiang Hu
- School of Chemical Biology and Biotechnology, Shenzhen Graduate School, Peking University, Shenzhen, 518055, China
| | - Angen Yu
- Department of Aquatic Animal Medicine, Research Center for Marine Biology, College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
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19
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Liu Y, Li L, Huang T, Wu W, Liang W, Chen M. The Interaction between Phagocytes and Streptococcus agalactiae (GBS) Mediated by the Activated Complement System is the Key to GBS Inducing Acute Bacterial Meningitis of Tilapia. Animals (Basel) 2019; 9:ani9100818. [PMID: 31623233 PMCID: PMC6826838 DOI: 10.3390/ani9100818] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 10/02/2019] [Accepted: 10/10/2019] [Indexed: 12/14/2022] Open
Abstract
Simple Summary Streptococcus agalactiae (GBS) is a serious threat to farmed tilapia, which results in high mortality and seriously hinders tilapia farming development. The pathogenic mechanism of tilapia infected with GBS which die rapidly in production remains unknown. We provided a comprehensive comparative analysis of the tilapias infected with fish-derived GBS attenuated strain YM001 and its parental virulent strain HN016. The present study indicates that the interaction between phagocytes and GBS mediated by the activated complement system is key to GBS inducing tilapia acute bacterial meningitis. The low survival ability caused by reduced β-lactam antibiotics resistance is one of the important reasons YM001 lost its pathogenicity to tilapia. Our study provided a comprehensive cognition of the mechanism of acute bacterial meningitis caused by GBS. Abstract Streptococcus agalactiae is an important pathogen for tilapia meningitis. Most of the infected tilapia die rapidly in production, when the way to study the pathogenic mechanism of bacteria on host through chronic infection in laboratory is not comprehensive and accurate enough to elucidate the real pathogenic mechanism. The objective of this study was to investigate the mechanism of acute bacterial meningitis of tilapia caused by Streptococcus agalactiae (GBS), and provide a theoretical basis for its prevention and treatment. Duel RNA-seq, proteome analysis, histopathological analysis, plasma biochemical indexes, and blood routine examination were performed on tilapias infected with fish-derived GBS attenuated strain YM001 and its parental virulent strain HN016. The results showed that the contents of white blood cell (WBC), monocytes (MON), and neutrophil (NEU) were significantly lower in the HN016 group compared to that in the YM001 group (p < 0.05). Histopathological examination showed that there were partially lesions in the examined tissues of tilapia infected by HN016, while no obvious histopathological changes occurred in the YM001 group. The differential expressed genes (DEGs) and differential expressed proteins (DEPs) between YM001 and HN016 were mainly enriched in the beta-lactam resistance pathway (oppA1, oppA2, oppB, oppC, oppD, oppF, and mrcA). The DEGs DEPs between YM001-brain and HN016-brain were mainly enriched in the complement and coagulation cascades signaling pathway (C2a, c4b, c3b, c7, CD59, ITGB2, and ITGAX). The present study indicates that the interaction between phagocytes and GBS mediated by the activated complement system is the key to GBS inducing tilapia acute bacterial meningitis. The low survival ability caused by reduced β-lactam antibiotics resistance is one of the important reasons for why YM001 lost its pathogenicity to tilapia.
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Affiliation(s)
- Yu Liu
- Guangxi Academy of Fishery Sciences, Fish diseases control and prevention lab, Qingshan Road NO.8, Nanning 530021, China.
| | - Liping Li
- Guangxi Academy of Fishery Sciences, Fish diseases control and prevention lab, Qingshan Road NO.8, Nanning 530021, China.
| | - Ting Huang
- Guangxi Academy of Fishery Sciences, Fish diseases control and prevention lab, Qingshan Road NO.8, Nanning 530021, China.
| | - Wende Wu
- Guangxi University, Daxuedong Road NO.100, Nanning 530004, China.
| | - Wanwen Liang
- Guangxi Academy of Fishery Sciences, Fish diseases control and prevention lab, Qingshan Road NO.8, Nanning 530021, China.
| | - Ming Chen
- Guangxi Academy of Fishery Sciences, Fish diseases control and prevention lab, Qingshan Road NO.8, Nanning 530021, China.
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Li L, Liu Y, Huang T, Liang W, Chen M. Development of an attenuated oral vaccine strain of tilapia Group B Streptococci serotype Ia by gene knockout technology. FISH & SHELLFISH IMMUNOLOGY 2019; 93:924-933. [PMID: 31374315 DOI: 10.1016/j.fsi.2019.07.081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 07/26/2019] [Accepted: 07/29/2019] [Indexed: 06/10/2023]
Abstract
Our previous studies demonstrated that the deletion of D2 fragment in tilapia Streptococcus agalactiae(GBS) attenuated strain YM001 is the main reason for the loss of virulence to tilapia. In this study, a Δ2 mutant that deletion of D2 fragment in parental virulent strain HN016 was constructed, and the safety, stability, immunogenicity, and growth characteristics, as well as the virulence mechanism of Δ2 mutant were evaluated. The results showed that Δ2 mutant was not pathogenic to tilapia, and the virulent revertants were not observed after 50 generations of passage. The RPS reached 96.11% at 15 days and 93.05% at 30 days, respectively, after intraperitoneal injection, while RPS reached 74.80% at 15 days and 53.16% at 30 days, respectively, after oral immunization. The growth of Δ2 mutant was significantly faster than YM001, and genes that were enriched in the nitrogen metabolism and arginine biosynthesis signaling pathway (arc, glnA, and gdhA) were identified as important candidate genes responsible for growth rate of S. agalactiae. The absence of D2 fragment affected the expression of Sip, therefore influencing the bacterial virulence. Altogether, this study demonstrated that deletion of D2 fragment in HN016 causes the loss of virulence to tilapia, and Δ2 mutant is a promising, better attenuated oral vaccine strain of S. agalactiae compared to YM001.
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Affiliation(s)
- Liping Li
- Guangxi Academy of Fishery Sciences, Qingshan Road NO.8, Nanning, 530021, China
| | - Yu Liu
- Guangxi Academy of Fishery Sciences, Qingshan Road NO.8, Nanning, 530021, China
| | - Ting Huang
- Guangxi Academy of Fishery Sciences, Qingshan Road NO.8, Nanning, 530021, China
| | - Wanwen Liang
- Guangxi Academy of Fishery Sciences, Qingshan Road NO.8, Nanning, 530021, China
| | - Ming Chen
- Guangxi Academy of Fishery Sciences, Qingshan Road NO.8, Nanning, 530021, China.
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Glutathione Synthesis Contributes to Virulence of Streptococcus agalactiae in a Murine Model of Sepsis. J Bacteriol 2019; 201:JB.00367-19. [PMID: 31331978 DOI: 10.1128/jb.00367-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 07/10/2019] [Indexed: 01/09/2023] Open
Abstract
Streptococcus agalactiae, a leading cause of sepsis and meningitis in neonates, utilizes multiple virulence factors to survive and thrive within the human host during an infection. Unique among the pathogenic streptococci, S. agalactiae uses a bifunctional enzyme encoded by a single gene (gshAB) to synthesize glutathione (GSH), a major antioxidant in most aerobic organisms. Since S. agalactiae can also import GSH, similar to all other pathogenic streptococcal species, the contribution of GSH synthesis to the pathogenesis of S. agalactiae disease is not known. In the present study, gshAB deletion mutants were generated in strains representing three of the most prevalent clinical serotypes of S. agalactiae and were compared against isogenic wild-type and gshAB knock-in strains. When cultured in vitro in a chemically defined medium under nonstress conditions, each mutant and its corresponding wild type had comparable growth rates, generation times, and growth yields. However, gshAB deletion mutants were found to be more sensitive than wild-type or gshAB knock-in strains to killing and growth inhibition by several different reactive oxygen species. Furthermore, deletion of gshAB in S. agalactiae strain COH1 significantly attenuated virulence compared to the wild-type or gshAB knock-in strains in a mouse model of sepsis. Taken together, these data establish that GSH is a virulence factor important for resistance to oxidative stress and that de novo GSH synthesis plays a crucial role in S. agalactiae pathogenesis and further suggest that the inhibition of GSH synthesis may provide an opportunity for the development of novel therapies targeting S. agalactiae disease.IMPORTANCE Approximately 10 to 30% of women are naturally and asymptomatically colonized by Streptococcus agalactiae However, transmission of S. agalactiae from mother to newborn during vaginal birth is a leading cause of neonatal meningitis. Although colonized mothers who are at risk for transmission to the newborn are treated with antibiotics prior to delivery, S. agalactiae is becoming increasingly resistant to current antibiotic therapies, and new treatments are needed. This research reveals a critical stress resistance pathway, glutathione synthesis, that is utilized by S. agalactiae and contributes to its pathogenesis. Understanding the role of this unique bifunctional glutathione synthesis enzyme in S. agalactiae during sepsis may help elucidate why S. agalactiae produces such an abundance of glutathione compared to other bacteria.
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Selection of reference genes for measuring the expression of aiiO in Ochrobactrum quorumnocens A44 using RT-qPCR. Sci Rep 2019; 9:13129. [PMID: 31511547 PMCID: PMC6739375 DOI: 10.1038/s41598-019-49474-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 08/22/2019] [Indexed: 11/09/2022] Open
Abstract
Reverse transcription quantitative PCR (RT-qPCR), a method of choice for quantification of gene expression changes, requires stably expressed reference genes for normalization of data. So far, no reference genes were established for the Alphaproteobacteria of the genus Ochrobactrum. Here, we determined reference genes for gene expression studies in O. quorumnocens A44. Strain A44 was cultured under 10 different conditions and the stability of expression of 11 candidate genes was evaluated using geNorm, NormFinder and BestKeeper. Most stably expressed genes were found to be rho, gyrB and rpoD. Our results can facilitate the choice of reference genes in the related Ochrobactrum strains. O. quorumnocens A44 is able to inactivate a broad spectrum of N-acyl homoserine lactones (AHLs) - the quorum sensing molecules of many Gram-negative bacteria. This activity is attributed to AiiO hydrolase, yet it remains unclear whether AHLs are the primary substrate of this enzyme. Using the established RT-qPCR setup, we found that the expression of the aiiO gene upon exposure to two AHLs, C6-HLS and 3OC12-HSL, does not change above the 1-fold significance threshold. The implications of this finding are discussed in the light of the role of quorum sensing-interfering enzymes in the host strains.
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Wang X, Peng F, Dong G, Sun Y, Dai X, Yang Y, Liu X, Bai Z. Identification and validation of appropriate reference genes for qRT-PCR analysis in Corynebacterium glutamicum. FEMS Microbiol Lett 2019; 365:4840241. [PMID: 29420726 DOI: 10.1093/femsle/fny030] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Accepted: 02/05/2018] [Indexed: 12/30/2022] Open
Abstract
Real-time quantitative PCR (qRT-PCR) is a fast and efficient technology for detecting gene expression levels in the study of the Corynebacterium glutamicum protein expression system, but it requires normalization to ensure the reliability of the results obtained. We selected 13 genes from the commonly used housekeeping genes and from transcriptome data as candidate reference genes. The Ct values of the 13 genes were obtained by qRT-PCR at different fermentation stages and under three stress conditions (temperature, acid and salt). The expression stability of the reference genes was evaluated by geNorm and NormFinder software. For the study of different growth stages, the most appropriate reference genes are Ncgl2772 and leua, which encode acetyl-CoA carboxylase beta subunit and 2-isopropylmalate synthase, separately. For the study of different stress factors, the optimal minimum number of reference genes is 3, with Ncgl2772, gyrb encoding DNA gyrase B and siga encoding RNA polymerase sigma factor A as the most suitable combination. Additionally, clpx and clpc, encoding ClpX and ClpC protease subunits, were used to validate the candidate reference genes. The identification of new reference genes makes qRT-PCR more convenient, and using these genes for normalization can improve the accuracy and reliability of the measurements of target gene expression levels obtained by qRT-PCR for C. glutamicum.
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Affiliation(s)
- XinYue Wang
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Feng Peng
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Guibin Dong
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Yang Sun
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Xiaofeng Dai
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Yankun Yang
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Xiuxia Liu
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Zhonghu Bai
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China.,The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
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Liu Y, Li L, Huang T, Wang R, Liang W, Yang Q, Lei A, Chen M. Comparative multi-omics systems analysis reveal the glycolysis / gluconeogenesis signal pathway play an important role in virulence attenuation in fish-derived GBS YM001. PLoS One 2019; 14:e0221634. [PMID: 31449567 PMCID: PMC6709914 DOI: 10.1371/journal.pone.0221634] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 08/12/2019] [Indexed: 01/18/2023] Open
Abstract
Streptococcus agalactiae(GBS) is a seriously threat to the farmed tilapia, and oral vaccination was considered to be the most desirable means which requires deep understanding of virulence mechanism of the fish-derived GBS. Our previous genome study of the fish-derived attenuated strain YM001 showed that there were two large deletions in YM001 compared to its parental virulent strain HN016. In this study, a combined transcriptomic and proteomic analysis was performed on YM001 and HN016 strains, and the important genes were verified by RT-qPCR in bacteria strains and infected-tilapia tissues. Overall, we have shown that a total of 958 genes and 331 proteins were significantly differential expressed between YM001 and HN016. By functional annotation of these DEGs and DEPs, genes that were enriched in pentose phosphate pathway(pgm, ptsG, pgi pfkA, fbaA and FBP3) and pyruvate metabolism pathway(pdhA, pdhB, pdhC and pdhD) were identifed as important candidate genes for leads low growth ability in attenuated strain, which may be an important reasons leading virulence attenuation in the end. The expression levels the candidate genes in pentose phosphate pathway and pyruvate metabolism pathway were significant differential expressed in tilapia’ brain and spleen when infected with YM001 and HN016. Our study indicated that the pentose phosphate pathway and pyruvate metabolism pathway that affecting the growth of the strain may be one of the important reasons for the virulence attenuation in HN016.
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Affiliation(s)
- Yu Liu
- Guangxi Academy of Fishery Sciences, Nanning,China,P.R. China
| | - Liping Li
- Guangxi Academy of Fishery Sciences, Nanning,China,P.R. China
| | - Ting Huang
- Guangxi Academy of Fishery Sciences, Nanning,China,P.R. China
| | - Rui Wang
- Guangxi Academy of Fishery Sciences, Nanning,China,P.R. China
| | - Wanwen Liang
- Guangxi Academy of Fishery Sciences, Nanning,China,P.R. China
| | - Qiong Yang
- Guangxi Academy of Fishery Sciences, Nanning,China,P.R. China
| | - Aiying Lei
- Guangxi Academy of Fishery Sciences, Nanning,China,P.R. China
| | - Ming Chen
- Guangxi Academy of Fishery Sciences, Nanning,China,P.R. China
- * E-mail:
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mRNA extraction of Xanthomonas fragariae in strawberry and validation of reference genes for the RT-qPCR for study of bacterial gene expression. Mol Biol Rep 2019; 46:5723-5733. [PMID: 31368022 DOI: 10.1007/s11033-019-05006-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 07/26/2019] [Indexed: 01/11/2023]
Abstract
This is the first study which describes a unique procedure of isolating of high-quality, intact RNA from strawberry leaves of Xanthomonas fragariae, three most suitable reference genes, crucial for the normalization of RT-qPCR data for this pathogen and accurate expression analysis of target genes. In our study, various mathematic algorithms: NormFinder geNorm, BestKeeper, the delta CT method, RefFinder were adopted for validation of most stable reference genes from nine candidate genes (ffh, glyA, gyrA, gyrB, proC, pykA, recA, rpoB, rpoD). The analyses allowing to select three most suitable pioneer reference genes, gyrB, ffh, and pykA, that we recommend for the normalization of RT-qPCR data and for the study of the expression of target genes in Xf. Moreover, their combination as references allowed for an accurate expression analysis and computation of the fold change of the flhF and iroN2 genes in Xf. These two genes are important for the success of the colonization of plant tissue and pathogenicity and sequences of primers designed to study these genes, are presented.
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Reference genes for real-time RT-PCR expression studies in an Antarctic Pseudomonas exposed to different temperature conditions. Extremophiles 2019; 23:625-633. [DOI: 10.1007/s00792-019-01109-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 06/17/2019] [Indexed: 12/21/2022]
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Fang L, Shi T, Chen Y, Wu X, Zhang C, Tang X, Li QX, Hua R. Kinetics and Catabolic Pathways of the Insecticide Chlorpyrifos, Annotation of the Degradation Genes, and Characterization of Enzymes TcpA and Fre in Cupriavidus nantongensis X1 T. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:2245-2254. [PMID: 30721044 DOI: 10.1021/acs.jafc.9b00173] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Chlorpyrifos is one of the most used organophosphorus insecticides. It is commonly degraded to 3,5,6-trichloro-2-pyridinol (TCP), which is water-soluble and toxic. Bacteria can degrade chlorpyrifos and TCP, but the biodegradation mechanism has not been well-characterized. Recently isolated Cupriavidus nantongensis X1T can completely degrade 100 mg/L chlorpyrifos and 20 mg/L TCP with half-lives of 6 and 8 h, respectively. We annotated a complete gene cluster responsible for TCP degradation in recently sequenced strain X1T. Two key genes, tcpA and fre, were cloned from X1T and transferred and expressed in Escherichia coli BL21(DE3). Degradation of TCP by X1T whole cell was compared with that by the enzymes 2,4,6-trichlorophenol monooxygenase and NAD(P)H:flavin reductase expressed and purified from E. coli BL21(DE3). Novel metabolites of TCP were isolated and characterized, indicating stepwise dechlorination of TCP, which was confirmed by TCP disappearance, mass balance, and detection and formation kinetics of chloride ion from TCP.
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Affiliation(s)
- Liancheng Fang
- Key Laboratory for Agri-Food Safety, School of Resource & Environment , Anhui Agricultural University , Hefei , Anhui 230036 , China
| | - Taozhong Shi
- Key Laboratory for Agri-Food Safety, School of Resource & Environment , Anhui Agricultural University , Hefei , Anhui 230036 , China
| | - Yifei Chen
- Key Laboratory for Agri-Food Safety, School of Resource & Environment , Anhui Agricultural University , Hefei , Anhui 230036 , China
| | - Xiangwei Wu
- Key Laboratory for Agri-Food Safety, School of Resource & Environment , Anhui Agricultural University , Hefei , Anhui 230036 , China
| | - Chao Zhang
- Key Laboratory for Agri-Food Safety, School of Resource & Environment , Anhui Agricultural University , Hefei , Anhui 230036 , China
| | - Xinyun Tang
- School of Life Science , Anhui Agricultural University , Hefei Anhui 230036 , China
| | - Qing X Li
- Key Laboratory for Agri-Food Safety, School of Resource & Environment , Anhui Agricultural University , Hefei , Anhui 230036 , China
- Department of Molecular Biosciences and Bioengineering , University of Hawaii at Manoa , 1955 East-West Road , Honolulu , Hawaii 96822 , United States
| | - Rimao Hua
- Key Laboratory for Agri-Food Safety, School of Resource & Environment , Anhui Agricultural University , Hefei , Anhui 230036 , China
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Tavares GC, Carvalho AF, Pereira FL, Rezende CP, Azevedo VAC, Leal CAG, Figueiredo HCP. Transcriptome and Proteome of Fish-Pathogenic Streptococcus agalactiae Are Modulated by Temperature. Front Microbiol 2018; 9:2639. [PMID: 30450092 PMCID: PMC6224512 DOI: 10.3389/fmicb.2018.02639] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 10/16/2018] [Indexed: 12/23/2022] Open
Abstract
Streptococcus agalactiae is one of the most important pathogens associated with streptococcosis outbreaks in Nile tilapia farms worldwide. High water temperature (above 27°C) has been described as a predisposing factor for the disease in fish. At low temperatures (below 25°C), fish mortalities are not usually observed in farms. Temperature variation can modulate the expression of genes and proteins involved in metabolism, adaptation, and bacterial pathogenicity, thus increasing or decreasing the ability to infect the host. This study aimed to evaluate the transcriptome and proteome of a fish-pathogenic S. agalactiae strain SA53 subjected to in vitro growth at different temperatures using a microarray and label-free shotgun LC-HDMSE approach. Biological triplicates of isolates were cultured in BHIT broth at 22 or 32°C for RNA and protein isolation and submitted for transcriptomic and proteomic analyses. In total, 1,730 transcripts were identified in SA53, with 107 genes being differentially expressed between the temperatures evaluated. A higher number of genes related to metabolism, mainly from the phosphotransferase system (PTS) and ATP-binding cassette (ABC) transport system, were upregulated at 32°C. In the proteome analysis, 1,046 proteins were identified in SA53, of which 81 were differentially regulated between 22 and 32°C. Proteins involved in defense mechanisms, lipid transport and metabolism, and nucleotide transport and metabolism were upregulated at 32°C. A higher number of interactions were observed in proteins involved in nucleotide transport and metabolism. We observed a low correlation between the transcriptome and proteome datasets. Our study indicates that the transcriptome and proteome of a fish-adapted S. agalactiae strain are modulated by temperature, particularly showing differential expression of genes/proteins involved in metabolism, virulence factors, and adaptation.
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Affiliation(s)
- Guilherme C Tavares
- AQUACEN-National Reference Laboratory of Aquatic Animal Diseases, Ministry of Agriculture, Livestock and Food Supply, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Alex F Carvalho
- AQUACEN-National Reference Laboratory of Aquatic Animal Diseases, Ministry of Agriculture, Livestock and Food Supply, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Felipe L Pereira
- AQUACEN-National Reference Laboratory of Aquatic Animal Diseases, Ministry of Agriculture, Livestock and Food Supply, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Cristiana P Rezende
- AQUACEN-National Reference Laboratory of Aquatic Animal Diseases, Ministry of Agriculture, Livestock and Food Supply, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Vasco A C Azevedo
- LGCM-Laboratory of Cellular and Molecular Genetics, Biological Science Institute, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Carlos A G Leal
- AQUACEN-National Reference Laboratory of Aquatic Animal Diseases, Ministry of Agriculture, Livestock and Food Supply, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Henrique C P Figueiredo
- AQUACEN-National Reference Laboratory of Aquatic Animal Diseases, Ministry of Agriculture, Livestock and Food Supply, Veterinary School, Federal University of Minas Gerais, Belo Horizonte, Brazil
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Flores-Herrera P, Arredondo-Zelada O, Marshall SH, Gómez FA. Selection and validation of reliable housekeeping genes to evaluate Piscirickettsia salmonis gene expression. INFECTION GENETICS AND EVOLUTION 2018; 63:151-157. [PMID: 29860100 DOI: 10.1016/j.meegid.2018.05.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Revised: 05/15/2018] [Accepted: 05/30/2018] [Indexed: 12/30/2022]
Abstract
Piscirickettsia salmonis is a highly aggressive facultative intracellular bacterium that challenges the sustainability of Chilean salmon production. Due to the limited knowledge of its biology, there is a need to identify key molecular markers that could help define the pathogenic potential of this bacterium. We think a model system should be implemented that efficiently evaluates the expression of putative bacterial markers by using validated, stable, and highly specific housekeeping genes to properly select target genes, which could lead to identifying those responsible for infection and disease induction in naturally infected fish. Here, we selected a set of validated reference or housekeeping genes for RT-qPCR expression analyses of P. salmonis under different growth and stress conditions, including an in vitro infection kinetic. After a thorough screening, we selected sdhA as the most reliable housekeeping gene able to represent stable and highly specific host reference genes for RT-qPCR-driven P. salmonis analysis.
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Affiliation(s)
- Patricio Flores-Herrera
- Laboratorio de Genética e Inmunología Molecular, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Av. Universidad 330 Curauma, Valparaíso, Chile.
| | - Oscar Arredondo-Zelada
- Laboratorio de Genética e Inmunología Molecular, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Av. Universidad 330 Curauma, Valparaíso, Chile
| | - Sergio H Marshall
- Laboratorio de Genética e Inmunología Molecular, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Av. Universidad 330 Curauma, Valparaíso, Chile.
| | - Fernando A Gómez
- Laboratorio de Genética e Inmunología Molecular, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Av. Universidad 330 Curauma, Valparaíso, Chile.
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30
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Yang L, Chen J, Liu Y, Zhang S, Li S, Ding W. Validation of reference genes for quantitative gene expression analysis in Ralstonia pseudosolanacearum CQPS-1 under environment stress. J Microbiol Methods 2018; 148:104-109. [PMID: 29653150 DOI: 10.1016/j.mimet.2018.04.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 03/31/2018] [Accepted: 04/08/2018] [Indexed: 11/19/2022]
Abstract
Quantitative real-time reverse transcriptase PCR (qRT-PCR) has become the method choice for quantification of gene expression changes, however, the accuracy of the method depends on the stability of reference genes. Ralstonia pseudosolanacearum (R. pseudosolanacearum) is an important plant pathogen, infecting >450 plant species and causing bacterial wilt. In order to identify stable reference genes in R. pseudosolanacearum CQPS-1 under different environment stresses. We used five tools (△Ct method, GeNorm, NormFinder, BestKeeper, and RefFinder) to evaluate the stability of seven candidate reference genes including phosphoglycerate kinase (PGK), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), 16S ribosomal RNA (16S), cell division protein ftsZ (ftsZ), DNA gyrase subunit A (gyrA), Ribosomal protein L13 (rplM), and phosphoserine aminotransferase (serC) under biotic (growth phases) and abiotic stress (temperature, hydroxycoumarins, nutrition). Overall, gyrA and serC were the most stable genes under different growth phases, while serC, gyrA and ftsZ during temperature stress, gyrA, ftsZ and 16S under hydroxycoumarins stress, and serC and 16S under nutrition stress conditions. This study provides useful resources for normalizing expression changes of target genes in R. pseudosolanacearum subjected to environment stress.
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Affiliation(s)
- Liang Yang
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Juanni Chen
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Ying Liu
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Shuting Zhang
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Shili Li
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Wei Ding
- Laboratory of Natural Products Pesticides, College of Plant Protection, Southwest University, Chongqing 400715, China.
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Polese V, de Paula Soares C, da Silva PRA, Simões-Araújo JL, Baldani JI, Vidal MS. Selection and validation of reference genes for RT-qPCR indicates that juice of sugarcane varieties modulate the expression of C metabolism genes in the endophytic diazotrophic Herbaspirillum rubrisubalbicans strain HCC103. Antonie Van Leeuwenhoek 2017; 110:1555-1568. [DOI: 10.1007/s10482-017-0906-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Accepted: 06/28/2017] [Indexed: 12/24/2022]
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Kim H, Park D, Yoon S. pH Control Enables Simultaneous Enhancement of Nitrogen Retention and N 2O Reduction in Shewanella loihica Strain PV-4. Front Microbiol 2017; 8:1820. [PMID: 28979255 PMCID: PMC5611402 DOI: 10.3389/fmicb.2017.01820] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 09/06/2017] [Indexed: 11/13/2022] Open
Abstract
pH has been recognized as one of the key environmental parameters with significant impacts on the nitrogen cycle in the environment. In this study, the effects of pH on NO3-/NO2- fate and N2O emission were examined with Shewanella loihica strain PV-4, an organism with complete denitrification and respiratory ammonification pathways. Strain PV-4 was incubated at varying pH with lactate as the electron donor and NO3-/NO2- and N2O as the electron acceptors. When incubated with NO3- and N2O at pH 6.0, transient accumulation of N2O was observed and no significant NH4+ production was observed. At pH 7.0 and 8.0, strain PV-4 served as a N2O sink, as N2O concentration decreased consistently without accumulation. Respiratory ammonification was upregulated in the experiments performed at these higher pH values. When NO2- was used in place of NO3-, neither growth nor NO2- reduction was observed at pH 6.0. NH4+ was the exclusive product from NO2- reduction at both pH 7.0 and 8.0 and neither production nor consumption of N2O was observed, suggesting that NO2- regulation superseded pH effects on the nitrogen-oxide dissimilation reactions. When NO3- was the electron acceptor, nirK transcription was significantly upregulated upon cultivation at pH 6.0, while nrfA transcription was significantly upregulated at pH 8.0. The highest level of nosZ transcription was observed at pH 6.0 and the lowest at pH 8.0. With NO2- as the electron acceptor, transcription profiles of nirK, nrfA, and nosZ were statistically indistinguishable between pH 7.0 and 8.0. The transcriptions of nirK and nosZ were severely downregulated regardless of pH. These observations suggested that the kinetic imbalance between N2O production and consumption, but neither decrease in expression nor activity of NosZ, was the major cause of N2O accumulation at pH 6.0. The findings also suggest that simultaneous enhancement of nitrogen retention and N2O emission reduction may be feasible through pH modulation, but only in environments where C:N or NO2-:NO3- ratio does not exhibit overarching control over the NO3-/NO2- reduction pathways.
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Affiliation(s)
- Hayeon Kim
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and TechnologyDaejeon, South Korea
| | - Doyoung Park
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and TechnologyDaejeon, South Korea
| | - Sukhwan Yoon
- Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and TechnologyDaejeon, South Korea
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Validation of reference genes for the normalization of the RT-qPCR gene expression of virulence genes of Erwinia amylovora in apple shoots. Sci Rep 2017; 7:2034. [PMID: 28515453 PMCID: PMC5435713 DOI: 10.1038/s41598-017-02078-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 04/05/2017] [Indexed: 01/11/2023] Open
Abstract
To study the expression of pathogenicity-related genes in Erwinia amylovora, seven candidate reference genes (ffh, glyA, gyrA, proC, pykA, recA, rpoB) were selected and validated with the following five different mathematic algorithms: geNorm, NormFinder, BestKeeper, the delta CT method and the RefFinder web-based tool. An overall comprehensive ranking output from each of the selected software programs revealed that proC and recA, followed by ffh and pykA, were the most stably expressed genes and can be recommended for the normalization of RT-qPCR data. A combination of the three reference genes, proC, recA and ffh, allowed for the accurate expression analysis of amsB and hrpN genes and the calculation of their fold change in E. amylovora after its infection of susceptible and resistant apple cultivars. To the best of our knowledge, this is the first study presenting a list of the most suitable reference genes for use in the relative quantification of target gene expression in E. amylovora in planta, selected on the basis of a multi-algorithm analysis.
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Anabestani A, Izadpanah K, Abbà S, Galetto L, Ghorbani A, Palmano S, Siampour M, Veratti F, Marzachì C. Identification of putative effector genes and their transcripts in three strains related to 'Candidatus Phytoplasma aurantifolia'. Microbiol Res 2017; 199:57-66. [PMID: 28454710 DOI: 10.1016/j.micres.2017.03.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 02/22/2017] [Accepted: 03/04/2017] [Indexed: 11/25/2022]
Abstract
Molecular mechanisms underlying phytoplasma interactions with host plants are largely unknown. In this study attempts were made to identify effectors of three phytoplasma strains related to 'Ca. P. aurantifolia', crotalaria phyllody (CrP), faba bean phyllody (FBP), and witches' broom disease of lime (WBDL), using information from draft genome of peanut witches' broom phytoplasma. Seven putative effectors were identified in WBDL genome (SAP11, SAP21, Eff64, Eff115, Eff197, Eff211 and EffSAP67), five (SAP11, SAP21, Eff64, Eff99 and Eff197) in CrP and two (SAP11, Eff64) in FBP. No homologs to Eff64, Eff197 and Eff211 in phytoplasmas of other phylogenetic groups were found. SAP11 and Eff64 homologs of 'Ca. P. aurantifolia' strains shared at least 95.9% identity and were detected in the three phytoplasmas, supporting their role within the group. Five of the putative effectors (SAP11, SAP21, Eff64, Eff115, and Eff99) were transcribed from total RNA extracts of periwinkle plants infected with these phytoplasmas. Transcription profiles of selected putative effectors of CrP, FBP and WBDL indicated that SAP11 transcripts were the most abundant in the three phytoplasmas. SAP21 transcript levels were comparable to those of SAP11 for CrP and not measurable for the other phytoplasmas. Eff64 had the lowest transcription level irrespective of sampling date and phytoplasma isolate. Eff115 transcript levels were the highest in WBDL infected plants. This work reports the first sequence information for 14 putative effectors in three strains related to 'Ca. P. aurantifolia', and offers novel insight into the transcription profile of five of them during infection of periwinkle.
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Affiliation(s)
- Ameneh Anabestani
- Istituto per la Protezione Sostenibile delle Piante, CNR, Strada delle Cacce 73, I-10135, Torino, Italy; Plant Virology Research Center, College of Agriculture, Shiraz University, Shiraz, Iran
| | - Keramat Izadpanah
- Plant Virology Research Center, College of Agriculture, Shiraz University, Shiraz, Iran
| | - Simona Abbà
- Istituto per la Protezione Sostenibile delle Piante, CNR, Strada delle Cacce 73, I-10135, Torino, Italy
| | - Luciana Galetto
- Istituto per la Protezione Sostenibile delle Piante, CNR, Strada delle Cacce 73, I-10135, Torino, Italy
| | - Abozar Ghorbani
- Plant Virology Research Center, College of Agriculture, Shiraz University, Shiraz, Iran
| | - Sabrina Palmano
- Istituto per la Protezione Sostenibile delle Piante, CNR, Strada delle Cacce 73, I-10135, Torino, Italy
| | - Majid Siampour
- Department of Plant Protection, Shahrekord University, Shahrekord, Iran
| | - Flavio Veratti
- Istituto per la Protezione Sostenibile delle Piante, CNR, Strada delle Cacce 73, I-10135, Torino, Italy
| | - Cristina Marzachì
- Istituto per la Protezione Sostenibile delle Piante, CNR, Strada delle Cacce 73, I-10135, Torino, Italy.
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Wang J, Feng Y, Wang C, Srinivas S, Chen C, Liao H, He E, Jiang S, Tang J. Pathogenic Streptococcus strains employ novel escape strategy to inhibit bacteriostatic effect mediated by mammalian peptidoglycan recognition protein. Cell Microbiol 2017; 19. [PMID: 28092693 DOI: 10.1111/cmi.12724] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 01/05/2017] [Accepted: 01/09/2017] [Indexed: 01/06/2023]
Abstract
Pathogenic streptococcal species are responsible for some of the most lethal and prevalent animal and human infections. Previous reports have identified a candidate pathogenicity island (PAI) in two highly virulent clinical isolates of Streptococcus suis type 2, a causative agent of high-mortality streptococcal toxic shock syndrome. This PAI contains a type-IVC secretion system C subgroup (type-IVC secretion system) that is involved in the secretion of unknown pathogenic effectors that are responsible for streptococcal toxic shock syndrome caused by highly virulent strains of S. suis. Both virulence protein B4 and virulence protein D4 were demonstrated to be key components of this type-IVC secretion system. In this study, we identify a new PAI family across 3 streptococcal species; Streptococcus genomic island contains type-IV secretion system, which contains a genomic island type-IVC secretion system and a novel PPIase molecule, SP1. SP1 is shown to interact with a component of innate immunity, peptidoglycan recognition protein (PGLYRP-1) and to perturb the PGLYRP-1-mediated bacteriostatic effect by interacting with protein PGLYRP-1. Our study elucidates a novel mechanism by which bacteria escape by components of the innate immune system by secretion of the SP1 protein in pathogenic Streptococci, which then interacts with PGLYRP-1 from the host. Our results provide potential targets for the development of new antimicrobial drugs against bacteria with resistance to innate host immunity.
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Affiliation(s)
- Jing Wang
- Translational Medicine Center, PLA Hospital No.454, Nanjing, China
| | - Youjun Feng
- Department of Medical Microbiology Parasitology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Changjun Wang
- Department of Epidemiology, Medicinal Research Institute, Nanjing Military Command, Nanjing, China
| | - Swaminath Srinivas
- Department of Medical Microbiology Parasitology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Chen Chen
- Chinese Center for Disease Control and Prevention, Beijing, China
| | - Hui Liao
- Translational Medicine Center, PLA Hospital No.454, Nanjing, China
| | - Elaine He
- The Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Shibo Jiang
- Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY, USA
| | - Jiaqi Tang
- PLA Research Institute of Clinical Laboratory Medicine, Nanjing General Hospital, Nanjing Military Command, Nanjing, China
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Pinto M, Antelo M, Ferreira R, Azevedo J, Santo I, Borrego MJ, Gomes JP. A retrospective cross-sectional quantitative molecular approach in biological samples from patients with syphilis. Microb Pathog 2017; 104:296-302. [PMID: 28161356 DOI: 10.1016/j.micpath.2017.01.059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 01/25/2017] [Accepted: 01/31/2017] [Indexed: 10/20/2022]
Abstract
Syphilis is the sexually transmitted disease caused by Treponema pallidum, a pathogen highly adapted to the human host. As a multistage disease, syphilis presents distinct clinical manifestations that pose different implications for diagnosis. Nevertheless, the inherent factors leading to diverse disease progressions are still unknown. We aimed to assess the association between treponemal loads and dissimilar disease outcomes, to better understand syphilis. We retrospectively analyzed 309 DNA samples distinct anatomic sites associated with particular syphilis manifestations. All samples had previously tested positive by a PCR-based diagnostic kit. An absolute quantitative real-time PCR procedure was used to precisely quantify the number of treponemal and human cells to determine T. pallidum loads in each sample. In general, lesion exudates presented the highest T. pallidum loads in contrast with blood-derived samples. Within the latter, a higher dispersion of T. pallidum quantities was observed for secondary syphilis. T. pallidum was detected in substantial amounts in 37 samples of seronegative individuals and in 13 cases considered as syphilis-treated. No association was found between treponemal loads and serological results or HIV status. This study suggests a scenario where syphilis may be characterized by: i) heterogeneous and high treponemal loads in primary syphilis, regardless of the anatomic site, reflecting dissimilar duration of chancres development and resolution; ii) high dispersion of bacterial concentrations in secondary syphilis, potentially suggesting replication capability of T. pallidum while in the bloodstream; and iii) bacterial evasiveness, either to the host immune system or antibiotic treatment, while remaining hidden in privileged niches. This work highlights the importance of using molecular approaches to study uncultivable human pathogens, such as T. pallidum, in the infection process.
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Affiliation(s)
- Miguel Pinto
- Reference Laboratory of Bacterial Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Av. Padre Cruz, 1649-016, Lisbon, Portugal
| | - Minia Antelo
- Reference Laboratory of Bacterial Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Av. Padre Cruz, 1649-016, Lisbon, Portugal
| | - Rita Ferreira
- Reference Laboratory of Bacterial Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Av. Padre Cruz, 1649-016, Lisbon, Portugal
| | - Jacinta Azevedo
- Sexually Transmitted Diseases Clinic, Lapa Health Centre, Rua de S. Ciro, 36, 1200-831, Lisbon, Portugal
| | - Irene Santo
- Sexually Transmitted Diseases Clinic, Lapa Health Centre, Rua de S. Ciro, 36, 1200-831, Lisbon, Portugal
| | - Maria José Borrego
- Reference Laboratory of Bacterial Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Av. Padre Cruz, 1649-016, Lisbon, Portugal
| | - João Paulo Gomes
- Reference Laboratory of Bacterial Sexually Transmitted Infections, Department of Infectious Diseases, National Institute of Health, Av. Padre Cruz, 1649-016, Lisbon, Portugal; Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Av. Padre Cruz, 1649-016, Lisbon, Portugal.
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Kurt-Kızıldoğan A, Abanoz B, Okay S. Global transcriptome analysis of Halolamina sp. to decipher the salt tolerance in extremely halophilic archaea. Gene 2016; 601:56-64. [PMID: 27919704 DOI: 10.1016/j.gene.2016.11.042] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/17/2016] [Accepted: 11/30/2016] [Indexed: 12/21/2022]
Abstract
Extremely halophilic archaea survive in the hypersaline environments such as salt lakes or salt mines. Therefore, these microorganisms are good sources to investigate the molecular mechanisms underlying the tolerance to high salt concentrations. In this study, a global transcriptome analysis was conducted in an extremely halophilic archaeon, Halolamina sp. YKT1, isolated from a salt mine in Turkey. A comparative RNA-seq analysis was performed using YKT1 isolate grown either at 2.7M NaCl or 5.5M NaCl concentrations. A total of 2149 genes were predicted to be up-regulated and 1638 genes were down-regulated in the presence of 5.5M NaCl. The salt tolerance of Halolamina sp. YKT1 involves the up-regulation of genes related with membrane transporters, CRISPR-Cas systems, osmoprotectant solutes, oxidative stress proteins, and iron metabolism. On the other hand, the genes encoding the proteins involved in DNA replication, transcription, translation, mismatch and nucleotide excision repair were down-regulated. The RNA-seq data were verified for seven up-regulated genes as well as six down-regulated genes via qRT-PCR analysis. This comprehensive transcriptome analysis showed that the halophilic archaeon canalizes its energy towards keeping the intracellular osmotic balance minimizing the production of nucleic acids and peptides.
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Affiliation(s)
- Aslıhan Kurt-Kızıldoğan
- Department of Agricultural Biotechnology, Faculty of Agriculture, Ondokuz Mayıs University, 55139 Samsun, Turkey
| | - Büşra Abanoz
- Department of Agricultural Biotechnology, Faculty of Agriculture, Ondokuz Mayıs University, 55139 Samsun, Turkey
| | - Sezer Okay
- Department of Biology, Faculty of Science, Çankırı Karatekin University, 18100 Çankırı, Turkey.
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Wu BY, Ye JR, Huang L, He LM, Li DW. Validation of reference genes for RT-qPCR analysis in Burkholderia pyrrocinia JK-SH007. J Microbiol Methods 2016; 132:95-98. [PMID: 27725176 DOI: 10.1016/j.mimet.2016.10.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 10/06/2016] [Accepted: 10/06/2016] [Indexed: 11/18/2022]
Abstract
Burkholderia pyrrocinia strain JK-SH007 isolated from poplar stems plays a highly significant role in the growth promotion and the biocontrol of poplar canker during colonization in poplar. In this research, the ideal reference gene was filtered and determined for the transcript normalization. Additionally, the expression of pyrG under all four conditions was relatively stable in B. pyrrocinia JK-SH007.
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Affiliation(s)
- Bin-Yan Wu
- College of Forestry and Co-Innovation Center for Sustainable Forestry in Southern China, Jiangsu Key Laboratory for Prevention and Management of Invasive Species, Nanjing Forestry University, Nanjing, Jiangsu, China
| | - Jian-Ren Ye
- College of Forestry and Co-Innovation Center for Sustainable Forestry in Southern China, Jiangsu Key Laboratory for Prevention and Management of Invasive Species, Nanjing Forestry University, Nanjing, Jiangsu, China.
| | - Lin Huang
- College of Forestry and Co-Innovation Center for Sustainable Forestry in Southern China, Jiangsu Key Laboratory for Prevention and Management of Invasive Species, Nanjing Forestry University, Nanjing, Jiangsu, China
| | - Ling-Min He
- College of Forestry and Co-Innovation Center for Sustainable Forestry in Southern China, Jiangsu Key Laboratory for Prevention and Management of Invasive Species, Nanjing Forestry University, Nanjing, Jiangsu, China
| | - De-Wei Li
- College of Forestry and Co-Innovation Center for Sustainable Forestry in Southern China, Jiangsu Key Laboratory for Prevention and Management of Invasive Species, Nanjing Forestry University, Nanjing, Jiangsu, China; The Connecticut Agricultural Experiment Station, Valley Laboratory, 153 Cook Hill Road, Windsor, CT, United States
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Tomada S, Puopolo G, Perazzolli M, Musetti R, Loi N, Pertot I. Pea Broth Enhances the Biocontrol Efficacy of Lysobacter capsici AZ78 by Triggering Cell Motility Associated with Biogenesis of Type IV Pilus. Front Microbiol 2016; 7:1136. [PMID: 27507963 PMCID: PMC4960238 DOI: 10.3389/fmicb.2016.01136] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 07/07/2016] [Indexed: 12/18/2022] Open
Abstract
Bacterial cells can display different types of motility, due to the presence of external appendages such as flagella and type IV pili. To date, little information on the mechanisms involved in the motility of the Lysobacter species has been available. Recently, L. capsici AZ78, a biocontrol agent of phytopathogenic oomycetes, showed the ability to move on jellified pea broth. Pea broth medium improved also the biocontrol activity of L. capsici AZ78 against Plasmopara viticola under greenhouse conditions. Noteworthy, the quantity of pea residues remaining on grapevine leaves fostered cell motility in L. capsici AZ78. Based on these results, this unusual motility related to the composition of the growth medium was investigated in bacterial strains belonging to several Lysobacter species. The six L. capsici strains tested developed dendrite-like colonies when grown on jellified pea broth, while the development of dendrite-like colonies was not recorded in the media commonly used in motility assays. To determine the presence of genes responsible for biogenesis of the flagellum and type IV pili, the genome of L. capsici AZ78 was mined. Genes encoding structural components and regulatory factors of type IV pili were upregulated in L. capsici AZ78 cells grown on the above-mentioned medium, as compared with the other tested media. These results provide new insight into the motility mechanism of L. capsici members and the role of type IV pili and pea compounds on the epiphytic fitness and biocontrol features of L. capsici AZ78.
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Affiliation(s)
- Selena Tomada
- Department of Sustainable Agro-Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund MachSan Michele all'Adige, Italy; Agricultural Science and Biotechnology Program, Department of Agricultural, Food, Environmental, and Animal Sciences, University of UdineUdine, Italy
| | - Gerardo Puopolo
- Department of Sustainable Agro-Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach San Michele all'Adige, Italy
| | - Michele Perazzolli
- Department of Sustainable Agro-Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach San Michele all'Adige, Italy
| | - Rita Musetti
- Department of Agricultural, Food, Environmental, and Animal Sciences, University of Udine Udine, Italy
| | - Nazia Loi
- Department of Agricultural, Food, Environmental, and Animal Sciences, University of Udine Udine, Italy
| | - Ilaria Pertot
- Department of Sustainable Agro-Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach San Michele all'Adige, Italy
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40
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Prickett MH, Hauser AR, McColley SA, Cullina J, Potter E, Powers C, Jain M. Aminoglycoside resistance of Pseudomonas aeruginosa in cystic fibrosis results from convergent evolution in the mexZ gene. Thorax 2016; 72:40-47. [PMID: 27325751 DOI: 10.1136/thoraxjnl-2015-208027] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 05/10/2016] [Accepted: 05/24/2016] [Indexed: 01/17/2023]
Abstract
RATIONALE Aminoglycoside (AG) resistance of Pseudomonas aeruginosa in cystic fibrosis (CF) is associated with poorer clinical outcomes and is usually due to overexpression of the efflux pump MexXY. MexXY is regulated by mexZ, one of the most commonly mutated genes in CF P. aeruginosa isolates. Little is known about the evolutionary relationship between AG resistance, MexXY expression and mexZ mutations. OBJECTIVES To test the hypothesis that AG resistance in P. aeruginosa develops in parallel with higher MexXY expression and mexZ mutations. METHODS CF P. aeruginosa isolates were compared for chronically infected (CI) adults, CI children and children with new infection. MEASUREMENTS One P. aeruginosa isolate from each patient was analysed for mexZ mutations, mexY mRNA expression and amikacin resistance. MAIN RESULTS 56 patients with CF were enrolled: 21 children with new P. aeruginosa infection, 18 CI children and 17 CI adults. Amikacin resistance and mexY mRNA expression were higher in cohorts with longer P. aeruginosa infection. The prevalence of non-conservative mexZ mutations was 0%, 33% and 65% in children with new infection, CI children and CI adults, respectively. The same trend was seen in the ratio of non-conservative to non-synonymous mexZ mutations. Of isolates with non-conservative mexZ mutations, 59% were amikacin-resistant compared with 18% of isolates with non-synonymous mutations. The doubling rate of amikacin resistance and non-conservative mexZ mutations was approximately 5 years. CONCLUSIONS P. aeruginosa mexZ mutations undergo positive selection resulting in increased mexY mRNA expression and amikacin resistance and likely play a role in bacterial adaption in the CF lung.
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Affiliation(s)
- Michelle H Prickett
- Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Alan R Hauser
- Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Susanna A McColley
- Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.,Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA
| | - Joanne Cullina
- Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA
| | - Eileen Potter
- Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA
| | - Cathy Powers
- Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA
| | - Manu Jain
- Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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41
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Pessoa DDV, Vidal MS, Baldani JI, Simoes-Araujo JL. Validation of reference genes for RT-qPCR analysis in Herbaspirillum seropedicae. J Microbiol Methods 2016; 127:193-196. [PMID: 27302038 DOI: 10.1016/j.mimet.2016.06.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 06/09/2016] [Accepted: 06/10/2016] [Indexed: 11/17/2022]
Abstract
The RT-qPCR technique needs a validated set of reference genes for ensuring the consistency of the results from the gene expression. Expression stabilities for 9 genes from Herbaspirillum seropedicae, strain HRC54, grown with different carbon sources were calculated using geNorm and NormFinder, and the gene rpoA showed the best stability values.
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Affiliation(s)
- Daniella Duarte Villarinho Pessoa
- Universidade Federal do Rio de Janeiro - UFRJ, Programa de Pós-Graduação em Biotecnologia Vegetal, Centro de Ciências da Saúde - CCS, Campus Ilha do Fundão, Av. Carlos Chagas Filho, 373 - Cidade Universitária, CEP: 21941-590 Rio de Janeiro, RJ, Brazil; Centro Nacional de Pesquisa de Agrobiologia, CNPAB, Embrapa, Laboratório de Genética e Bioquímica, Embrapa Agrobiologia, BR 465, Km 7, s/n, Pavilhão Johanna Döbereiner, Bairro Ecologia, CEP: 23890-000 Seropédica, RJ, Brazil.
| | - Marcia Soares Vidal
- Centro Nacional de Pesquisa de Agrobiologia, CNPAB, Embrapa, Laboratório de Genética e Bioquímica, Embrapa Agrobiologia, BR 465, Km 7, s/n, Pavilhão Johanna Döbereiner, Bairro Ecologia, CEP: 23890-000 Seropédica, RJ, Brazil
| | - José Ivo Baldani
- Centro Nacional de Pesquisa de Agrobiologia, CNPAB, Embrapa, Laboratório de Genética e Bioquímica, Embrapa Agrobiologia, BR 465, Km 7, s/n, Pavilhão Johanna Döbereiner, Bairro Ecologia, CEP: 23890-000 Seropédica, RJ, Brazil
| | - Jean Luiz Simoes-Araujo
- Centro Nacional de Pesquisa de Agrobiologia, CNPAB, Embrapa, Laboratório de Genética e Bioquímica, Embrapa Agrobiologia, BR 465, Km 7, s/n, Pavilhão Johanna Döbereiner, Bairro Ecologia, CEP: 23890-000 Seropédica, RJ, Brazil.
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Petrova O, Gorshkov V, Sergeeva I, Daminova A, Ageeva M, Gogolev Y. Alternative scenarios of starvation-induced adaptation in Pectobacterium atrosepticum. Res Microbiol 2016; 167:254-261. [DOI: 10.1016/j.resmic.2016.01.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 01/29/2016] [Accepted: 01/29/2016] [Indexed: 12/01/2022]
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Shabayek S, Bauer R, Mauerer S, Mizaikoff B, Spellerberg B. A streptococcal NRAMP homologue is crucial for the survival of Streptococcus agalactiae under low pH conditions. Mol Microbiol 2016; 100:589-606. [PMID: 27150893 DOI: 10.1111/mmi.13335] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/24/2016] [Indexed: 12/25/2022]
Abstract
Streptococcus agalactiae or Group B Streptococcus (GBS) is a commensal bacterium of the human gastrointestinal and urogenital tracts as well as a leading cause of neonatal sepsis, pneumonia and meningitis. Maternal vaginal carriage is the main source for GBS transmission and thus the most important risk factor for neonatal disease. Several studies in eukaryotes identified a group of proteins natural resistance-associated macrophage protein (NRAMP) that function as divalent cation transporters for Fe(2+) and Mn(2+) and confer on macrophages the ability to control replication of bacterial pathogens. Genome sequencing predicted potential NRAMP homologues in several prokaryotes. Here we describe for the first time, a pH-regulated NRAMP Mn(2+) /Fe(2+) transporter in GBS, designated MntH, which confers resistance to reactive oxygen species (ROS) and is crucial for bacterial growth and survival under low pH conditions. Our investigation implicates MntH as an important colonization determinant for GBS in the maternal vagina as it helps bacteria to adapt to the harsh acidic environment, facilitates bacterial adherence, contributes to the coexistence with the vaginal microbiota and plays a role in GBS intracellular survival inside macrophages.
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Affiliation(s)
- Sarah Shabayek
- Institute of Medical Microbiology and Hygiene, University of Ulm, Ulm, Germany.,Microbiology and Immunology Department, Faculty of Pharmacy, Suez Canal University, Ismailia, Egypt
| | - Richard Bauer
- Institute of Medical Microbiology and Hygiene, University of Ulm, Ulm, Germany
| | - Stefanie Mauerer
- Institute of Medical Microbiology and Hygiene, University of Ulm, Ulm, Germany
| | - Boris Mizaikoff
- Institute of Analytical and Bioanalytical Chemistry, University of Ulm, Ulm, Germany
| | - Barbara Spellerberg
- Institute of Medical Microbiology and Hygiene, University of Ulm, Ulm, Germany
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Ma YJ, Sun XH, Xu XY, Zhao Y, Pan YJ, Hwang CA, Wu VCH. Investigation of Reference Genes in Vibrio parahaemolyticus for Gene Expression Analysis Using Quantitative RT-PCR. PLoS One 2015; 10:e0144362. [PMID: 26659406 PMCID: PMC4676679 DOI: 10.1371/journal.pone.0144362] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Accepted: 11/17/2015] [Indexed: 01/14/2023] Open
Abstract
Vibrio parahaemolyticus is a significant human pathogen capable of causing foodborne gastroenteritis associated with the consumption of contaminated raw or undercooked seafood. Quantitative RT-PCR (qRT-PCR) is a useful tool for studying gene expression in V. parahaemolyticus to characterize its virulence factors and understand the effect of environmental conditions on its pathogenicity. However, there is not a stable gene in V. parahaemolyticus that has been identified for use as a reference gene for qRT-PCR. This study evaluated the stability of 6 reference genes (16S rRNA, recA, rpoS, pvsA, pvuA, and gapdh) in 5 V. parahaemolyticus strains (O3:K6-clinical strain-tdh+, ATCC33846-tdh+, ATCC33847-tdh+, ATCC17802-trh+, and F13-environmental strain-tdh+) cultured at 4 different temperatures (15, 25, 37 and 42°C). Stability values were calculated using GeNorm, NormFinder, BestKeeper, and Delta CT algorithms. The results indicated that recA was the most stably expressed gene in the V. parahaemolyticus strains cultured at different temperatures. This study examined multiple V. parahaemolyticus strains and growth temperatures, hence the finding provided stronger evidence that recA can be used as a reference gene for gene expression studies in V. parahaemolyticus.
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Affiliation(s)
- Yue-jiao Ma
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, People's Republic of China
- Shanghai Engineering Research Center of Aquatic Product Processing & Preservation, Shanghai 201306, China
| | - Xiao-hong Sun
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, People's Republic of China
- Shanghai Engineering Research Center of Aquatic Product Processing & Preservation, Shanghai 201306, China
- * E-mail: (VCHW); (XS)
| | - Xiao-yan Xu
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education, Shanghai, People's Republic of China
| | - Yong Zhao
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, People's Republic of China
- Shanghai Engineering Research Center of Aquatic Product Processing & Preservation, Shanghai 201306, China
| | - Ying-jie Pan
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, People's Republic of China
- Shanghai Engineering Research Center of Aquatic Product Processing & Preservation, Shanghai 201306, China
| | - Cheng-An Hwang
- Residue Chemistry and Predictive Microbiology Research Unit, Eastern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, Wyndmoor, PA, 19038, United States of America
| | - Vivian C. H. Wu
- The Pathogenic Microbiology Laboratory, School of Food and Agriculture, University of Maine, Orono, ME, 04469–5735, United States of America
- Produce Safety and Microbiology Research Unit, Western Regional Research Center, Agricultural Research Service, United States Department of Agriculture, Albany, CA, 94710, United States of America
- * E-mail: (VCHW); (XS)
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Zhang C, Xue C, Shen Y, Lu W. Selection of reference genes in Saccharopolyspora spinosa for real-time PCR. ACTA ACUST UNITED AC 2015. [DOI: 10.1007/s12209-015-2637-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Bacterial reference genes for gene expression studies by RT-qPCR: survey and analysis. Antonie van Leeuwenhoek 2015; 108:685-93. [PMID: 26149127 DOI: 10.1007/s10482-015-0524-1] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Accepted: 06/29/2015] [Indexed: 10/23/2022]
Abstract
The appropriate choice of reference genes is essential for accurate normalization of gene expression data obtained by the method of reverse transcription quantitative real-time PCR (RT-qPCR). In 2009, a guideline called the Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) highlighted the importance of the selection and validation of more than one suitable reference gene for obtaining reliable RT-qPCR results. Herein, we searched the recent literature in order to identify the bacterial reference genes that have been most commonly validated in gene expression studies by RT-qPCR (in the first 5 years following publication of the MIQE guidelines). Through a combination of different search parameters with the text mining tool MedlineRanker, we identified 145 unique bacterial genes that were recently tested as candidate reference genes. Of these, 45 genes were experimentally validated and, in most of the cases, their expression stabilities were verified using the software tools geNorm and NormFinder. It is noteworthy that only 10 of these reference genes had been validated in two or more of the studies evaluated. An enrichment analysis using Gene Ontology classifications demonstrated that genes belonging to the functional categories of DNA Replication (GO: 0006260) and Transcription (GO: 0006351) rendered a proportionally higher number of validated reference genes. Three genes in the former functional class were also among the top five most stable genes identified through an analysis of gene expression data obtained from the Pathosystems Resource Integration Center. These results may provide a guideline for the initial selection of candidate reference genes for RT-qPCR studies in several different bacterial species.
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Cusick KD, Fitzgerald LA, Cockrell AL, Biffinger JC. Selection and Evaluation of Reference Genes for Reverse Transcription-Quantitative PCR Expression Studies in a Thermophilic Bacterium Grown under Different Culture Conditions. PLoS One 2015; 10:e0131015. [PMID: 26115538 PMCID: PMC4482720 DOI: 10.1371/journal.pone.0131015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 05/26/2015] [Indexed: 11/18/2022] Open
Abstract
The phylum Deinococcus-Thermus is a deeply-branching lineage of bacteria widely recognized as one of the most extremophilic. Members of the Thermus genus are of major interest due to both their bioremediation and biotechnology potentials. However, the molecular mechanisms associated with these key metabolic pathways remain unknown. Reverse-transcription quantitative PCR (RT-qPCR) is a high-throughput means of studying the expression of a large suite of genes over time and under different conditions. The selection of a stably-expressed reference gene is critical when using relative quantification methods, as target gene expression is normalized to expression of the reference gene. However, little information exists as to reference gene selection in extremophiles. This study evaluated 11 candidate reference genes for use with the thermophile Thermus scotoductus when grown under different culture conditions. Based on the combined stability values from BestKeeper and NormFinder software packages, the following are the most appropriate reference genes when comparing: (1) aerobic and anaerobic growth: TSC_c19900, polA2, gyrA, gyrB; (2) anaerobic growth with varied electron acceptors: TSC_c19900, infA, pfk, gyrA, gyrB; (3) aerobic growth with different heating methods: gyrA, gap, gyrB; (4) all conditions mentioned above: gap, gyrA, gyrB. The commonly-employed rpoC does not serve as a reliable reference gene in thermophiles, due to its expression instability across all culture conditions tested here. As extremophiles exhibit a tendency for polyploidy, absolute quantification was employed to determine the ratio of transcript to gene copy number in a subset of the genes. A strong negative correlation was found to exist between ratio and threshold cycle (CT) values, demonstrating that CT changes reflect transcript copy number, and not gene copy number, fluctuations. Even with the potential for polyploidy in extremophiles, the results obtained via absolute quantification indicate that relative quantification is appropriate for RT-qPCR studies with this thermophile.
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Affiliation(s)
- Kathleen D Cusick
- National Research Council Associateship, US Naval Research Laboratory, 4555 Overlook Ave., SW, Washington DC, 20375, United States of America
| | - Lisa A Fitzgerald
- Chemistry Division, US Naval Research Laboratory, 4555 Overlook Ave., SW, Washington DC, 20375, United States of America
| | - Allison L Cockrell
- National Research Council Associateship, US Naval Research Laboratory, 4555 Overlook Ave., SW, Washington DC, 20375, United States of America
| | - Justin C Biffinger
- Chemistry Division, US Naval Research Laboratory, 4555 Overlook Ave., SW, Washington DC, 20375, United States of America
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Wang X, Ma X, Huang L, Zhang X. Identification of the valid reference genes for quantitative RT-PCR in annual ryegrass (Lolium multiflorum) under salt stress. Molecules 2015; 20:4833-47. [PMID: 25786166 PMCID: PMC6272566 DOI: 10.3390/molecules20034833] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 03/06/2015] [Accepted: 03/10/2015] [Indexed: 01/13/2023] Open
Abstract
Annual ryegrass (Lolium multiflorum) is a cool-season annual grass cultivated worldwide for its high yield and quality. With the areas of saline soil increasing, investigation of the molecular mechanisms of annual ryegrass tolerance under salt stress has become a significant topic. qRT-PCR has been a predominant assay for determination of the gene expression, in which selecting a valid internal reference gene is a crucial step. The objective of present study was to evaluate and identify suitable reference genes for qRT-PCR in annual ryegrass under salt stress. The results calculated by RefFinder indicated that eEF1A(s) was the most stable reference gene in leaves, whereas EF1-a was the least stable; meanwhile, TBP-1 was the most optimal in roots and in all samples, and the eIF-5A shouldn’t be utilized for normalization of the gene expression. eEF1A(s) is more suitable than TBP-1 as reference gene in leaves when verified with P5CS1 and Cyt-Cu/Zn SOD genes. We should choose optimal reference genes in specific tissues instead of the most stable one selected from different conditions and tissues.
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Affiliation(s)
- Xia Wang
- Grassland Science Department, Sichuan Agriculture University, Chengdu 611130, China.
| | - Xiao Ma
- Grassland Science Department, Sichuan Agriculture University, Chengdu 611130, China.
| | - Linkai Huang
- Grassland Science Department, Sichuan Agriculture University, Chengdu 611130, China.
| | - Xinquan Zhang
- Grassland Science Department, Sichuan Agriculture University, Chengdu 611130, China.
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Decreasing global transcript levels over time suggest that phytoplasma cells enter stationary phase during plant and insect colonization. Appl Environ Microbiol 2015; 81:2591-602. [PMID: 25636844 DOI: 10.1128/aem.03096-14] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To highlight different transcriptional behaviors of the phytoplasma in the plant and animal host, expression of 14 genes of "Candidatus Phytoplasma asteris," chrysanthemum yellows strain, was investigated at different times following the infection of a plant host (Arabidopsis thaliana) and two insect vector species (Macrosteles quadripunctulatus and Euscelidius variegatus). Target genes were selected among those encoding antigenic membrane proteins, membrane transporters, secreted proteins, and general enzymes. Transcripts were detected for all analyzed genes in the three hosts; in particular, those encoding the antigenic membrane protein Amp, elements of the mechanosensitive channel, and two of the four secreted proteins (SAP54 and TENGU) were highly accumulated, suggesting that they play important roles in phytoplasma physiology during the infection cycle. Most transcripts were present at higher abundance in the plant host than in the insect hosts. Generally, transcript levels of the selected genes decreased significantly during infection of A. thaliana and M. quadripunctulatus but were more constant in E. variegatus. Such decreases may be explained by the fact that only a fraction of the phytoplasma population was transcribing, while the remaining part was aging to a stationary phase. This strategy might improve long-term survival, thereby increasing the likelihood that the pathogen may be acquired by a vector and/or inoculated to a healthy plant.
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Stenico V, Baffoni L, Gaggìa F, Biavati B. Validation of candidate reference genes in Bifidobacterium adolescentis for gene expression normalization. Anaerobe 2014; 27:34-9. [DOI: 10.1016/j.anaerobe.2014.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 03/10/2014] [Accepted: 03/11/2014] [Indexed: 10/25/2022]
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