99901
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The Proline Variant of the W[F/L/M][T/S]R Cyclic Di-GMP Binding Motif Suppresses Dependence on Signal Association for Regulator Function. J Bacteriol 2017; 199:JB.00344-17. [PMID: 28652300 DOI: 10.1128/jb.00344-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 06/19/2017] [Indexed: 12/21/2022] Open
Abstract
Vibrio vulnificus is an estuarine bacterium and potent opportunistic human pathogen. It enters the food chain by asymptomatically colonizing a variety of marine organisms, most notably oysters. Expression of the brp-encoded extracellular polysaccharide, which enhances cell-surface adherence, is regulated by cyclic di-GMP (c-di-GMP) and the activator BrpT. The Vibrio cholerae and Vibrio parahaemolyticus homologs VpsT and CpsQ, directly bind c-di-GMP via a novel W[F/L/M][T/S]R motif, and c-di-GMP binding is absolutely required for activity. Notably, BrpT belongs to a distinct subclass of VpsT-like regulators that harbor a proline in the third position of the c-di-GMP binding motif (WLPR), and the impact of this change on activity is unknown. We show that the brp locus is organized as two linked operons with BrpT specifically binding to promoters upstream of brpA and brpH Expression data and structural modeling suggested that BrpT might be less dependent on c-di-GMP binding for activity than VpsT or CpsQ. We show that the affinity of BrpT for c-di-GMP is low and that signal binding is not a requisite for BrpT function. Furthermore, a BrpT mutant engineered to carry a canonical WLTR motif (BrpTP124T) bound c-di-GMP with high affinity and its activity was now c-di-GMP dependent. Conversely, introduction of the WLPR motif into VpsT suppressed its dependence on c-di-GMP for activity. This is the first demonstration of reduced dependence on signal association for regulator function within this motif family. Thus, BrpT defines a new class of VpsT-like transcriptional regulators, and the WLPR motif variant may similarly liberate the activity of other subclass members.IMPORTANCE A Vibrio genome may encode nearly 100 proteins that make, break, and bind c-di-GMP, underscoring its central role in the physiology of these bacteria. The activity of the biofilm regulators VpsT of V. cholerae and CpsQ of V. parahaemolyticus is regulated by the direct binding of c-di-GMP via a novel W[F/L/M][T/S]R motif. The V. vulnificus homolog, BrpT, bears an unusual WLPR variant and remains active at low intracellular c-di-GMP levels. This suggests that the WLPR motif may also liberate the activity of other members of this subclass. A single point mutation at the 3rd position of the motif was sufficient to moderate dependence on c-di-GMP binding for activator function, highlighting the simplicity with which complex bacterial signaling networks can be rewired.
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99902
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Kumar R, Jangir PK, Das J, Taneja B, Sharma R. Genome Analysis of Staphylococcus capitis TE8 Reveals Repertoire of Antimicrobial Peptides and Adaptation Strategies for Growth on Human Skin. Sci Rep 2017; 7:10447. [PMID: 28874737 PMCID: PMC5585272 DOI: 10.1038/s41598-017-11020-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 08/17/2017] [Indexed: 11/13/2022] Open
Abstract
Staphylococcus capitis TE8 was isolated from skin surface of a healthy human foot, and exhibited a strong antibacterial activity against Gram-positive bacteria, including Staphylococcus aureus. Whole genome sequence of S. capitis TE8 was obtained by shotgun and paired-end pyrosequencing with a coverage of 109-fold. The draft genome contains 2,516,639 bp in 8 scaffolds with 209 total contigs. The genome contains 2319 protein coding sequences, 58 tRNA and 3 rRNA. Genome sequence analysis revealed 4 distinct gene loci with the ability to encode antimicrobial peptides: (i) an epidermicin gene cluster; (ii) a gallidermin gene cluster; (iii) a gene cluster encoding six phenol soluble modulin (PSM) β-type peptides (PSMβ1-β6) and (iv) an additional gene that belonged to PSMβ family and encoded a 44 residues long peptide, HTP2388. Synthetic peptides with sequence identical to seven PSMβ-like peptides i.e. PSMβ1-β6 and peptide HTP2388 showed antibacterial activity. Genome sequence also revealed genes for adhesins, intracellular adhesins, osmoadaptation, oxidative and acid stress tolerance possibly responsible for initial attachment, colonization and survival of S. capitis TE8 on human skin. Comparative genome analysis revealed presence of a gamut of genes in S. capitis strains in comparison to Staphylococcus epidermidis and Staphylococcus caprae indicating towards their possible role in better adaptation and survival on human skin.
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Affiliation(s)
- Rohit Kumar
- CSIR-Institute of Genomics and Integrative Biology, Council of Scientific and Industrial Research (CSIR), New Delhi, India.,Food Corporation of India, Ludhiana, India
| | - Pramod Kumar Jangir
- CSIR-Institute of Genomics and Integrative Biology, Council of Scientific and Industrial Research (CSIR), New Delhi, India.,Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre of the Hungarian Academy of Sciences, Szeged, 6726, Hungary
| | - Jhumki Das
- CSIR-Institute of Genomics and Integrative Biology, Council of Scientific and Industrial Research (CSIR), New Delhi, India
| | - Bhupesh Taneja
- CSIR-Institute of Genomics and Integrative Biology, Council of Scientific and Industrial Research (CSIR), New Delhi, India. .,Academy of Scientific and Innovative Research (AcSIR), New Delhi, India.
| | - Rakesh Sharma
- CSIR-Institute of Genomics and Integrative Biology, Council of Scientific and Industrial Research (CSIR), New Delhi, India. .,Academy of Scientific and Innovative Research (AcSIR), New Delhi, India.
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99903
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Hydrogen peroxide dynamics in subcellular compartments of malaria parasites using genetically encoded redox probes. Sci Rep 2017; 7:10449. [PMID: 28874682 PMCID: PMC5585161 DOI: 10.1038/s41598-017-10093-8] [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: 06/13/2017] [Accepted: 08/03/2017] [Indexed: 11/23/2022] Open
Abstract
Redox balance is essential for the survival, growth and multiplication of malaria parasites and oxidative stress is involved in the mechanism of action of many antimalarial drugs. Hydrogen peroxide (H2O2) plays an important role in redox signalling and pathogen-host cell interactions. For monitoring intra- and subcellular redox events, highly sensitive and specific probes are required. Here, we stably expressed the ratiometric H2O2 redox sensor roGFP2-Orp1 in the cytosol and the mitochondria of Plasmodium falciparum (P. falciparum) NF54-attB blood-stage parasites and evaluated its sensitivity towards oxidative stress, selected antimalarial drugs, and novel lead compounds. In both compartments, the sensor showed reproducible sensitivity towards H2O2 in the low micromolar range and towards antimalarial compounds at pharmacologically relevant concentrations. Upon short-term exposure (4 h), artemisinin derivatives, quinine and mefloquine impacted H2O2 levels in mitochondria, whereas chloroquine and a glucose-6-phosphate dehydrogenase (G6PD) inhibitor affected the cytosol; 24 h exposure to arylmethylamino steroids and G6PD inhibitors revealed oxidation of mitochondria and cytosol, respectively. Genomic integration of an H2O2 sensor expressed in subcellular compartments of P. falciparum provides the basis for studying complex parasite-host cell interactions or drug effects with spatio-temporal resolution while preserving cell integrity, and sets the stage for high-throughput approaches to identify antimalarial agents perturbing redox equilibrium.
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99904
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Mechanisms of Resistance to Folate Pathway Inhibitors in Burkholderia pseudomallei: Deviation from the Norm. mBio 2017; 8:mBio.01357-17. [PMID: 28874476 PMCID: PMC5587915 DOI: 10.1128/mbio.01357-17] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The trimethoprim and sulfamethoxazole combination, co-trimoxazole, plays a vital role in the treatment of Burkholderia pseudomallei infections. Previous studies demonstrated that the B. pseudomallei BpeEF-OprC efflux pump confers widespread trimethoprim resistance in clinical and environmental isolates, but this is not accompanied by significant resistance to co-trimoxazole. Using the excluded select-agent strain B. pseudomallei Bp82, we now show that in vitro acquired trimethoprim versus co-trimoxazole resistance is mainly mediated by constitutive BpeEF-OprC expression due to bpeT mutations or by BpeEF-OprC overexpression due to bpeS mutations. Mutations in bpeT affect the carboxy-terminal effector-binding domain of the BpeT LysR-type activator protein. Trimethoprim resistance can also be mediated by dihydrofolate reductase (FolA) target mutations, but this occurs rarely unless BpeEF-OprC is absent. BpeS is a transcriptional regulator that is 62% identical to BpeT. Mutations affecting the BpeS DNA-binding or carboxy-terminal effector-binding domains result in constitutive BpeEF-OprC overexpression, leading to trimethoprim and sulfamethoxazole efflux and thus to co-trimoxazole resistance. The majority of laboratory-selected co-trimoxazole-resistant mutants often also contain mutations in folM, encoding a pterin reductase. Genetic analyses of these mutants established that both bpeS mutations and folM mutations contribute to co-trimoxazole resistance, although the exact role of folM remains to be determined. Mutations affecting bpeT, bpeS, and folM are common in co-trimoxazole-resistant clinical isolates, indicating that mutations affecting these genes are clinically significant. Co-trimoxazole resistance in B. pseudomallei is a complex phenomenon, which may explain why resistance to this drug is rare in this bacterium. Burkholderia pseudomallei causes melioidosis, a tropical disease that is difficult to treat. The bacterium’s resistance to antibiotics limits therapeutic options. The paucity of orally available drugs further complicates therapy. The oral drug of choice is co-trimoxazole, a combination of trimethoprim and sulfamethoxazole. These antibiotics target two distinct enzymes, FolA (dihydrofolate reductase) and FolP (dihydropteroate synthase), in the bacterial tetrahydrofolate biosynthetic pathway. Although co-trimoxazole resistance is minimized due to two-target inhibition, bacterial resistance due to folA and folP mutations does occur. Co-trimoxazole resistance in B. pseudomallei is rare and has not yet been studied. Co-trimoxazole resistance in this bacterium employs a novel strategy involving differential regulation of BpeEF-OprC efflux pump expression that determines the drug resistance profile. Contributing are mutations affecting folA, but not folP, and folM, a folate pathway-associated gene whose function is not yet well understood and which has not been previously implicated in folate inhibitor resistance in clinical isolates.
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99905
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Kalule JB, Fortuin S, Calder B, Robberts L, Keddy KH, Nel AJM, Garnett S, Nicol M, Warner DF, Soares NC, Blackburn JM. Proteomic comparison of three clinical diarrhoeagenic drug-resistant Escherichia coli isolates grown on CHROMagar™STEC media. J Proteomics 2017; 180:25-35. [PMID: 28887208 DOI: 10.1016/j.jprot.2017.09.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 08/21/2017] [Accepted: 09/02/2017] [Indexed: 02/06/2023]
Abstract
Shiga-toxin-producing Escherichia coli (STEC) and enteropathogenic Escherichia coli (EPEC) are key diarrhoea-causing foodborne pathogens. We used proteomics to characterize the virulence and antimicrobial resistance protein profiles of three clinical pathogenic E. coli isolates (two EPEC [one resistant to ciprofloxacin] and one STEC) cultured on CHROMagar™STEC solid media after minimal laboratory passage. We identified 4767 unique peptides from 1630 protein group across all three clinical E. coli strains. Label-free proteomic analysis allowed the identification of virulence and drug resistance proteins that were unique to each of the clinical isolates compared in this study. The B subunit of Shiga toxin, ToxB, was uniquely detected in the STEC strain while several other virulence factors including SheA, OmpF, OmpC and OmpX were significantly more abundant in the STEC strain. The ciprofloxacin resistant EPEC isolate possessed reduced levels of key virulence proteins compared to the ciprofloxacin susceptible EPEC and STEC strains. Parallel reaction monitoring assays validated the presence of biologically relevant proteins across biologically-replicated cultures. Propagation of clinical isolates on a relevant solid medium followed by mass spectrometry analysis represents a convenient means to quantify virulence factors and drug resistance determinants that might otherwise be lost through extensive in vitro passage in enteropathogenic bacteria. SIGNIFICANCE Through the use of quantitative proteomics, we have characterized the virulence and antimicrobial resistance attributes of three clinically isolated, pathogenic E. coli strains cultured on solid media. Our results provide new, quantitative data on the expressed proteomes of these tellurite-resistant, diarrhoeagenic E. coli strains and reveal a subset of antimicrobial resistance and virulence proteins that are differentially abundant between these clinical strains. Our quantitative proteomics-based approach should thus have applicability in microbiological diagnostic labs for the identification of pathogenic/drug resistant E. coli in the future.
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Affiliation(s)
- John Bosco Kalule
- Division of Medical Microbiology, Department of Pathology, University of Cape Town, South Africa
| | - Suereta Fortuin
- Division of Chemical & Systems Biology, Department of Integrative Biomedical Sciences, University of Cape Town, Cape Town, South Africa
| | - Bridget Calder
- Division of Chemical & Systems Biology, Department of Integrative Biomedical Sciences, University of Cape Town, Cape Town, South Africa
| | - Lourens Robberts
- Division of Medical Microbiology, Department of Pathology, University of Cape Town, South Africa
| | - Karen H Keddy
- Bacteriology Division, Centre for Enteric Diseases, National Institute for Communicable Diseases, Sandringham, Johannesburg, South Africa; Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Andrew J M Nel
- Division of Chemical & Systems Biology, Department of Integrative Biomedical Sciences, University of Cape Town, Cape Town, South Africa
| | - Shaun Garnett
- Division of Chemical & Systems Biology, Department of Integrative Biomedical Sciences, University of Cape Town, Cape Town, South Africa
| | - Mark Nicol
- Division of Medical Microbiology, Department of Pathology, University of Cape Town, South Africa; Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, South Africa
| | - Digby F Warner
- Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, South Africa; MRC/NHLS/UCT Molecular Mycobacteriology Research Unit, DST/NRF Centre of Excellence for Biomedical TB Research, Division of Medical Microbiology, Department of Pathology, University of Cape Town, South Africa
| | - Nelson C Soares
- Division of Chemical & Systems Biology, Department of Integrative Biomedical Sciences, University of Cape Town, Cape Town, South Africa.
| | - Jonathan M Blackburn
- Division of Chemical & Systems Biology, Department of Integrative Biomedical Sciences, University of Cape Town, Cape Town, South Africa; Institute of Infectious Disease and Molecular Medicine (IDM), University of Cape Town, South Africa.
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99906
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Zinc depletion promotes apoptosis-like death in drug-sensitive and antimony-resistance Leishmania donovani. Sci Rep 2017; 7:10488. [PMID: 28874760 PMCID: PMC5585245 DOI: 10.1038/s41598-017-10041-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 07/25/2017] [Indexed: 12/28/2022] Open
Abstract
Micronutrients are essential for survival and growth for all the organisms including pathogens. In this manuscript, we report that zinc (Zn) chelator N,N,N’,N’-tetrakis(2-pyridinylmethyl)-1,2-ethylenediamine (TPEN) affects growth and viability of intracellular pathogen Leishmania donovani (LD) by a concentration and time dependent manner. Simultaneous addition of zinc salt reverses the effect of TPEN. Further experiments provide evidence of apoptosis-like death of the parasite due to Zn-depletion. TPEN treatment enhances caspase-like activity suggesting increase in apoptosis-like events in LD. Specific inhibitors of cathepsin B and Endoclease G block TPEN-induced leishmanial death. Evidences show involvement of reactive oxygen species (ROS) potentially of extra-mitochondrial origin in TPEN-induced LD death. Pentavalent antimonials remained the prime source of treatment against leishmaniasis for several decades; however, antimony-resistant Leishmania is now common source of the disease. We also reveal that Zn-depletion can promote apoptosis-like death in antimony-resistant parasites. In summary, we present a new finding about the role of zinc in the survival of drug sensitive and antimony-resistant LD.
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99907
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Cyclic Di-GMP and VpsR Induce the Expression of Type II Secretion in Vibrio cholerae. J Bacteriol 2017; 199:JB.00106-17. [PMID: 28674069 DOI: 10.1128/jb.00106-17] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 06/09/2017] [Indexed: 12/23/2022] Open
Abstract
Vibrio cholerae is a human pathogen that alternates between growth in environmental reservoirs and infection of human hosts, causing severe diarrhea. The second messenger cyclic di-GMP (c-di-GMP) mediates this transition by controlling a wide range of functions, such as biofilms, virulence, and motility. Here, we report that c-di-GMP induces expression of the extracellular protein secretion (eps) gene cluster, which encodes the type II secretion system (T2SS) in V. cholerae Analysis of the eps genes confirmed the presence of two promoters located upstream of epsC, the first gene in the operon, one of which is induced by c-di-GMP. This induction is directly mediated by the c-di-GMP-binding transcriptional activator VpsR. Increased expression of the eps operon did not impact secretion of extracellular toxin or biofilm formation but did increase expression of the pseudopilin protein EpsG on the cell surface.IMPORTANCE Type II secretion systems (T2SSs) are the primary molecular machines by which Gram-negative bacteria secrete proteins and protein complexes that are folded and assembled in the periplasm. The substrates of T2SSs include extracellular factors, such as proteases and toxins. Here, we show that the widely conserved second messenger cyclic di-GMP (c-di-GMP) upregulates expression of the eps genes encoding the T2SS in the pathogen V. cholerae via the c-di-GMP-dependent transcription factor VpsR.
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99908
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Metabolism Dealing with Thermal Degradation of NAD + in the Hyperthermophilic Archaeon Thermococcus kodakarensis. J Bacteriol 2017; 199:JB.00162-17. [PMID: 28652302 DOI: 10.1128/jb.00162-17] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 06/13/2017] [Indexed: 11/20/2022] Open
Abstract
NAD+ is an important cofactor for enzymatic oxidation reactions in all living organisms, including (hyper)thermophiles. However, NAD+ is susceptible to thermal degradation at high temperatures. It can thus be expected that (hyper)thermophiles harbor mechanisms that maintain in vivo NAD+ concentrations and possibly remove and/or reuse undesirable degradation products of NAD+ Here we confirmed that at 85°C, thermal degradation of NAD+ results mostly in the generation of nicotinamide and ADP-ribose, the latter known to display toxicity by spontaneously linking to proteins. The hyperthermophilic archaeon Thermococcus kodakarensis possesses a putative ADP-ribose pyrophosphatase (ADPR-PPase) encoded by the TK2284 gene. ADPR-PPase hydrolyzes ADP-ribose to ribose 5-phosphate (R5P) and AMP. The purified recombinant TK2284 protein exhibited activity toward ADP-ribose as well as ADP-glucose. Kinetic analyses revealed a much higher catalytic efficiency toward ADP-ribose, suggesting that ADP-ribose was the physiological substrate. To gain insight into the physiological function of TK2284, a TK2284 gene disruption strain was constructed and examined. Incubation of NAD+ in the cell extract of the mutant strain at 85°C resulted in higher ADP-ribose accumulation and lower AMP production compared with those in experiments with the host strain cell extract. The mutant strain also exhibited lower cell yield and specific growth rates in a synthetic amino acid medium compared with those of the host strain. The results obtained here suggest that the ADPR-PPase in T. kodakarensis is responsible for the cleavage of ADP-ribose to R5P and AMP, providing a means to utilize the otherwise dead-end product of NAD+ breakdown.IMPORTANCE Hyperthermophilic microorganisms living under high temperature conditions should have mechanisms that deal with the degradation of thermolabile molecules. NAD+ is an important cofactor for enzymatic oxidation reactions and is susceptible to thermal degradation to ADP-ribose and nicotinamide. Here we show that an ADP-ribose pyrophosphatase homolog from the hyperthermophilic archaeon Thermococcus kodakarensis converts the detrimental ADP-ribose to ribose 5-phosphate and AMP, compounds that can be directed to central carbon metabolism. This physiological role for ADP-ribose pyrophosphatases might be universal in hyperthermophiles, as their homologs are widely distributed among both hyperthermophilic bacteria and archaea.
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99909
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McGowin CL, Totten PA. The Unique Microbiology and Molecular Pathogenesis of Mycoplasma genitalium. J Infect Dis 2017; 216:S382-S388. [PMID: 28838077 DOI: 10.1093/infdis/jix172] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mycoplasma genitalium is increasingly appreciated as a common cause of sexually transmitted disease syndromes, including urethritis in men and cervicitis, endometritis, pelvic inflammatory disease, and possibly preterm birth, tubal factor infertility, and ectopic pregnancy in women. Despite these disease associations, which parallel those of Chlamydia trachomatis and Neisseria gonorrhoeae, the mechanisms by which this pathogen elicits inflammation, causes cellular damage, and persists in its only natural host (humans) are unique and are not fully understood. The purpose of this review is to briefly provide a historical background on the discovery, microbiology, and recognition of M. genitalium as a pathogen, and then summarize the recent advances in our understanding of the molecular biology and pathogenesis of this unique urogenital organism. Collectively, the basic scientific discussions herein should provide a framework for understanding the clinical and epidemiological outcomes described in the accompanying articles in this supplemental issue.
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Affiliation(s)
- Chris L McGowin
- Departments of 1 Microbiology, Immunology, and Parasitology.,Internal Medicine (Section of Infectious Diseases), Louisiana State University Health Sciences Center, New Orleans
| | - Patricia A Totten
- Departments of 3 Medicine (Division of Infectious Diseases).,Global Health (Pathobiology Interdisciplinary Program), University of Washington, Seattle
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99910
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Matsuda Y, Hopkinson BM, Nakajima K, Dupont CL, Tsuji Y. Mechanisms of carbon dioxide acquisition and CO 2 sensing in marine diatoms: a gateway to carbon metabolism. Philos Trans R Soc Lond B Biol Sci 2017; 372:20160403. [PMID: 28717013 PMCID: PMC5516112 DOI: 10.1098/rstb.2016.0403] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/31/2017] [Indexed: 01/03/2023] Open
Abstract
Diatoms are one of the most successful marine eukaryotic algal groups, responsible for up to 20% of the annual global CO2 fixation. The evolution of a CO2-concentrating mechanism (CCM) allowed diatoms to overcome a number of serious constraints on photosynthesis in the marine environment, particularly low [CO2]aq in seawater relative to concentrations required by the CO2 fixing enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO), which is partly due to the slow diffusion rate of CO2 in water and a limited CO2 formation rate from [Formula: see text] in seawater. Diatoms use two alternative strategies to take up dissolved inorganic carbon (DIC) from the environment: one primarily relies on the direct uptake of [Formula: see text] through plasma-membrane type solute carrier (SLC) 4 family [Formula: see text] transporters and the other is more reliant on passive diffusion of CO2 formed by an external carbonic anhydrase (CA). Bicarbonate taken up into the cytoplasm is most likely then actively transported into the chloroplast stroma by SLC4-type transporters on the chloroplast membrane system. Bicarbonate in the stroma is converted into CO2 only in close proximity to RubisCO preventing unnecessary CO2 leakage. CAs play significant roles in mobilizing DIC as it is progressively moved towards the site of fixation. However, the evolutionary types and subcellular locations of CAs are not conserved between different diatoms, strongly suggesting that this DIC mobilization strategy likely evolved multiple times with different origins. By contrast, the recent discovery of the thylakoid luminal θ-CA indicates that the strategy to supply CO2 to RubisCO in the pyrenoid may be very similar to that of green algae, and strongly suggests convergent coevolution in CCM function of the thylakoid lumen not only among diatoms but among eukaryotic algae in general. In this review, both experimental and corresponding theoretical models of the diatom CCMs are discussed.This article is part of the themed issue 'The peculiar carbon metabolism in diatoms'.
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Affiliation(s)
- Yusuke Matsuda
- Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, Hyogo 669-1337, Japan
| | - Brian M Hopkinson
- Department of Marine Sciences, University of Georgia, Athens, GA 30602, USA
| | - Kensuke Nakajima
- Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, Hyogo 669-1337, Japan
| | | | - Yoshinori Tsuji
- Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, Hyogo 669-1337, Japan
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99911
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Chen JC, Chang CF, Hsu DW, Shu JC, Chen HY, Chen CY, Lu CY, Chen CC. Temporal regulation of σ B by partner-switching mechanism at a distinct growth stage in Bacillus cereus. Int J Med Microbiol 2017; 307:521-532. [PMID: 28919098 DOI: 10.1016/j.ijmm.2017.09.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 08/15/2017] [Accepted: 09/04/2017] [Indexed: 12/01/2022] Open
Abstract
The alternative transcription factor σB in Bacillus cereus governs the transcription of a number of genes that confer protection against general stress. This transcription factor is regulated by protein-protein interactions among RsbV, RsbW, σB, RsbY, RsbM and RsbK, all encoded in the sigB cluster. Among these regulatory proteins, RsbV, RsbW and σB comprise a partner-switching mechanism. Under normal conditions, σB remains inactive by associating with anti-sigma factor RsbW, which prevents σB from binding to the core RNA polymerase. During environmental stress, RsbK activates RsbY to hydrolyze phosphorylated RsbV, and the dephosphorylated RsbV then sequesters RsbW to liberate σB from RsbW. Although the σB partner-switching module is thought to be the core mechanism for σB regulation, the actual protein-protein interactions among these three proteins in the cell remain to be investigated. In the current study, we show that RsbW and RsbV form a long-lived complex under transient stress treatment, resulting in high persistent expression of RsbV, RsbW and σB from mid-log phase to stationary phase. Full sequestration of RsbW by excess RsbV and increased RsbW:RsbV complex stability afforded by cellular ADP contribute to the prolonged activation of σB. Interestingly, the high expression levels of RsbV, RsbW and σB were dramatically decreased beginning from the transition stage to the stationary phase. Thus, protein interactions among σB partner-switching components are required for the continued induction of σB during environmental stress in the log phase and significant down-regulation of σB is observed in the stationary phase. Our data show that σB is temporally regulated in B. cereus.
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Affiliation(s)
- Jung-Chi Chen
- Department of Biotechnology, National Kaohsiung Normal University, 62 Shenjhong Road, Yanchao District, Kaohsiung 82444, Taiwan
| | - Chuan-Fu Chang
- Department of Biotechnology, National Kaohsiung Normal University, 62 Shenjhong Road, Yanchao District, Kaohsiung 82444, Taiwan
| | - Duen-Wei Hsu
- Department of Biotechnology, National Kaohsiung Normal University, 62 Shenjhong Road, Yanchao District, Kaohsiung 82444, Taiwan
| | - Jwu-Ching Shu
- Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan County 333, Taiwan
| | - Hong-Yi Chen
- Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan County 333, Taiwan
| | - Chien-Yen Chen
- Department of Earth and Environmental Sciences, National Chung Cheng University, 168 University Road, Min-Hsiung, Chiayi 62102, Taiwan
| | - Chi-Yu Lu
- Department of Biochemistry, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Chien-Cheng Chen
- Department of Biotechnology, National Kaohsiung Normal University, 62 Shenjhong Road, Yanchao District, Kaohsiung 82444, Taiwan.
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99912
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The TORC2-Dependent Signaling Network in the Yeast Saccharomyces cerevisiae. Biomolecules 2017; 7:biom7030066. [PMID: 28872598 PMCID: PMC5618247 DOI: 10.3390/biom7030066] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 08/25/2017] [Accepted: 08/28/2017] [Indexed: 12/21/2022] Open
Abstract
To grow, eukaryotic cells must expand by inserting glycerolipids, sphingolipids, sterols, and proteins into their plasma membrane, and maintain the proper levels and bilayer distribution. A fungal cell must coordinate growth with enlargement of its cell wall. In Saccharomyces cerevisiae, a plasma membrane-localized protein kinase complex, Target of Rapamicin (TOR) complex-2 (TORC2) (mammalian ortholog is mTORC2), serves as a sensor and master regulator of these plasma membrane- and cell wall-associated events by directly phosphorylating and thereby stimulating the activity of two types of effector protein kinases: Ypk1 (mammalian ortholog is SGK1), along with a paralog (Ypk2); and, Pkc1 (mammalian ortholog is PKN2/PRK2). Ypk1 is a central regulator of pathways and processes required for plasma membrane lipid and protein homeostasis, and requires phosphorylation on its T-loop by eisosome-associated protein kinase Pkh1 (mammalian ortholog is PDK1) and a paralog (Pkh2). For cell survival under various stresses, Ypk1 function requires TORC2-mediated phosphorylation at multiple sites near its C terminus. Pkc1 controls diverse processes, especially cell wall synthesis and integrity. Pkc1 is also regulated by Pkh1- and TORC2-dependent phosphorylation, but, in addition, by interaction with Rho1-GTP and lipids phosphatidylserine (PtdSer) and diacylglycerol (DAG). We also describe here what is currently known about the downstream substrates modulated by Ypk1-mediated and Pkc1-mediated phosphorylation.
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99913
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Caliskan N, Wohlgemuth I, Korniy N, Pearson M, Peske F, Rodnina MV. Conditional Switch between Frameshifting Regimes upon Translation of dnaX mRNA. Mol Cell 2017; 66:558-567.e4. [PMID: 28525745 DOI: 10.1016/j.molcel.2017.04.023] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 03/07/2017] [Accepted: 04/27/2017] [Indexed: 12/16/2022]
Abstract
Ribosome frameshifting during translation of bacterial dnaX can proceed via different routes, generating a variety of distinct polypeptides. Using kinetic experiments, we show that -1 frameshifting predominantly occurs during translocation of two tRNAs bound to the slippery sequence codons. This pathway depends on a stem-loop mRNA structure downstream of the slippery sequence and operates when aminoacyl-tRNAs are abundant. However, when aminoacyl-tRNAs are in short supply, the ribosome switches to an alternative frameshifting pathway that is independent of a stem-loop. Ribosome stalling at a vacant 0-frame A-site codon results in slippage of the P-site peptidyl-tRNA, allowing for -1-frame decoding. When the -1-frame aminoacyl-tRNA is lacking, the ribosomes switch into -2 frame. Quantitative mass spectrometry shows that the -2-frame product is synthesized in vivo. We suggest that switching between frameshifting routes may enrich gene expression at conditions of aminoacyl-tRNA limitation.
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MESH Headings
- Bacterial Proteins/biosynthesis
- Bacterial Proteins/genetics
- DNA Polymerase III/biosynthesis
- DNA Polymerase III/genetics
- Escherichia coli/enzymology
- Escherichia coli/genetics
- Frameshifting, Ribosomal
- Gene Expression Regulation, Bacterial
- Gene Expression Regulation, Enzymologic
- Kinetics
- Mutation
- Nucleic Acid Conformation
- RNA, Bacterial/chemistry
- RNA, Bacterial/genetics
- RNA, Bacterial/metabolism
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Transfer, Amino Acyl/chemistry
- RNA, Transfer, Amino Acyl/genetics
- RNA, Transfer, Amino Acyl/metabolism
- Spectrometry, Mass, Electrospray Ionization
- Structure-Activity Relationship
- Tandem Mass Spectrometry
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Affiliation(s)
- Neva Caliskan
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Ingo Wohlgemuth
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Natalia Korniy
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Michael Pearson
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Frank Peske
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Marina V Rodnina
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
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99914
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Abstract
Bacteria use flagella to move toward nutrients, find its host, or retract from toxic substances. Because bacterial flagellum is one of the ligands that activate the host innate immune system, its synthesis should be tightly regulated during host infection, which is largely unknown. Here, we report that a bacterial leader mRNA from the mgtCBR virulence operon in the intracellular pathogen Salmonella enterica serovar Typhimurium binds to the fljB coding region of mRNAs in the fljBA operon encoding the FljB phase 2 flagellin, a main component of bacterial flagella and the FljA repressor for the FliC phase 1 flagellin, and degrades fljBA mRNAs in an RNase E-dependent fashion during infection. A nucleotide substitution of the fljB flagellin gene that prevents the mgtC leader RNA-mediated down-regulation increases the fljB-encoded flagellin synthesis, leading to a hypermotile phenotype inside macrophages. Moreover, the fljB nucleotide substitution renders Salmonella hypervirulent, indicating that FljB-based motility must be compromised in the phagosomal compartment where Salmonella resides. This suggests that this pathogen promotes pathogenicity by producing a virulence protein and limits locomotion by a trans-acting leader RNA from the same virulence gene during infection.
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99915
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Dharra R, Talwar S, Singh Y, Gupta R, Cirillo JD, Pandey AK, Kulharia M, Mehta PK. Rational design of drug-like compounds targeting Mycobacterium marinum MelF protein. PLoS One 2017; 12:e0183060. [PMID: 28873466 PMCID: PMC5584760 DOI: 10.1371/journal.pone.0183060] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 07/28/2017] [Indexed: 11/19/2022] Open
Abstract
The mycobacterial mel2 locus (mycobacterial enhanced infection locus, Rv1936-1941) is Mycobacterium marinum and M. tuberculosis specific, which can withstand reactive oxygen species (ROS) and reactive nitrogen species (RNS) induced stress. A library of over a million compounds was screened using in silico virtual ligand screening (VLS) to identify inhibitors against the modeled structure of MelF protein expressed by melF of mel2 locus so that M. marinum’s ability to withstand ROS/RNS stress could be reduced. The top ranked 1000 compounds were further screened to identify 178 compounds to maximize the scaffold diversity by manually evaluating the interaction of each compound with the target site. M. marinum melF was cloned, expressed and purified as maltose binding protein (MBP)-tagged recombinant protein in Escherichia coli. After establishing the flavin dependent oxidoreductase activity of MelF (~ 84 kDa), the inhibitors were screened for the inhibition of enzyme activity of whole cell lysate (WCL) and the purified MelF. Amongst these, 16 compounds could significantly inhibit the enzyme activity of purified MelF. For the six best inhibitory compounds, the minimal inhibitory concentration (MIC) was determined to be 3.4–19.4 μM and 13.5–38.8 μM for M. marinum and M. tuberculosis, respectively. Similarly, the minimal bactericidal concentration (MBC) was determined to be 6.8–38.8 μM and 27–38.8 μM against M. marinum and M. tuberculosis, respectively. One compound each in combination with isoniazid (INH) also showed synergistic inhibitory effect against M. marinum and M. tuberculosis with no cytotoxicity in HeLa cells. Interestingly, these inhibitors did not display any non-specific protein-structure destabilizing effect. Such inhibitors targeting the anti-ROS/RNS machinery may facilitate the efficient killing of replicating and nonreplicating mycobacteria inside the host cells.
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Affiliation(s)
- Renu Dharra
- Centre for Biotechnology, Maharshi Dayanand University (MDU), Rohtak, India
| | - Sakshi Talwar
- Translational Health Science and Technology Institute (THSTI), Faridabad, India
| | - Yogesh Singh
- Department of Microbiology, University of Delhi South Campus, New Delhi, India
| | - Rani Gupta
- Department of Microbiology, University of Delhi South Campus, New Delhi, India
| | - Jeffrey D. Cirillo
- Department of Microbial and Molecular Pathogenesis, Texas A&M Health Science Center, College Station, Texas, United States of America
| | - Amit K. Pandey
- Translational Health Science and Technology Institute (THSTI), Faridabad, India
| | - Mahesh Kulharia
- School of Basic and Applied Science, Central University of Punjab, Bathinda, India
- * E-mail: (MK); (PKM)
| | - Promod K. Mehta
- Centre for Biotechnology, Maharshi Dayanand University (MDU), Rohtak, India
- * E-mail: (MK); (PKM)
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99916
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Lai RZ, Han XS, Dahlquist FW, Parkinson JS. Paradoxical enhancement of chemoreceptor detection sensitivity by a sensory adaptation enzyme. Proc Natl Acad Sci U S A 2017; 114:E7583-E7591. [PMID: 28827352 PMCID: PMC5594695 DOI: 10.1073/pnas.1709075114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A sensory adaptation system that tunes chemoreceptor sensitivity enables motile Escherichia coli cells to track chemical gradients with high sensitivity over a wide dynamic range. Sensory adaptation involves feedback control of covalent receptor modifications by two enzymes: CheR, a methyltransferase, and CheB, a methylesterase. This study describes a CheR function that opposes the signaling consequences of its catalytic activity. In the presence of CheR, a variety of mutant serine chemoreceptors displayed up to 40-fold enhanced detection sensitivity to chemoeffector stimuli. This response enhancement effect did not require the known catalytic activity of CheR, but did involve a binding interaction between CheR and receptor molecules. Response enhancement was maximal at low CheR:receptor stoichiometry and quantitative analyses argued against a reversible binding interaction that simply shifts the ON-OFF equilibrium of receptor signaling complexes. Rather, a short-lived CheR binding interaction appears to promote a long-lasting change in receptor molecules, either a covalent modification or conformation that enhances their response to attractant ligands.
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Affiliation(s)
- Run-Zhi Lai
- Biology Department, University of Utah, Salt Lake City, UT 84112
| | - Xue-Sheng Han
- Biology Department, University of Utah, Salt Lake City, UT 84112
| | - Frederick W Dahlquist
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106
| | - John S Parkinson
- Biology Department, University of Utah, Salt Lake City, UT 84112;
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99917
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Sonowal R, Swimm A, Sahoo A, Luo L, Matsunaga Y, Wu Z, Bhingarde JA, Ejzak EA, Ranawade A, Qadota H, Powell DN, Capaldo CT, Flacker JM, Jones RM, Benian GM, Kalman D. Indoles from commensal bacteria extend healthspan. Proc Natl Acad Sci U S A 2017; 114:E7506-E7515. [PMID: 28827345 PMCID: PMC5594673 DOI: 10.1073/pnas.1706464114] [Citation(s) in RCA: 123] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Multiple studies have identified conserved genetic pathways and small molecules associated with extension of lifespan in diverse organisms. However, extending lifespan does not result in concomitant extension in healthspan, defined as the proportion of time that an animal remains healthy and free of age-related infirmities. Rather, mutations that extend lifespan often reduce healthspan and increase frailty. The question arises as to whether factors or mechanisms exist that uncouple these processes and extend healthspan and reduce frailty independent of lifespan. We show that indoles from commensal microbiota extend healthspan of diverse organisms, including Caenorhabditis elegans, Drosophila melanogaster, and mice, but have a negligible effect on maximal lifespan. Effects of indoles on healthspan in worms and flies depend upon the aryl hydrocarbon receptor (AHR), a conserved detector of xenobiotic small molecules. In C. elegans, indole induces a gene expression profile in aged animals reminiscent of that seen in the young, but which is distinct from that associated with normal aging. Moreover, in older animals, indole induces genes associated with oogenesis and, accordingly, extends fecundity and reproductive span. Together, these data suggest that small molecules related to indole and derived from commensal microbiota act in diverse phyla via conserved molecular pathways to promote healthy aging. These data raise the possibility of developing therapeutics based on microbiota-derived indole or its derivatives to extend healthspan and reduce frailty in humans.
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Affiliation(s)
- Robert Sonowal
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Alyson Swimm
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Anusmita Sahoo
- Emory Vaccine Center, Emory University, Atlanta, GA 30329
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322
- Yerkes National Primate Research Center, Lawrenceville, GA 30043
| | - Liping Luo
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322
| | - Yohei Matsunaga
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Ziqi Wu
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Jui A Bhingarde
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Elizabeth A Ejzak
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Ayush Ranawade
- Department of Biology, McMaster University, Hamilton, ON, Canada L8S 4K1
| | - Hiroshi Qadota
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Domonica N Powell
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
- Immunology and Molecular Pathogenesis Graduate Program, Emory University School of Medicine, Atlanta, GA 30322
| | | | - Jonathan M Flacker
- Division of Geriatric Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Rhienallt M Jones
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322
| | - Guy M Benian
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322
| | - Daniel Kalman
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322;
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99918
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Microbial production of poly-γ-glutamic acid. World J Microbiol Biotechnol 2017; 33:173. [DOI: 10.1007/s11274-017-2338-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 08/30/2017] [Indexed: 10/18/2022]
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99919
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Improving Fab' fragment retention in an autonucleolytic Escherichia coli strain by swapping periplasmic nuclease translocation signal from OmpA to DsbA. Biotechnol Lett 2017; 39:1865-1873. [PMID: 28875244 PMCID: PMC5674116 DOI: 10.1007/s10529-017-2425-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 08/22/2017] [Indexed: 12/27/2022]
Abstract
Objectives To reduce unwanted Fab’ leakage from an autonucleolytic Escherichia coli strain, which co-expresses OmpA-signalled Staphylococcal nuclease and Fab’ fragment in the periplasm, by substituting in Serratial nuclease and the DsbA periplasm translocation signal as alternatives. Results We attempted to genetically fuse a nuclease from Serratia marcescens to the OmpA signal peptide but plasmid construction failed, possibly due to toxicity of the resultant nuclease. Combining Serratial nuclease to the DsbA signal peptide was successful. The strain co-expressing this nuclease and periplasmic Fab’ grew in complex media and exhibited nuclease activity detectable by DNAse agar plate but its growth in defined medium was retarded. Fab’ coexpression with Staphylococcal nuclease fused to the DsbA signal peptide resulted in cells exhibiting nuclease activity and growth in defined medium. In cultivation to high cell density in a 5 l bioreactor, DsbA-fused Staphylococcal nuclease co-expression coincided with reduced Fab’ leakage relative to the original autonucleolytic Fab’ strain with OmpA-fused staphylococcal nuclease. Conclusions We successfully rescued Fab’ leakage back to acceptable levels and established a basis for future investigation of the linkage between periplasmic nuclease expression and leakage of co-expressed periplasmic Fab’ fragment to the surrounding growth media.
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99920
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Al-Yousef HM, Ahmed AF, Al-Shabib NA, Laeeq S, Khan RA, Rehman MT, Alsalme A, Al-Ajmi MF, Khan MS, Husain FM. Onion Peel Ethylacetate Fraction and Its Derived Constituent Quercetin 4'- O-β-D Glucopyranoside Attenuates Quorum Sensing Regulated Virulence and Biofilm Formation. Front Microbiol 2017; 8:1675. [PMID: 28928721 PMCID: PMC5591837 DOI: 10.3389/fmicb.2017.01675] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 08/18/2017] [Indexed: 12/04/2022] Open
Abstract
The resistance and pathogenesis of bacteria could be related to their ability to sense and respond to population density, termed quorum sensing (QS). Inhibition of the QS system is considered as a novel strategy for the development of antipathogenic agents, especially for combating drug-resistant bacterial infections. In the present study, the anti-QS activity of Onion peel ethylacetate fraction (ONE) was tested against Chromobacterium violaceum CV12472 and Pseudomonas aeruginosa PAO1. ONE inhibit the QS-mediated virulence factors production such as violacein in C. violaceum and elastase, pyocyanin in P. aeruginosa. Further, the treatment with sub-MICs of ONE significantly inhibited the QS-mediated biofilm formation, EPS (Extracellular polymeric substances) production and swarming motility. Further, quercetin 4′-O-β-D glucopyranoside (QGP) was isolated from ONE and its anti-QS potential was confirmed after observing significant inhibition of QS-controlled virulence factors such as violacein, elastase, pyocyanin and biofilm formation in test pathogens. Molecular docking analysis predicted that QGP should be able to bind at the active sites of Vfr and LasR, and if so blocks the entry of active sites in Vfr and LasR.
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Affiliation(s)
- Hanan M Al-Yousef
- Department of Pharmacognosy, College of Pharmacy, King Saud UniversityRiyadh, Saudi Arabia
| | - Atallah F Ahmed
- Department of Pharmacognosy, College of Pharmacy, King Saud UniversityRiyadh, Saudi Arabia
| | - Nasser A Al-Shabib
- Department of Food Science and Nutrition, Faculty of Food and Agricultural Sciences, King Saud UniversityRiyadh, Saudi Arabia
| | - Sameen Laeeq
- Department of Applied Chemistry, Faculty of Engineering and Technology, Aligarh Muslim UniversityAligarh, India
| | - Rais A Khan
- Department of Chemistry, College of Sciences, King Saud UniversityRiyadh, Saudi Arabia
| | - Md T Rehman
- Department of Pharmacognosy, College of Pharmacy, King Saud UniversityRiyadh, Saudi Arabia
| | - Ali Alsalme
- Department of Chemistry, College of Sciences, King Saud UniversityRiyadh, Saudi Arabia
| | - Mohamed F Al-Ajmi
- Department of Pharmacognosy, College of Pharmacy, King Saud UniversityRiyadh, Saudi Arabia
| | - Mohammad S Khan
- Department of Agricultural Microbiology, Aligarh Muslim UniversityAligarh, India
| | - Fohad M Husain
- Department of Food Science and Nutrition, Faculty of Food and Agricultural Sciences, King Saud UniversityRiyadh, Saudi Arabia
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99921
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Sehnert B, Burkhardt H, Finzel S, Dübel S, Voll RE. The sneaking ligand approach for cell type-specific modulation of intracellular signalling pathways. Clin Immunol 2017; 186:14-20. [PMID: 28867254 DOI: 10.1016/j.clim.2017.08.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 08/30/2017] [Indexed: 11/30/2022]
Abstract
Small molecules interfering with intracellular signalling pathways are used in the treatment of multiple diseases including RA. However, small molecules usually affect signalling in most cell types, not only in those which need to be targeted. This general inhibition of signalling pathways causes often adverse effects, which could be avoided by cell type-specific inhibitors. For cell-type specific modulation of signal transduction, we developed the sneaking ligand fusion proteins (SLFPs). SLFPs contain three domains: (1) the binding domain mediating cell type-specific targeting and endocytosis; (2) the endosomal release sequence releasing the effector domain into the cytoplasm; (3) the effector domain modulating signalling. Using our SLFP NF-kappaB inhibitor termed SLC1 we demonstrated that cell-type-specific modulation of intracellular signalling pathways is feasible, that endothelial NF-kappaB activation is critical for arthritis and peritonitis and that SLFPs help to identify disease-relevant pathways in defined cell types. Hence, SLFPs may improve risk-benefit ratios of therapeutic interventions.
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Affiliation(s)
- Bettina Sehnert
- Department of Rheumatology and Clinical Immunology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
| | - Harald Burkhardt
- Division of Rheumatology, Department of Internal Medicine II, Fraunhofer IME-Project-Group Translational Medicine and Pharmacology, Johann Wolfgang Goethe University Frankfurt am Main, Frankfurt am Main, Germany
| | - Stephanie Finzel
- Department of Rheumatology and Clinical Immunology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Stefan Dübel
- Institute of Biochemistry, Biotechnology and Bioinformatics, Technical University Braunschweig, Braunschweig, Germany
| | - Reinhard E Voll
- Department of Rheumatology and Clinical Immunology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
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99922
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Sicard JF, Le Bihan G, Vogeleer P, Jacques M, Harel J. Interactions of Intestinal Bacteria with Components of the Intestinal Mucus. Front Cell Infect Microbiol 2017; 7:387. [PMID: 28929087 PMCID: PMC5591952 DOI: 10.3389/fcimb.2017.00387] [Citation(s) in RCA: 279] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 08/18/2017] [Indexed: 12/19/2022] Open
Abstract
The human gut is colonized by a variety of large amounts of microbes that are collectively called intestinal microbiota. Most of these microbial residents will grow within the mucus layer that overlies the gut epithelium and will act as the first line of defense against both commensal and invading microbes. This mucus is essentially formed by mucins, a family of highly glycosylated protein that are secreted by specialize cells in the gut. In this Review, we examine how commensal members of the microbiota and pathogenic bacteria use mucus to their advantage to promote their growth, develop biofilms and colonize the intestine. We also discuss how mucus-derived components act as nutrient and chemical cues for adaptation and pathogenesis of bacteria and how bacteria can influence the composition of the mucus layer.
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Affiliation(s)
- Jean-Félix Sicard
- Centre de Recherche en Infectiologie Porcine et Aviaire, Faculté de Médecine Vétérinaire, Université de MontréalSaint-Hyacinthe, QC, Canada
| | - Guillaume Le Bihan
- Centre de Recherche en Infectiologie Porcine et Aviaire, Faculté de Médecine Vétérinaire, Université de MontréalSaint-Hyacinthe, QC, Canada
| | - Philippe Vogeleer
- Centre de Recherche en Infectiologie Porcine et Aviaire, Faculté de Médecine Vétérinaire, Université de MontréalSaint-Hyacinthe, QC, Canada
| | - Mario Jacques
- Regroupement de Recherche Pour un Lait de Qualité Optimale (Op+Lait), Faculté de Médecine Vétérinaire, Université de MontréalSaint-Hyacinthe, QC, Canada
| | - Josée Harel
- Centre de Recherche en Infectiologie Porcine et Aviaire, Faculté de Médecine Vétérinaire, Université de MontréalSaint-Hyacinthe, QC, Canada
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99923
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Abstract
The coordination of group behaviors in bacteria is accomplished via the cell-cell signaling process called quorum sensing. Vibrios have historically been models for studying bacterial communication due to the diverse and remarkable behaviors controlled by quorum sensing in these bacteria, including bioluminescence, type III and type VI secretion, biofilm formation, and motility. Here, we discuss the Vibrio LuxR/HapR family of proteins, the master global transcription factors that direct downstream gene expression in response to changes in cell density. These proteins are structurally similar to TetR transcription factors but exhibit distinct biochemical and genetic features from TetR that determine their regulatory influence on the quorum sensing gene network. We review here the gene groups regulated by LuxR/HapR and quorum sensing and explore the targets that are common and unique among Vibrio species.
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99924
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Kato A, Ueda S, Oshima T, Inukai Y, Okajima T, Igarashi M, Eguchi Y, Utsumi R. Characterization of H-box region mutants of WalK inert to the action of waldiomycin in Bacillus subtilis. J GEN APPL MICROBIOL 2017; 63:212-221. [PMID: 28674376 DOI: 10.2323/jgam.2016.10.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The WalK/WalR two-component system is essential for cell wall metabolism and thus for cell growth in Bacillus subtilis. Waldiomycin was previously isolated as an antibiotic that targeted WalK, the cognate histidine kinase (HK) of the response regulator, WalR, in B. subtilis. To gain further insights into the action of waldiomycin on WalK and narrow down its site of action, mutations were introduced in the H-box region, a well-conserved motif of the bacterial HKs of WalK. The half-maximal inhibitory concentrations (IC50s) of waldiomycin against purified WalK protein with triple substitutions in the H-box region, R377M/R378M/S385A and R377M/R378M/R389M, were 26.4 and 55.1 times higher than that of the wild-type protein, respectively, indicating that these residues of WalK are crucial for the inhibitory effect of waldiomycin on its kinase activity. Surprisingly, this antibiotic severely affected cell growth in a minimum inhibitory concentration (MIC) assay, but not transcription of WalR-regulated genes or cell morphology in B. subtilis strains that harbored the H-box triple substitutions on the bacterial chromosome. We hypothesized that waldiomycin targets other HKs as well, which may, in turn, sensitize B. subtilis cells with the H-box triple mutant alleles of the walK gene to waldiomycin. Waldiomycin inhibited other HKs such as PhoR and ResE, and, to a lesser extent, CitS, whose H-box region is less conserved. These results suggest that waldiomycin perturbs multiple cellular processes in B. subtilis by targeting the H-box region of WalK and other HKs.
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Affiliation(s)
- Akinori Kato
- Department of Advanced Bioscience, Graduate School of Agriculture, Kindai University
| | - Shuhei Ueda
- Department of Advanced Bioscience, Graduate School of Agriculture, Kindai University
| | - Taku Oshima
- Graduate School of Biological Sciences, Nara Institute of Science and Technology
| | - Yoichi Inukai
- Department of Advanced Bioscience, Graduate School of Agriculture, Kindai University
| | | | | | - Yoko Eguchi
- Department of Science and Technology on Food Safety, Faculty of Biology-Oriented Science and Technology, Kindai University
| | - Ryutaro Utsumi
- Department of Advanced Bioscience, Graduate School of Agriculture, Kindai University
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99925
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Calabrese AN, Jackson SM, Jones LN, Beckstein O, Heinkel F, Gsponer J, Sharples D, Sans M, Kokkinidou M, Pearson AR, Radford SE, Ashcroft AE, Henderson PJF. Topological Dissection of the Membrane Transport Protein Mhp1 Derived from Cysteine Accessibility and Mass Spectrometry. Anal Chem 2017; 89:8844-8852. [PMID: 28726379 PMCID: PMC5588088 DOI: 10.1021/acs.analchem.7b01310] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Accepted: 07/20/2017] [Indexed: 01/01/2023]
Abstract
Cys accessibility and quantitative intact mass spectrometry (MS) analyses have been devised to study the topological transitions of Mhp1, the membrane protein for sodium-linked transport of hydantoins from Microbacterium liquefaciens. Mhp1 has been crystallized in three forms (outward-facing open, outward-facing occluded with substrate bound, and inward-facing open). We show that one natural cysteine residue, Cys327, out of three, has an enhanced solvent accessibility in the inward-facing (relative to the outward-facing) form. Reaction of the purified protein, in detergent, with the thiol-reactive N-ethylmalemide (NEM), results in modification of Cys327, suggesting that Mhp1 adopts predominantly inward-facing conformations. Addition of either sodium ions or the substrate 5-benzyl-l-hydantoin (L-BH) does not shift this conformational equilibrium, but systematic co-addition of the two results in an attenuation of labeling, indicating a shift toward outward-facing conformations that can be interpreted using conventional enzyme kinetic analyses. Such measurements can afford the Km for each ligand as well as the stoichiometry of ion-substrate-coupled conformational changes. Mutations that perturb the substrate binding site either result in the protein being unable to adopt outward-facing conformations or in a global destabilization of structure. The methodology combines covalent labeling, mass spectrometry, and kinetic analyses in a straightforward workflow applicable to a range of systems, enabling the interrogation of changes in a protein's conformation required for function at varied concentrations of substrates, and the consequences of mutations on these conformational transitions.
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Affiliation(s)
| | | | | | - Oliver Beckstein
- Department of Physics, Arizona State University , Tempe, Arizona 85287-1504, United States
| | - Florian Heinkel
- Centre for High-Throughput Biology, University of British Columbia , Vancouver, British Columbia, Canada V6T 1Z4
| | - Joerg Gsponer
- Centre for High-Throughput Biology, University of British Columbia , Vancouver, British Columbia, Canada V6T 1Z4
| | | | - Marta Sans
- Hamburg Centre for Ultrafast Imaging, Institute for Nanostructure and Solid State Physics, Universität Hamburg , Hamburg 22761, Germany
| | - Maria Kokkinidou
- Hamburg Centre for Ultrafast Imaging, Institute for Nanostructure and Solid State Physics, Universität Hamburg , Hamburg 22761, Germany
| | - Arwen R Pearson
- Hamburg Centre for Ultrafast Imaging, Institute for Nanostructure and Solid State Physics, Universität Hamburg , Hamburg 22761, Germany
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99926
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Escherichia coli responds to environmental changes using enolasic degradosomes and stabilized DicF sRNA to alter cellular morphology. Proc Natl Acad Sci U S A 2017; 114:E8025-E8034. [PMID: 28874523 DOI: 10.1073/pnas.1703731114] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Escherichia coli RNase E is an essential enzyme that forms multicomponent ribonucleolytic complexes known as "RNA degradosomes." These complexes consist of four major components: RNase E, PNPase, RhlB RNA helicase, and enolase. However, the role of enolase in the RNase E/degradosome is not understood. Here, we report that presence of enolase in the RNase E/degradosome under anaerobic conditions regulates cell morphology, resulting in Ecoli MG1655 cell filamentation. Under anaerobic conditions, enolase bound to the RNase E/degradosome stabilizes the small RNA (sRNA) DicF, i.e., the inhibitor of the cell division gene ftsZ, through chaperon protein Hfq-dependent regulation. RNase E/enolase distribution changes from membrane-associated patterns under aerobic to diffuse patterns under anaerobic conditions. When the enolase-RNase E/degradosome interaction is disrupted, the anaerobically induced characteristics disappear. We provide a mechanism by which Ecoli uses enolase-bound degradosomes to switch from rod-shaped to filamentous form in response to anaerobiosis by regulating RNase E subcellular distribution, RNase E enzymatic activity, and the stability of the sRNA DicF required for the filamentous transition. In contrast to Ecoli nonpathogenic strains, pathogenic Ecoli strains predominantly have multiple copies of sRNA DicF in their genomes, with cell filamentation previously being linked to bacterial pathogenesis. Our data suggest a mechanism for bacterial cell filamentation during infection under anaerobic conditions.
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99927
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Abstract
Invasive bacterial pathogens can capture host plasminogen (Plg) and allow it to form plasmin. This process is of medical importance as surface-bound plasmin promotes bacterial spread by cleaving tissue components and favors immune evasion by degrading opsonins. In Staphylococcus aureus, Plg binding is in part mediated by cell surface fibronectin-binding proteins (FnBPs), but the underlying molecular mechanism is not known. Here, we use single-cell and single-molecule techniques to demonstrate that FnBPs capture Plg by a sophisticated activation mechanism involving fibrinogen (Fg), another ligand found in the blood. We show that while FnBPs bind to Plg through weak (∼200-pN) molecular bonds, direct interaction of the adhesins with Fg through the high-affinity dock, lock, and latch mechanism dramatically increases the strength of the FnBP-Plg bond (up to ∼2,000 pN). Our results point to a new model in which the binding of Fg triggers major conformational changes in the FnBP protein, resulting in the buried Plg-binding domains being projected and exposed away from the cell surface, thereby promoting strong interactions with Plg. This study demonstrated a previously unidentified role for a ligand-binding interaction by a staphylococcal cell surface protein, i.e., changing the protein orientation to activate a cryptic biological function. Staphylococcus aureus captures human plasminogen (Plg) via cell wall fibronectin-binding proteins (FnBPs), but the underlying molecular mechanism is not known. Here we show that the forces involved in the interaction between Plg and FnBPs on the S. aureus surface are weak. However, we discovered that binding of fibrinogen to FnBPs dramatically strengthens the FnBP-Plg bond, therefore revealing an unanticipated role for Fg in the capture of Plg by S. aureus. These experiments favor a model where Fg-induced conformational changes in FnBPs promote their interaction with Plg. This work uncovers a previously undescribed activation mechanism for a staphylococcal surface protein, whereby ligand-binding elicits a cryptic biological function.
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99928
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Parallel Evolution of Group B Streptococcus Hypervirulent Clonal Complex 17 Unveils New Pathoadaptive Mutations. mSystems 2017; 2:mSystems00074-17. [PMID: 28904998 PMCID: PMC5585690 DOI: 10.1128/msystems.00074-17] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 08/10/2017] [Indexed: 12/21/2022] Open
Abstract
The incidence of group B Streptococcus (GBS) neonatal disease continues to be a significant cause of concern worldwide. Strains belonging to clonal complex 17 (CC17) are the most frequently responsible for GBS infections in neonates, especially among late-onset disease cases. Therefore, we undertook the largest genomic study of GBS CC17 strains to date to decipher the genetic bases of their remarkable colonization and infection ability. We show that crucial functions involved in different steps of the colonization or infection process of GBS are distinctly mutated during the adaptation of CC17 to the human host. In particular, our results implicate the CovRS two-component regulator of virulence in the differentiation between carriage- and disease-associated isolates. Not only does this work raise important implications for the ongoing development of a vaccine against GBS but might also drive the discovery of key functions for GBS adaptation and pathogenesis that have been overlooked until now. Group B Streptococcus (GBS) is a commensal of the gastrointestinal and genitourinary tracts, while a prevailing cause of neonatal disease worldwide. Of the various clonal complexes (CCs), CC17 is overrepresented in GBS-infected newborns for reasons that are still largely unknown. Here, we report a comprehensive genomic analysis of 626 CC17 isolates collected worldwide, identifying the genetic traits behind their successful adaptation to humans and the underlying differences between carriage and clinical strains. Comparative analysis with 923 GBS genomes belonging to CC1, CC19, and CC23 revealed that the evolution of CC17 is distinct from that of other human-adapted lineages and recurrently targets functions related to nucleotide and amino acid metabolism, cell adhesion, regulation, and immune evasion. We show that the most distinctive features of disease-specific CC17 isolates were frequent mutations in the virulence-associated CovS and Stk1 kinases, underscoring the crucial role of the entire CovRS regulatory pathway in modulating the pathogenicity of GBS. Importantly, parallel and convergent evolution of major components of the bacterial cell envelope, such as the capsule biosynthesis operon, the pilus, and Rib, reflects adaptation to host immune pressures and should be taken into account in the ongoing development of a GBS vaccine. The presence of recurrent targets of evolution not previously implicated in virulence also opens the way for uncovering new functions involved in host colonization and GBS pathogenesis. IMPORTANCE The incidence of group B Streptococcus (GBS) neonatal disease continues to be a significant cause of concern worldwide. Strains belonging to clonal complex 17 (CC17) are the most frequently responsible for GBS infections in neonates, especially among late-onset disease cases. Therefore, we undertook the largest genomic study of GBS CC17 strains to date to decipher the genetic bases of their remarkable colonization and infection ability. We show that crucial functions involved in different steps of the colonization or infection process of GBS are distinctly mutated during the adaptation of CC17 to the human host. In particular, our results implicate the CovRS two-component regulator of virulence in the differentiation between carriage- and disease-associated isolates. Not only does this work raise important implications for the ongoing development of a vaccine against GBS but might also drive the discovery of key functions for GBS adaptation and pathogenesis that have been overlooked until now. Author Video: An author video summary of this article is available.
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99929
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Lima JLDC, Alves LR, Paz JNPD, Rabelo MA, Maciel MAV, Morais MMCD. Analysis of biofilm production by clinical isolates of Pseudomonas aeruginosa from patients with ventilator-associated pneumonia. Rev Bras Ter Intensiva 2017; 29:310-316. [PMID: 28876402 PMCID: PMC5632973 DOI: 10.5935/0103-507x.20170039] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 04/13/2017] [Indexed: 11/20/2022] Open
Abstract
Objective To phenotypically evaluate biofilm production by Pseudomonas
aeruginosa clinically isolated from patients with
ventilator-associated pneumonia. Methods Twenty clinical isolates of P. aeruginosa were analyzed, 19
of which were from clinical samples of tracheal aspirate, and one was from a
bronchoalveolar lavage sample. The evaluation of the capacity of P.
aeruginosa to produce biofilm was verified using two
techniques, one qualitative and the other quantitative. Results The qualitative technique showed that only 15% of the isolates were
considered biofilm producers, while the quantitative technique showed that
75% of the isolates were biofilm producers. The biofilm isolates presented
the following susceptibility profile: 53.3% were multidrug-resistant, and
46.7% were multidrug-sensitive. Conclusion The quantitative technique was more effective than the qualitative technique
for the detection of biofilm production. For the bacterial population
analyzed, biofilm production was independent of the susceptibility profile
of the bacteria, demonstrating that the therapeutic failure could be related
to biofilm production, as it prevented the destruction of the bacteria
present in this structure, causing complications of pneumonia associated
with mechanical ventilation, including extrapulmonary infections, and making
it difficult to treat the infection.
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Affiliation(s)
- Jailton Lobo da Costa Lima
- Programa de Pós-graduação em Medicina Tropical, Centro de Ciências da Saúde, Universidade Federal de Pernambuco - Recife (PE), Brasil
| | - Lilian Rodrigues Alves
- Programa de Pós-graduação em Medicina Tropical, Centro de Ciências da Saúde, Universidade Federal de Pernambuco - Recife (PE), Brasil
| | - Jussyêgles Niedja Pereira da Paz
- Programa de Pós-graduação em Medicina Tropical, Centro de Ciências da Saúde, Universidade Federal de Pernambuco - Recife (PE), Brasil
| | - Marcelle Aquino Rabelo
- Programa de Pós-graduação em Medicina Tropical, Centro de Ciências da Saúde, Universidade Federal de Pernambuco - Recife (PE), Brasil
| | - Maria Amélia Vieira Maciel
- Programa de Pós-graduação em Medicina Tropical, Centro de Ciências da Saúde, Universidade Federal de Pernambuco - Recife (PE), Brasil
| | - Marcia Maria Camargo de Morais
- Programa de Pós-graduação em Biologia Celular e Molecular Aplicada, Instituto de Ciências Biológicas, Universidade de Pernambuco - Recife (PE), Brasil
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99930
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Engineering a riboswitch-based genetic platform for the self-directed evolution of acid-tolerant phenotypes. Nat Commun 2017; 8:411. [PMID: 28871084 PMCID: PMC5583362 DOI: 10.1038/s41467-017-00511-w] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 07/05/2017] [Indexed: 12/12/2022] Open
Abstract
Environmental pH is a fundamental signal continuously directing the metabolism and behavior of living cells. Programming the precise cellular response toward environmental pH is, therefore, crucial for engineering cells for increasingly sophisticated functions. Herein, we engineer a set of riboswitch-based pH-sensing genetic devices to enable the control of gene expression according to differential environmental pH. We next develop a digital pH-sensing system to utilize the analogue-sensing behavior of these devices for high-resolution recording of host cell exposure to discrete external pH levels. The application of this digital pH-sensing system is demonstrated in a genetic program that autonomously regulated the evolutionary engineering of host cells for improved tolerance to a broad spectrum of organic acids, a valuable phenotype for metabolic engineering and bioremediation applications. Cells are exposed to shifts in environmental pH, which direct their metabolism and behavior. Here the authors design pH-sensing riboswitches to create a gene expression program, digitalize the system to respond to a narrow pH range and apply it to evolve host cells with improved tolerance to a variety of organic acids.
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99931
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Amlinger L, Hoekzema M, Wagner EGH, Koskiniemi S, Lundgren M. Fluorescent CRISPR Adaptation Reporter for rapid quantification of spacer acquisition. Sci Rep 2017; 7:10392. [PMID: 28871175 PMCID: PMC5583386 DOI: 10.1038/s41598-017-10876-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 08/16/2017] [Indexed: 12/26/2022] Open
Abstract
CRISPR-Cas systems are adaptive prokaryotic immune systems protecting against horizontally transferred DNA or RNA such as viruses and other mobile genetic elements. Memory of past invaders is stored as spacers in CRISPR loci in a process called adaptation. Here we developed a novel assay where spacer integration results in fluorescence, enabling detection of memory formation in single cells and quantification of as few as 0.05% cells with expanded CRISPR arrays in a bacterial population. Using this fluorescent CRISPR Adaptation Reporter (f-CAR), we quantified adaptation of the two CRISPR arrays of the type I-E CRISPR-Cas system in Escherichia coli, and confirmed that more integration events are targeted to CRISPR-II than to CRISPR-I. The f-CAR conveniently analyzes and compares many samples, allowing new insights into adaptation. For instance, we show that in an E. coli culture the majority of acquisition events occur in late exponential phase.
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Affiliation(s)
- Lina Amlinger
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Mirthe Hoekzema
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - E Gerhart H Wagner
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Sanna Koskiniemi
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Magnus Lundgren
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden.
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99932
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Aynapudi J, El-Rami F, Ge X, Stone V, Zhu B, Kitten T, Xu P. Involvement of signal peptidase I in Streptococcus sanguinis biofilm formation. MICROBIOLOGY-SGM 2017; 163:1306-1318. [PMID: 28869408 PMCID: PMC5817204 DOI: 10.1099/mic.0.000516] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Biofilm accounts for 65–80 % of microbial infections in humans. Considerable evidence links biofilm formation by oral microbiota to oral disease and consequently systemic infections. Streptococcus sanguinis, a Gram-positive bacterium, is one of the most abundant species of the oral microbiota and it contributes to biofilm development in the oral cavity. Due to its altered biofilm formation, we investigated a biofilm mutant, ΔSSA_0351, that is deficient in type I signal peptidase (SPase) in this study. Although the growth curve of the ΔSSA_0351 mutant showed no significant difference from that of the wild-type strain SK36, biofilm assays using both microtitre plate assay and confocal laser scanning microscopy (CLSM) confirmed a sharp reduction in biofilm formation in the mutant compared to the wild-type strain and the paralogous mutant ΔSSA_0849. Scanning electron microscopy (SEM) revealed remarkable differences in the cell surface morphologies and chain length of the ΔSSA_0351 mutant compared with those of the wild-type strain. Transcriptomic and proteomic assays using RNA sequencing and mass spectrometry, respectively, were conducted on the ΔSSA_0351 mutant to evaluate the functional impact of SPase on biofilm formation. Subsequently, bioinformatics analysis revealed a number of proteins that were differentially regulated in the ΔSSA_0351 mutant, narrowing down the list of SPase substrates involved in biofilm formation to lactate dehydrogenase (SSA_1221) and a short-chain dehydrogenase (SSA_0291). With further experimentation, this list defined the link between SSA_0351-encoded SPase, cell wall biosynthesis and biofilm formation.
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Affiliation(s)
- Jessica Aynapudi
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, VA, USA.,Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA.,Present address: School of Dentistry, Virginia Commonwealth University, Richmond, VA, USA
| | - Fadi El-Rami
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, VA, USA.,Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA
| | - Xiuchun Ge
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, VA, USA
| | - Victoria Stone
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, VA, USA
| | - Bin Zhu
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, VA, USA
| | - Todd Kitten
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, VA, USA.,Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA
| | - Ping Xu
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, VA, USA.,Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA
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99933
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Wang GY, Ma F, Wang HH, Xu XL, Zhou GH. Characterization of Extracellular Polymeric Substances Produced byPseudomonas fragiUnder Air and Modified Atmosphere Packaging. J Food Sci 2017; 82:2151-2157. [DOI: 10.1111/1750-3841.13832] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 06/29/2017] [Accepted: 07/05/2017] [Indexed: 11/30/2022]
Affiliation(s)
- Guang-Yu Wang
- Key Laboratory of Meat Processing and Quality Control; Nanjing Agricultural Univ.; Nanjing Jiangsu China
| | - Fang Ma
- College of Veterinary Medicine; Nanjing Agriculture Univ.; Nanjing, Jiangsu 210095 P. R. China
| | - Hu-Hu Wang
- Key Laboratory of Meat Processing and Quality Control; Nanjing Agricultural Univ.; Nanjing Jiangsu China
| | - Xing-Lian Xu
- Key Laboratory of Meat Processing and Quality Control; Nanjing Agricultural Univ.; Nanjing Jiangsu China
| | - Guang-hong Zhou
- Collaborative Innovation Center of Food Safety and Nutrition, College of Food Science and Technology; Nanjing Agricultural Univ.; Nanjing Jiangsu China
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99934
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Hansmeier N, Miskiewicz K, Elpers L, Liss V, Hensel M, Sterzenbach T. Functional expression of the entire adhesiome of Salmonella enterica serotype Typhimurium. Sci Rep 2017; 7:10326. [PMID: 28871183 PMCID: PMC5583245 DOI: 10.1038/s41598-017-10598-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 08/10/2017] [Indexed: 12/21/2022] Open
Abstract
Adhesins are crucial virulence factors of pathogenic bacteria involved in colonization, transmission and pathogenesis. Many bacterial genomes contain the information for a surprisingly large number of diverse adhesive structures. One prominent example is the invasive and facultative intracellular pathogen Salmonella enterica with an adhesiome of up to 20 adhesins. Such large repertoire of adhesins contributes to colonization of a broad range of host species and may allow adaptation to various environments within the host, as well as in non-host environments. For S. enterica, only few members of the adhesiome are functionally expressed under laboratory conditions, and accordingly the structural and functional understanding of the majority of adhesins is sparse. We have devised a simple and versatile approach to functionally express all adhesins of S. enterica serotype Typhimurium, either within Salmonella or within heterologous hosts such as Escherichia coli. We demonstrate the surface expression of various so far cryptic adhesins and show ultrastructural features using atomic force microscopy and transmission electron microscopy. In summary, we report for the first time the expression of the entire adhesiome of S. enterica serotype Typhimurium.
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Affiliation(s)
- Nicole Hansmeier
- Abteilung Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, Barbarastr. 11, 49076, Osnabrück, Germany
| | - Katarzyna Miskiewicz
- Abteilung Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, Barbarastr. 11, 49076, Osnabrück, Germany
| | - Laura Elpers
- Abteilung Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, Barbarastr. 11, 49076, Osnabrück, Germany
| | - Viktoria Liss
- Abteilung Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, Barbarastr. 11, 49076, Osnabrück, Germany
| | - Michael Hensel
- Abteilung Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, Barbarastr. 11, 49076, Osnabrück, Germany.
| | - Torsten Sterzenbach
- Abteilung Mikrobiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, Barbarastr. 11, 49076, Osnabrück, Germany.
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99935
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Moscatello NJ, Pfeifer BA. Yersiniabactin metal binding characterization and removal of nickel from industrial wastewater. Biotechnol Prog 2017; 33:1548-1554. [DOI: 10.1002/btpr.2542] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 08/21/2017] [Indexed: 01/18/2023]
Affiliation(s)
- Nicholas J. Moscatello
- Dept. of Chemical and Biological Engineering; University at Buffalo, The State University of New York; Buffalo NY 14260
| | - Blaine A. Pfeifer
- Dept. of Chemical and Biological Engineering; University at Buffalo, The State University of New York; Buffalo NY 14260
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99936
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Barasuol BM, Guizzo JA, Fegan JE, Martínez-Martínez S, Rodríguez-Ferri EF, Gutiérrez-Martín CB, Kreutz LC, Schryvers AB, Frandoloso R. New insights about functional and cross-reactive properties of antibodies generated against recombinant TbpBs of Haemophilus parasuis. Sci Rep 2017; 7:10377. [PMID: 28871190 PMCID: PMC5583350 DOI: 10.1038/s41598-017-10627-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 08/10/2017] [Indexed: 12/20/2022] Open
Abstract
Vaccines have become fundamental in the control and elimination of Glässer Disease, a systemic disease of pigs caused by Haemophilus parasuis. The classic vaccines available for prevention of this infection were developed without a robust knowledge about host immunological mechanisms. In this study, we demonstrated the presence of cross-reactive epitopes on both the N-lobe and C-lobe of variants of transferrin binding protein B (TbpBs) expressed on the surface of 6 virulent serovars of H. parasuis. Antibodies against TbpB-derived antigens were capable of increasing the phagocytic capacity of neutrophils and were also capable of blocking porcine transferrin from binding to TbpB. Surprisingly, none of the pig or mice antisera from animals immunized with TbpB-derived antigens mixed with Montanide IMS 2215 VG PR adjuvant were able to activate the classical complement pathway (CCP). In contrast, antisera from mice immunized with TbpB-derived antigens adjuvanted with Freund’s adjuvants or Montanide Gel 01 were able to activate the CCP and kill H. parasuis. Our results demonstrate that the type of adjuvant can modulate the functional response induced by TbpB-derived antigens. Based on these results, we propose that a properly formulated TbpB-based vaccine may elicit a functional protective antibody response with broad cross-reactivity against heterologous strains of H. parasuis.
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Affiliation(s)
- Bibiana Martins Barasuol
- Laboratory of Microbiology and Advanced Immunology, Faculty of Agronomy and Veterinary Medicine, University of Passo Fundo, Passo Fundo, 99052-900, Brazil
| | - João Antônio Guizzo
- Laboratory of Microbiology and Advanced Immunology, Faculty of Agronomy and Veterinary Medicine, University of Passo Fundo, Passo Fundo, 99052-900, Brazil
| | - Jamie Elisabeth Fegan
- Department of Microbiology & Infectious Diseases, Faculty of Medicine, University of Calgary, Calgary, T2N 4N1, Alberta, Canada
| | - Sonia Martínez-Martínez
- Unidad de Microbiología e Inmunología, Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, 24007, León, Spain
| | - Elías Fernando Rodríguez-Ferri
- Unidad de Microbiología e Inmunología, Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, 24007, León, Spain
| | - César Bernardo Gutiérrez-Martín
- Unidad de Microbiología e Inmunología, Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, 24007, León, Spain
| | - Luiz Carlos Kreutz
- Laboratory of Microbiology and Advanced Immunology, Faculty of Agronomy and Veterinary Medicine, University of Passo Fundo, Passo Fundo, 99052-900, Brazil
| | - Anthony Bernard Schryvers
- Department of Microbiology & Infectious Diseases, Faculty of Medicine, University of Calgary, Calgary, T2N 4N1, Alberta, Canada
| | - Rafael Frandoloso
- Laboratory of Microbiology and Advanced Immunology, Faculty of Agronomy and Veterinary Medicine, University of Passo Fundo, Passo Fundo, 99052-900, Brazil.
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99937
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Neji S, Hadrich I, Trabelsi H, Abbes S, Cheikhrouhou F, Sellami H, Makni F, Ayadi A. Virulence factors, antifungal susceptibility and molecular mechanisms of azole resistance among Candida parapsilosis complex isolates recovered from clinical specimens. J Biomed Sci 2017; 24:67. [PMID: 28870262 PMCID: PMC5582387 DOI: 10.1186/s12929-017-0376-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 08/30/2017] [Indexed: 01/12/2023] Open
Abstract
Background The aim of this study was to determine the biofilm formation, the extracellular enzymatic activities of 182 clinical isolates of the Candida parapsilosis complex. Methods Molecular identification of the C. parapsilosis species complex was performed using PCR RFLP of SADH gene and PCR sequencing of ITS region. The susceptibility of ours isolates to antifungal agents and molecular mechanisms underlying azole resistance were evaluated. Results 63.5% of C. parapsilosis were phospholipase positive with moderate activity for the majority of strains. None of the C. metapsilosis or C. orthopsilosis isolates was able to produce phospholipase. Higher caseinase activities were detected in C. parapsilosis (Pz = 0.5 ± 0.18) and C. orthopsilosis (Pz = 0.49 ± 0.07) than in C. metapsilosis isolates (Pz = 0.72 ± 0.1). 96.5% of C. parapsilosis strains and all isolates of C. metapsilosis and C. orthopsilosis produced gelatinase. All the strains possessed the ability to show haemolysis on blood agar. C. metapsilosis exhibited the low haemolysin production with statistical significant differences compared to C. parapsilosis and C. orthopsilosis. The biofilm forming ability of C. parapsilosis was highly strain dependent with important heterogeneity, which was less evident with both C. orthopsilosis and C. metapsilosis. Some C. parapsilosis isolates met the criterion for susceptible dose dependent to fluconazole (10.91%), itraconazole (16.36%) and voriconazole (7.27%). Moreover, 5.45% and 1.82% of C. parapsilosis isolates were respectively resistant to fluconazole and voriconazole. All strains of C. metapsilosis and C. orthopsilosis were susceptible to azoles; and isolates of all three species exhibited 100% of susceptibility to caspofungin, amphotericin B and 5-flucytosine. Conclusions A combination of molecular mechanisms, including the overexpression of ERG11, and genes encoding efflux pumps (CDR1, MDR1, and MRR1) were involved in azole resistance in C. parapsilosis.
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Affiliation(s)
- Sourour Neji
- Laboratory of Parasitology - Mycology, UH Habib Bourguiba, Sfax, Tunisia.,Laboratory of Fungal and Parasitic Molecular Biology, School of Medicine, University of Sfax, Sfax, Tunisia
| | - Ines Hadrich
- Laboratory of Fungal and Parasitic Molecular Biology, School of Medicine, University of Sfax, Sfax, Tunisia.
| | - Houaida Trabelsi
- Laboratory of Parasitology - Mycology, UH Habib Bourguiba, Sfax, Tunisia.,Laboratory of Fungal and Parasitic Molecular Biology, School of Medicine, University of Sfax, Sfax, Tunisia
| | - Salma Abbes
- Laboratory of Fungal and Parasitic Molecular Biology, School of Medicine, University of Sfax, Sfax, Tunisia
| | - Fatma Cheikhrouhou
- Laboratory of Parasitology - Mycology, UH Habib Bourguiba, Sfax, Tunisia.,Laboratory of Fungal and Parasitic Molecular Biology, School of Medicine, University of Sfax, Sfax, Tunisia
| | - Hayet Sellami
- Laboratory of Parasitology - Mycology, UH Habib Bourguiba, Sfax, Tunisia.,Laboratory of Fungal and Parasitic Molecular Biology, School of Medicine, University of Sfax, Sfax, Tunisia
| | - Fattouma Makni
- Laboratory of Parasitology - Mycology, UH Habib Bourguiba, Sfax, Tunisia.,Laboratory of Fungal and Parasitic Molecular Biology, School of Medicine, University of Sfax, Sfax, Tunisia
| | - Ali Ayadi
- Laboratory of Parasitology - Mycology, UH Habib Bourguiba, Sfax, Tunisia.,Laboratory of Fungal and Parasitic Molecular Biology, School of Medicine, University of Sfax, Sfax, Tunisia
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99938
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Gutiérrez-Venegas G, Torras-Ceballos A, Gómez-Mora JA, Fernández-Rojas B. Luteolin, quercetin, genistein and quercetagetin inhibit the effects of lipopolysaccharide obtained from Porphyromonas gingivalis in H9c2 cardiomyoblasts. Cell Mol Biol Lett 2017; 22:19. [PMID: 28878808 PMCID: PMC5583969 DOI: 10.1186/s11658-017-0047-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 08/21/2017] [Indexed: 12/26/2022] Open
Abstract
Background One of the microorganisms from dental plaque associated with severe inflammatory responses in infectious endocarditis is Porphyromonas gingivalis. It is a Gram-negative bacteria harvested from chronic periodontitis patients. Lipopolysaccharide (LPS) obtained from P. gingivalis promotes the expressions of interleukin-1 (IL-1), IL-6 and tumor necrosis factor alpha (TNF-α). Flavonoids are thought to participate in processes that control inflammation, such as the expression of cyclooxygenase-2 (COX-2). Methods We investigated the effects of luteolin, quercetin, genistein and quercetagetin on cardiomyoblasts treated with LPS alone or in combination with following inhibitors p38 (SB203580), ERK (PD98059), JNK (SP600125) and PKC (Calphostin C) for 1 h. The kinase activation and COX-2 expression levels were determined at the gene and protein levels. Results These flavonoids are considered to inhibit the activation of mitogen-activated protein kinase (MAPK) and the degradation of inhibitor of kappa B-alpha (IκB-α). They also play a role in COX-2 expression. Conclusion We conclude that the tested flavonoids inhibit inflammatory responses induced by LPS in H9c2 cells.
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Affiliation(s)
- Gloria Gutiérrez-Venegas
- Laboratorio de Bioquímica de la División de Estudios de Posgrado de la Facultad de Odontología, Universidad Nacional Autónoma de México Ciudad Universitaria, 04510 México DF, Mexico
| | - Alfredo Torras-Ceballos
- Laboratorio de Bioquímica de la División de Estudios de Posgrado de la Facultad de Odontología, Universidad Nacional Autónoma de México Ciudad Universitaria, 04510 México DF, Mexico
| | - Juan Arturo Gómez-Mora
- Laboratorio de Bioquímica de la División de Estudios de Posgrado de la Facultad de Odontología, Universidad Nacional Autónoma de México Ciudad Universitaria, 04510 México DF, Mexico
| | - Berenice Fernández-Rojas
- Laboratorio de Bioquímica de la División de Estudios de Posgrado de la Facultad de Odontología, Universidad Nacional Autónoma de México Ciudad Universitaria, 04510 México DF, Mexico
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99939
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Velmourougane K, Prasanna R. Influence of l-amino acids on aggregation and biofilm formation in Azotobacter chroococcum and Trichoderma viride. J Appl Microbiol 2017; 123:977-991. [PMID: 28731279 DOI: 10.1111/jam.13534] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 06/20/2017] [Accepted: 07/07/2017] [Indexed: 02/02/2023]
Abstract
AIM The effects of l-amino acids on growth and biofilm formation in Azotobacter chroococcum (Az) and Trichoderma viride (Tv) as single (Az, Tv) and staggered inoculated cultures (Az-Tv, Tv-Az) were investigated. METHODS AND RESULTS A preliminary study using a set of 20 l-amino acids, identified 6 amino acids (l-Glu, l-Gln, l-His, l-Ser, l-Thr and l-Trp) which significantly enhanced growth and biofilm formation. Supplementation of these amino acids at different concentrations revealed that 40 mmol l-1 was most effective. l-Glu and l-Gln favoured planktonic growth in both single and in staggered inoculated cultures, while l-Trp and l-Thr, enhanced aggregation and biofilm formation. Addition of l-Glu or l-Gln increased carbohydrate content and planktonic population. Principal component analysis revealed the significant role of proteins in growth and biofilm formation, particularly with supplementation of l-Trp, l-Thr and l-Ser. Azotobacter was found to function better as biofilm under staggered inoculated culture with Trichoderma. CONCLUSIONS The results illustrate that amino acids play crucial roles in microbial biofilm formation, by influencing growth, aggregation and carbohydrates synthesized. SIGNIFICANCE AND IMPACT OF THE STUDY The differential and specific roles of amino acids on biofilm formation are of significance for agriculturally important micro-organisms that grow as biofilms, colonize and benefit the plants more effectively.
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Affiliation(s)
- K Velmourougane
- Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - R Prasanna
- Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi, India
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99940
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99941
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Tongue Sole CD209: A Pattern-Recognition Receptor that Binds a Broad Range of Microbes and Promotes Phagocytosis. Int J Mol Sci 2017; 18:ijms18091848. [PMID: 28869534 PMCID: PMC5618497 DOI: 10.3390/ijms18091848] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 08/12/2017] [Accepted: 08/15/2017] [Indexed: 01/24/2023] Open
Abstract
CD209 is an immune receptor that plays an important role in the initiation of innate immunity and activation of adaptive immunity in mammals. However, much less is known about the immunological function of CD209 in lower vertebrates. In the present study, we examined the immune effect of a CD209 homologue (CsCD209) from the teleost fish tongue sole Cynoglossus semilaevis. CsCD209 possesses a lectin domain that shares high levels of similarity with the lectin domains of human and mouse CD209. CsCD209 expression was most abundant in kidney and blood and was significantly upregulated during bacterial infection. CsCD209 exhibited a subcellular localization mainly on the cell surface of myelomonocytes. Recombinant CsCD209 displayed apparent binding capacities to a broad range of bacteria and fungi, and significantly promoted the phagocytosis of the bound bacteria by C. semilaevis leukocytes. Collectively, the results indicate that teleost CD209 serves as a pattern recognition receptor that exerts an influence on the phagocytosis process during pathogen infections.
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99942
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Haeberlein S, Chevalley-Maurel S, Ozir-Fazalalikhan A, Koppejan H, Winkel BMF, Ramesar J, Khan SM, Sauerwein RW, Roestenberg M, Janse CJ, Smits HH, Franke-Fayard B. Protective immunity differs between routes of administration of attenuated malaria parasites independent of parasite liver load. Sci Rep 2017; 7:10372. [PMID: 28871201 PMCID: PMC5583236 DOI: 10.1038/s41598-017-10480-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 08/10/2017] [Indexed: 12/27/2022] Open
Abstract
In humans and murine models of malaria, intradermal immunization (ID-I) with genetically attenuated sporozoites that arrest in liver induces lower protective immunity than intravenous immunization (IV-I). It is unclear whether this difference is caused by fewer sporozoites migrating into the liver or by suboptimal hepatic and injection site-dependent immune responses. We therefore developed a Plasmodium yoelii immunization/boost/challenge model to examine parasite liver loads as well as hepatic and lymph node immune responses in protected and unprotected ID-I and IV-I animals. Despite introducing the same numbers of genetically attenuated parasites in the liver, ID-I resulted in lower sterile protection (53-68%) than IV-I (93-95%). Unprotected mice developed less sporozoite-specific CD8+ and CD4+ effector T-cell responses than protected mice. After immunization, ID-I mice showed more interleukin-10-producing B and T cells in livers and skin-draining lymph nodes, but fewer hepatic CD8 memory T cells and CD8+ dendritic cells compared to IV-I mice. Our results indicate that the lower protection efficacy obtained by intradermal sporozoite administration is not linked to low hepatic parasite numbers as presumed before, but correlates with a shift towards regulatory immune responses. Overcoming these immune suppressive responses is important not only for live-attenuated malaria vaccines but also for other live vaccines administered in the skin.
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Affiliation(s)
- Simone Haeberlein
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.,Institute of Parasitology, Justus-Liebig-University Giessen, Schubertstrasse 81, 35392, Giessen, Germany
| | - Séverine Chevalley-Maurel
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Arifa Ozir-Fazalalikhan
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Hester Koppejan
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Beatrice M F Winkel
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Jai Ramesar
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Shahid M Khan
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Robert W Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Geert-Grooteplein 28, 6525 GA, Nijmegen, The Netherlands
| | - Meta Roestenberg
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.,Department of Infectious Diseases, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Chris J Janse
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Hermelijn H Smits
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Blandine Franke-Fayard
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands.
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99943
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Thomson P, Medina DA, Garrido D. Human milk oligosaccharides and infant gut bifidobacteria: Molecular strategies for their utilization. Food Microbiol 2017; 75:37-46. [PMID: 30056961 DOI: 10.1016/j.fm.2017.09.001] [Citation(s) in RCA: 140] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 08/30/2017] [Accepted: 09/02/2017] [Indexed: 02/08/2023]
Abstract
Breast milk is the gold standard in infant nutrition. In addition to provide essential nutrients for the newborn, it contains multiple bioactive molecules that provide protection and stimulate proper development. Human milk oligosaccharides (HMO) are complex carbohydrates abundant in breast milk. Intriguingly, these molecules do not provide energy to the infant. Instead, these oligosaccharides are key to guide and support the assembly of a healthy gut microbiome in the infant, dominated by beneficial gut microbes such as Bifidobacterium. New analytical methods for glycan analysis, and next-generation sequencing of microbial communities, have been instrumental in advancing our understanding of the positive role of breast milk oligosaccharides on the gut microbiome, and the genomics and molecular strategies of Bifidobacterium to utilize these oligosaccharides. Moreover, novel approaches to simulate the impact of HMO on the gut microbiome have been described and successfully validated, including the incorporation of synthetic HMO and bovine milk oligosaccharides to infant formula. This review discusses recent advances regarding the influence of HMO in promoting a healthy gut microbiome, with emphasis in the molecular basis of the enrichment in beneficial Bifidobacterium, and novel approaches to replicate the effect of HMO using synthetic or bovine oligosaccharides.
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Affiliation(s)
- Pamela Thomson
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, Santiago, Chile
| | - Daniel A Medina
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, Santiago, Chile
| | - Daniel Garrido
- Department of Chemical and Bioprocess Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, Santiago, Chile.
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99944
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Zhao X, Dai Q, Jia R, Zhu D, Liu M, Wang M, Chen S, Sun K, Yang Q, Wu Y, Cheng A. Two Novel Salmonella Bivalent Vaccines Confer Dual Protection against Two Salmonella Serovars in Mice. Front Cell Infect Microbiol 2017; 7:391. [PMID: 28929089 PMCID: PMC5591321 DOI: 10.3389/fcimb.2017.00391] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Accepted: 08/22/2017] [Indexed: 12/12/2022] Open
Abstract
Non-typhoidal Salmonella includes thousands of serovars that are leading causes of foodborne diarrheal illness worldwide. In this study, we constructed three bivalent vaccines for preventing both Salmonella Typhimurium and Salmonella Newport infections by using the aspartate semialdehyde dehydrogenase (Asd)-based balanced-lethal vector-host system. The constructed Asd+ plasmid pCZ11 carrying a subset of the Salmonella Newport O-antigen gene cluster including the wzx-wbaR-wbaL-wbaQ-wzy-wbaW-wbaZ genes was introduced into three Salmonella Typhimurium mutants: SLT19 (Δasd) with a smooth LPS phenotype, SLT20 (Δasd ΔrfbN) with a rough LPS phenotype, and SLT22 (Δasd ΔrfbN ΔpagL::T araC PBADrfbN) with a smooth LPS phenotype when grown with arabinose. Immunoblotting demonstrated that SLT19 harboring pCZ11 [termed SLT19 (pCZ11)] co-expressed the homologous and heterologous O-antigens; SLT20 (pCZ11) exclusively expressed the heterologous O-antigen; and when arabinose was available, SLT22 (pCZ11) expressed both types of O-antigens, while in the absence of arabinose, SLT22 (pCZ11) expressed only the heterologous O-antigen. Exclusive expression of the heterologous O-antigen in Salmonella Typhimurium decreased the swimming ability of the bacterium and its susceptibility to polymyxin B. Next, the crp gene was deleted from the three recombinant strains for attenuation purposes, generating the three bivalent vaccine strains SLT25 (pCZ11), SLT26 (pCZ11), and SLT27 (pCZ11), respectively. Groups of BALB/c mice (12 mice/group) were orally immunized with 109 CFU of each vaccine strain twice at an interval of 4 weeks. Compared with a mock immunization, immunization with all three vaccine strains induced significant serum IgG responses against both Salmonella Typhimurium and Salmonella Newport LPS. The bacterial loads in the mouse tissues were significantly lower in the three vaccine-strain-immunized groups than in the mock group after either Salmonella Typhimurium or Salmonella Newport lethal challenge. All of the mice in the three vaccine-immunized groups survived the lethal Salmonella Typhimurium challenge. In contrast, SLT26 (pCZ11) and SLT27 (pCZ11) conferred full protection against lethal Salmonella Newport challenge, but SLT25 (pCZ11) provided only 50% heterologous protection. Thus, we developed two novel Salmonella bivalent vaccines, SLT26 (pCZ11) and SLT27 (pCZ11), suggesting that the delivery of a heterologous O-antigen in attenuated Salmonella strains is a prospective approach for developing Salmonella vaccines with broad serovar coverage.
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Affiliation(s)
- Xinxin Zhao
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan ProvinceChengdu, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Qinlong Dai
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Renyong Jia
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan ProvinceChengdu, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Dekang Zhu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan ProvinceChengdu, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Mafeng Liu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan ProvinceChengdu, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Mingshu Wang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan ProvinceChengdu, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Shun Chen
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan ProvinceChengdu, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Kunfeng Sun
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan ProvinceChengdu, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Qiao Yang
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan ProvinceChengdu, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Ying Wu
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan ProvinceChengdu, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
| | - Anchun Cheng
- Research Center of Avian Diseases, College of Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China.,Key Laboratory of Animal Disease and Human Health of Sichuan ProvinceChengdu, China.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural UniversityChengdu, China
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99945
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Harmer CJ, Hall RM. Targeted conservative formation of cointegrates between two DNA molecules containing IS26occurs via strand exchange at either IS end. Mol Microbiol 2017; 106:409-418. [DOI: 10.1111/mmi.13774] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2017] [Indexed: 11/26/2022]
Affiliation(s)
- Christopher J. Harmer
- School of Life and Environmental Sciences; The University of Sydney; Sydney New South Wales Australia
| | - Ruth M. Hall
- School of Life and Environmental Sciences; The University of Sydney; Sydney New South Wales Australia
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99946
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Interactome analysis of transcriptional coactivator multiprotein bridging factor 1 unveils a yeast AP-1-like transcription factor involved in oxidation tolerance of mycopathogen Beauveria bassiana. Curr Genet 2017; 64:275-284. [DOI: 10.1007/s00294-017-0741-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 08/21/2017] [Accepted: 08/22/2017] [Indexed: 01/18/2023]
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99947
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Phenotyping and susceptibility of established porcine cells lines to African Swine Fever Virus infection and viral production. Sci Rep 2017; 7:10369. [PMID: 28871180 PMCID: PMC5583235 DOI: 10.1038/s41598-017-09948-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 08/01/2017] [Indexed: 02/07/2023] Open
Abstract
African swine fever virus (ASFV) is a highly pathogenic, double-stranded DNA virus with a marked tropism for cells of the monocyte-macrophage lineage, affecting swine species and provoking severe economic losses and health threats. In the present study, four established porcine cell lines, IPAM-WT, IPAM-CD163, C∆2+ and WSL, were compared to porcine alveolar macrophage (PAM) in terms of surface marker phenotype, susceptibility to ASFV infection and virus production. The virulent ASFV Armenia/07, E70 or the naturally attenuated NHV/P68 strains were used as viral models. Cells expressed only low levels of specific receptors linked to the monocyte/macrophage lineage, with low levels of infection overall, with the exception of WSL, which showed more efficient production of strain NHV/P68 but not of strains E70 and Armenia/07.
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99948
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Jamrozy D, Coll F, Mather AE, Harris SR, Harrison EM, MacGowan A, Karas A, Elston T, Estée Török M, Parkhill J, Peacock SJ. Evolution of mobile genetic element composition in an epidemic methicillin-resistant Staphylococcus aureus: temporal changes correlated with frequent loss and gain events. BMC Genomics 2017; 18:684. [PMID: 28870171 PMCID: PMC5584012 DOI: 10.1186/s12864-017-4065-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 08/15/2017] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Horizontal transfer of mobile genetic elements (MGEs) that carry virulence and antimicrobial resistance genes mediates the evolution of methicillin-resistant Staphylococcus aureus, and the emergence of new MRSA clones. Most MRSA lineages show an association with specific MGEs and the evolution of MGE composition following clonal expansion has not been widely studied. RESULTS We investigated the genomes of 1193 S. aureus bloodstream isolates, 1169 of which were MRSA, collected in the UK and the Republic of Ireland between 2001 and 2010. The majority of isolates belonged to clonal complex (CC)22 (n = 923), which contained diverse MGEs including elements that were found in other MRSA lineages. Several MGEs showed variable distribution across the CC22 phylogeny, including two antimicrobial resistance plasmids (pWBG751-like and SAP078A-like, carrying erythromycin and heavy metal resistance genes, respectively), a pathogenicity island carrying the enterotoxin C gene and two phage types Sa1int and Sa6int. Multiple gains and losses of these five MGEs were identified in the CC22 phylogeny using ancestral state reconstruction. Analysis of the temporal distribution of the five MGEs between 2001 and 2010 revealed an unexpected reduction in prevalence of the two plasmids and the pathogenicity island, and an increase in the two phage types. This occurred across the lineage and was not correlated with changes in the relative prevalence of CC22, or of any sub-lineages within in. CONCLUSIONS Ancestral state reconstruction coupled with temporal trend analysis demonstrated that epidemic MRSA CC22 has an evolving MGE composition, and indicates that this important MRSA lineage has continued to adapt to changing selective pressure since its emergence.
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Affiliation(s)
- Dorota Jamrozy
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA UK
| | - Francesc Coll
- London School of Hygiene and Tropical Medicine, London, WC1E 7HT UK
| | - Alison E. Mather
- Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES UK
| | - Simon R. Harris
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA UK
| | - Ewan M. Harrison
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge, CB2 0QQ UK
| | - Alasdair MacGowan
- British Society for Antimicrobial Chemotherapy, B1 3NJ, Birmingham, UK
| | - Andreas Karas
- Public Health England, Clinical Microbiology and Public Health Laboratory, Cambridge, CB21 5XA UK
| | - Tony Elston
- Colchester Hospital University NHS Foundation Trust, Colchester, CO4 5JL UK
| | - M. Estée Török
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge, CB2 0QQ UK
- Public Health England, Clinical Microbiology and Public Health Laboratory, Cambridge, CB21 5XA UK
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, CB2 0QQ UK
| | - Julian Parkhill
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA UK
| | - Sharon J. Peacock
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA UK
- London School of Hygiene and Tropical Medicine, London, WC1E 7HT UK
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, Cambridge, CB2 0QQ UK
- Cambridge University Hospitals NHS Foundation Trust, Cambridge, CB2 0QQ UK
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99949
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Liu W, Li M, Yan J, Yan Y. The role of Hfq in regulation of lipA expression in Pseudomonas protegens Pf-5. Sci Rep 2017; 7:10356. [PMID: 28871123 PMCID: PMC5583355 DOI: 10.1038/s41598-017-10808-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 08/15/2017] [Indexed: 11/09/2022] Open
Abstract
Pseudomonas lipase is a well-studied lipase. However, few studies have been conducted to examine the mechanisms underlying the regulation of the lipase expression. Hfq is a global regulatory protein that, among others, controls the expression of multiple genes, regulate bacterial peristalsis, and participates in the regulation of quorum-sensing (QS) system. In this study, the effects of Hfq on lipase expression were investigated by knocking out the hfq and rsmY genes or overexpressing of hfq and rsmY genes. We found that Hfq regulates the expression of lipA at both transcriptional and translational levels. The translational level was the main regulatory level of lipA. Hfq also regulates the expression and stability of rsmY. Additionally, using hfq/rsmY double gene knock-out, we showed that Hfq can directly bind to the rsmY to regulate lipA activity. In conclusion, our results indicate that Hfq regulates the expression of rsmY mainly at the translational level to influence the expression of lipA in Pseudomonas protegens Pf-5.
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Affiliation(s)
- Wu Liu
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Menggang Li
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Jinyong Yan
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Yunjun Yan
- Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.
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99950
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Tjagur S, Mändar R, Punab M. Prevalence of Mycoplasma genitalium and other sexually transmitted infections causing urethritis among high-risk heterosexual male patients in Estonia. Infect Dis (Lond) 2017; 50:133-139. [PMID: 28868962 DOI: 10.1080/23744235.2017.1366044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
BACKGROUND We aimed to evaluate the prevalence of sexually transmitted infections (STI, including Mycoplasma genitalium, Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis) among high-risk heterosexual male patients and to clarify their potency to cause complaints and inflammation. METHODS The study group included 825 men (18.0-49.5 y) consulting andrologist at Tartu University Hospital (Estonia) due to subjectively perceived risk of STI. Patients completed STI risk behaviour questionnaire. First voided urine was analysed for white blood cells and STIs. RESULTS In total 193 (23.4%) patients were positive for one or multiple STI. The prevalence of C. trachomatis, M. genitalium, N. gonorrhoeae, T. vaginalis and combined STI was 14.3%, 4.4%, 2.7%, 0.7% and 1.3%, respectively. N. gonorrhoeae had the highest potency to generate inflammatory reaction in first voided urine (100%) followed by C. trachomatis (72.0%), M. genitalium (63.9%) and T. vaginalis (33.3%). N. gonorrhoeae and T. vaginalis caused the highest mean number of complaints while half of T. vaginalis cases and nearly fifth of M. genitalium and C. trachomatis cases were asymptomatic. CONCLUSIONS C. trachomatis has the highest prevalence among Estonian high-risk men but M. genitalium holds an important second place. Prevalence of combined STIs is low. N. gonorrhoeae has the highest potency to generate urethral inflammation followed by C. trachomatis and M. genitalium. The highest number of complaints is also associated with N. gonorrhoeae while half of T. vaginalis cases and nearly a fifth of M. genitalium and C. trachomatis cases are asymptomatic.
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Affiliation(s)
- Stanislav Tjagur
- a Tartu University Hospital, Centre of Andrology , Tartu , Estonia.,b Faculty of Medicine , University of Tartu , Tartu , Estonia
| | - Reet Mändar
- c Department of Microbiology, Faculty of Medicine , University of Tartu, Institute of Biomedicine and Translational Medicine , Tartu , Estonia.,d Competence Centre on Health Technologies , Tartu , Estonia
| | - Margus Punab
- a Tartu University Hospital, Centre of Andrology , Tartu , Estonia.,e Department of Surgery, Faculty of Medicine , University of Tartu, Institute of Clinical Medicine , Tartu , Estonia
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