Displaying publications 1 - 20 of 485 in total

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  1. mazE Antitoxin of Toxin Antitoxin System and fbpA as Reliable Targets to Eradication of Neisseria meningitidis
    Maleki A, Ghafourian S, Pakzad I, Badakhsh B, Sadeghifard N
    Curr Pharm Des, 2018;24(11):1204-1210.
    PMID: 29237374 DOI: 10.2174/1381612824666171213094730
    BACKGROUND: Neisseria meningitidis is considered as a dangerous pathogen threatening human health. Nowadays, the new drug target is focused. Toxin antitoxin (TA) system is recently identified as an antimicrobial drug target. Also, in N. meningitidis, iron-uptake system could be an interesting target for drug discovery.

    METHODS: In this study, fbpA and mazE genes were chosen as new antimicrobial targets and treated with antisense peptide nucleic acid (PNA). Firstly, they were evaluated by bioinformatics and then analyzed by experimental procedures. Secondly, the functionality was evaluated by stress conditions.

    RESULTS: Our results interestingly demonstrated that when fbpA and mazE loci of N. meningitidis were targeted by antisense PNA, 8 µM concentration of fbpA-PNA as well as 30 µM concentration of mazE-PNA inhibited the growth of N. meningitides and were found to be bacteriostatic, whereas 10 μM concentration of fbpA-PNA showed bacteriocidal activity.

    CONCLUSION: Our findings demonstrated the bactriocidal activity of fbpA-PNA and bacteriostatic activity of mazEPNA. Therefore, mazE and fbpA genes should be potent antimicrobial targets but further analysis including in vivo analysis should be performed.

    Matched MeSH terms: Bacterial Proteins/drug effects*; Bacterial Proteins/genetics
  2. cagA gene variants in Malaysian Helicobacter pylori strains isolated from patients of different ethnic groups
    Ramelah M, Aminuddin A, Alfizah H, Isa MR, Jasmi AY, Tan HJ, et al.
    FEMS Immunol. Med. Microbiol., 2005 May 1;44(2):239-42.
    PMID: 15866222
    Helicobacter pylori infection of a distinct subtype of cagA may lead to different pathological manifestation. The aim of this study is to determine the presence of cagA gene and its variants in H. pylori infection among different ethnic groups and its effect on gastroduodenal diseases. Overall detection of cagA among the 205 clinical isolates of H. pylori was 94%. Variations in size of the 3' region of cagA gene were examined among 192 Malaysian H. pylori cagA-positive strains. Results showed that three cagA variants differing in fragment length of PCR products were detected and designated as type A (621-651bp), type B (732-735bp) and type C (525 bp). Although there was no association between any of the cagA subtypes with peptic ulcer disease (p>0.05), an association between cagA subtypes with a specific ethnic group was observed. Specific-cagA subtype A strains were predominantly isolated from Chinese compared to Malays and Indians (p<0.0005), and cagA subtype B strains were predominantly isolated from Malays and Indians compared to Chinese (p<0.05). The cagA type A strains of H. pylori is commonly found in the Chinese patients who have a higher risk of peptic ulcer disease, thus indicating that it could be used as an important clinical biomarker for a more severe infection.
    Matched MeSH terms: Bacterial Proteins/genetics*
  3. Fulltext Whole genome sequencing and analysis reveal insights into the genetic structure, diversity and evolutionary relatedness of luxI and luxR homologs in bacteria belonging to the Sphingomonadaceae family
    Gan HM, Gan HY, Ahmad NH, Aziz NA, Hudson AO, Savka MA
    Front Cell Infect Microbiol, 2014;4:188.
    PMID: 25621282 DOI: 10.3389/fcimb.2014.00188
    Here we report the draft genomes and annotation of four N-acyl homoserine lactone (AHL)-producing members from the family Sphingomonadaceae. Comparative genomic analyses of 62 Sphingomonadaceae genomes were performed to gain insights into the distribution of the canonical luxI/R-type quorum sensing (QS) network within this family. Forty genomes contained at least one luxR homolog while the genome of Sphingobium yanoikuyae B1 contained seven Open Reading Frames (ORFs) that have significant homology to that of luxR. Thirty-three genomes contained at least one luxI homolog while the genomes of Sphingobium sp. SYK6, Sphingobium japonicum, and Sphingobium lactosutens contained four luxI. Using phylogenetic analysis, the sphingomonad LuxR homologs formed five distinct clades with two minor clades located near the plant associated bacteria (PAB) LuxR solo clade. This work for the first time shows that 13 Sphingobium and one Sphingomonas genome(s) contain three convergently oriented genes composed of two tandem luxR genes proximal to one luxI (luxR-luxR-luxI). Interestingly, luxI solos were identified in two Sphingobium species and may represent species that contribute to AHL-based QS system by contributing AHL molecules but are unable to perceive AHLs as signals. This work provides the most comprehensive description of the luxI/R circuitry and genome-based taxonomical description of the available sphingomonad genomes to date indicating that the presence of luxR solos and luxI solos are not an uncommon feature in members of the Sphingomonadaceae family.
    Matched MeSH terms: Bacterial Proteins/genetics*; Bacterial Proteins/metabolism; Bacterial Proteins/chemistry
  4. Virulotyping of Salmonella enterica subsp. enterica isolated from indigenous vegetables and poultry meat in Malaysia using multiplex-PCR
    Khoo CH, Cheah YK, Lee LH, Sim JH, Salleh NA, Sidik SM, et al.
    Antonie Van Leeuwenhoek, 2009 Nov;96(4):441-57.
    PMID: 19565351 DOI: 10.1007/s10482-009-9358-z
    The increased occurrence of Salmonella occurrence in local indigenous vegetables and poultry meat can be a potential health hazards. This study is aimed to detect the prevalence of twenty different virulence factors among Salmonella enterica strains isolated from poultry and local indigenous vegetables in Malaysia via an optimized, rapid and specific multiplex PCR assay. The assay encompasses a total of 19 Salmonella pathogenicity islands genes and a quorum sensing gene (sdiA) in three multiplex reaction sets. A total of 114 Salmonella enterica isolates belonging to 38 different serovars were tested. Each isolate in under this study was found to possess up to 70% of the virulence genes tested and exhibited variable pathogenicity gene patterns. Reproducibility of the multiplex PCR assay was found to be 100% and the detection limit of the optimized multiplex PCR was tested with lowest detectable concentration of DNA 0.8 pg microl(-1). This study demonstrated various Salmonella pathogenicity island virulence gene patterns even within the same serovar. This sets of multiplex PCR system provide a fast and reliable typing approach based on Salmonella pathogenicity islands, thus enabling an effective monitoring of emerging pathogenic Salmonella strains as an additional tool in Salmonella surveillance studies.
    Matched MeSH terms: Bacterial Proteins/genetics*
  5. Virulence, Host-Selective Toxin Production, and Development of Three Cochliobolus Phytopathogens Lacking the Sfp-Type 4'-Phosphopantetheinyl Transferase Ppt1
    Zainudin NA, Condon B, De Bruyne L, Van Poucke C, Bi Q, Li W, et al.
    Mol Plant Microbe Interact, 2015 Oct;28(10):1130-41.
    PMID: 26168137 DOI: 10.1094/MPMI-03-15-0068-R
    The Sfp-type 4'-phosphopantetheinyl transferase Ppt1 is required for activation of nonribosomal peptide synthetases, including α-aminoadipate reductase (AAR) for lysine biosynthesis and polyketide synthases, enzymes that biosynthesize peptide and polyketide secondary metabolites, respectively. Deletion of the PPT1 gene, from the maize pathogen Cochliobolus heterostrophus and the rice pathogen Cochliobolus miyabeanus, yielded strains that were significantly reduced in virulence to their hosts. In addition, ppt1 mutants of C. heterostrophus race T and Cochliobolus victoriae were unable to biosynthesize the host-selective toxins (HST) T-toxin and victorin, respectively, as judged by bioassays. Interestingly, ppt1 mutants of C. miyabeanus were shown to produce tenfold higher levels of the sesterterpene-type non-HST ophiobolin A, as compared with the wild-type strain. The ppt1 strains of all species were also reduced in tolerance to oxidative stress and iron depletion; both phenotypes are associated with inability to produce extracellular siderophores biosynthesized by the nonribosomal peptide synthetase Nps6. Colony surfaces were hydrophilic, a trait previously associated with absence of C. heterostrophus Nps4. Mutants were decreased in asexual sporulation and C. heterostrophus strains were female-sterile in sexual crosses; the latter phenotype was observed previously with mutants lacking Nps2, which produces an intracellular siderophore. As expected, mutants were albino, since they cannot produce the polyketide melanin and were auxotrophic for lysine because they lack an AAR.
    Matched MeSH terms: Bacterial Proteins/genetics; Bacterial Proteins/metabolism
  6. Vibrio coralliirubri sp. nov., a new species isolated from mucus of red coral (Corallium rubrum) collected at Procida island, Italy
    Poli A, Romano I, Mastascusa V, Buono L, Orlando P, Nicolaus B, et al.
    Antonie Van Leeuwenhoek, 2018 Jul;111(7):1105-1115.
    PMID: 29299771 DOI: 10.1007/s10482-017-1013-5
    Strain Corallo1T was isolated from mucus of red coral (Corallium rubrum) at Punta Pizzaco (Procida island, Naples, Italy). It was characterised as a Gram-stain negative, motile, rod-shaped bacterium. Strain Corallo1T was found to show positive responses for cytochrome-c oxidase, catalase, reduction of nitrate and nitrite, β-galactosidase activity and hydrolysis of starch, xylan, peptone, Tween 40, Tween 80 and casein. Strain Corallo1T was found to be mesophilic, neutrophilic to alkalophilic and slightly halophilic. According to analysis of the almost-complete 16S rRNA gene, strain Corallo1T is closely related to Vibrio celticus (100% sequence similarity), Vibrio gigantis (100%), Vibrio crassostreae (99.7%), Vibrio artabrorum (99.7%) and Vibrio pomeroyi (99.6%). MLSA of five housekeeping genes (atpA, pyrH, recA, rpoA and rpoD) was performed to refine the phylogenetic relationships of strain Corallo1T. A draft genome sequence of strain Corallo1T was obtained. The DNA G+C content of this strain was determined to be 44.5 mol %. The major cellular fatty acids of strain Corallo1T are C16:1, n-C16:0 and C18:1, and the major isoprenoid ubiquinone is Q8. ANI indexes, in silico estimations of DDH values and wet lab DDH values demonstrated that strain Corallo1T represents an independent genomospecies. Based on a polyphasic taxonomic characterisation, strain Corallo1T is concluded to represent a novel species of the genus Vibrio, for which the name Vibrio coralliirubri sp. nov. is proposed. The type strain is Corallo1T (= DSM 27495T = CIP 110630T).
    Matched MeSH terms: Bacterial Proteins/genetics
  7. Fulltext Variations in ceftazidime and amoxicillin-clavulanate susceptibilities within a clonal infection of Burkholderia pseudomallei
    Sam IC, See KH, Puthucheary SD
    J Clin Microbiol, 2009 May;47(5):1556-8.
    PMID: 19297597 DOI: 10.1128/JCM.01657-08
    A patient with a clonal infection of Burkholderia pseudomallei had subpopulations with ceftazidime and amoxicillin-clavulanate susceptibilities that differed among the clinical specimens. Resistance was associated with a novel Cys69Tyr substitution in the Ambler class A beta-lactamase. Susceptibility testing of multiple colony variants from different sites should be performed for patients with culture-confirmed melioidosis.
    Matched MeSH terms: Bacterial Proteins/genetics
  8. Fulltext Variant of Helicobacter pylori CagA proteins induce different magnitude of morphological changes in gastric epithelial cells
    Alfizah H, Ramelah M
    Malays J Pathol, 2012 Jun;34(1):29-34.
    PMID: 22870595 MyJurnal
    Infection with Helicobacter pylori cagA-positive strains is associated with gastroduodenal diseases. The CagA protein is injected into gastric epithelial cells and supposedly induces morphological changes termed the 'hummingbird phenotype', which is associated with scattering and increased cell motility. The molecular mechanisms leading to the CagA-dependent morphological changes are only partially known. The present study was carried out to investigate the effect of CagA variants on the magnitude of gastric epithelial cell morphological changes. Recombinant 3' terminal domains of cagA were cloned and expressed in a gastric epithelial cell line and the hummingbird phenotype was quantified by microscopy. The 3' region of the cagA gene of Malaysian H. pylori isolates showed six sub-genotypes that differed in the structural organization of the EPIYA repeat sequences. The percentage of hummingbird cells induced by CagA increased with duration of transfection. The hummingbird phenotype was observed to be more pronounced when CagA with 4 EPIYA motifs rather than 3 or 2 EPIYA motifs was produced. The activity of different CagA variants in the induction of the hummingbird phenotype in gastric epithelial cells depends at least in part on EPIYA motif variability. The difference in CagA genotypes might influence the potential of individual CagAs to cause morphological changes in host cells. Depending on the relative exposure of cells to CagA genotypes, this may contribute to the various disease outcomes caused by H. pylori infection in different individuals.
    Matched MeSH terms: Bacterial Proteins/genetics*; Bacterial Proteins/metabolism; Bacterial Proteins/chemistry
  9. Fulltext Variable characteristics of bacteriocin-producing Streptococcus salivarius strains isolated from Malaysian subjects
    Barbour A, Philip K
    PLoS One, 2014;9(6):e100541.
    PMID: 24941127 DOI: 10.1371/journal.pone.0100541
    Salivaricins are bacteriocins produced by Streptococcus salivarius, some strains of which can have significant probiotic effects. S. salivarius strains were isolated from Malaysian subjects showing variable antimicrobial activity, metabolic profile, antibiotic susceptibility and lantibiotic production.
    Matched MeSH terms: Bacterial Proteins/biosynthesis; Bacterial Proteins/isolation & purification
  10. VapC toxin switches M. smegmatis cells into dormancy through 23S rRNA cleavage
    Zamakhaev M, Grigorov A, Bespyatykh J, Azhikina T, Goncharenko A, Shumkov M
    Arch Microbiol, 2022 Dec 15;205(1):28.
    PMID: 36520276 DOI: 10.1007/s00203-022-03363-1
    Mycobacterium tuberculosis is an extremely successful pathogen known for its ability to cause latent infection. The latter is connected with the bacterium resting state development and is considered to be based on the activity of toxin-antitoxin (TA) systems at least in part. Here we studied the physiological and proteomic consequences of VapC toxin overexpression together with the features of the protein synthesis apparatus and compared them with the characteristics of dormant mycobacterial cells in an M. smegmatis model. The findings allow suggesting the mechanism mycobacteria enter dormancy, which is realized through VapC-caused cleavage of the 23S rRNA Sarcin-Ricin loop followed by conservation of stalled ribosomes in a membrane-associated manner. The found features of resting mycobacteria protein synthesis apparatus hypothesize the mechanisms of resuscitation from dormancy through the ribosomes de-association off the membrane accompanied by the 23S rRNA break curing, and could be of value for the development of principally new antituberculosis agents.
    Matched MeSH terms: Bacterial Proteins/genetics; Bacterial Proteins/metabolism
  11. Fulltext Vancomycin-resistant Enterococcus faecium of multi locus sequence type 18 in Malaysia
    Poh LW, Rukman AW, Cheah YK, Norital Z, Nazri AM, Mariana NS
    Med J Malaysia, 2012 Dec;67(6):639-40.
    PMID: 23770967 MyJurnal
    Vancomycin-resistant Enterococcus faecium (VREF) in human infections mostly belong to the high-risk, epidemic, clonal complex-17 (CC17) group. Treatment limitation and high conjugation frequency makes it dominant in hospitals worldwide. We investigated positive cultures by Pulse-field gel electrophoresis (PFGE), multi locus sequence typing (MLST). DNA of two strains (A2 and C) appeared to be clonally related by PFGE. Three strains were of ST 18 type (A1, B and C) and strain A2 is of a new ST 596. This ST 18 type strain found in our study is crucial and is believed to be the first in Malaysia.
    Matched MeSH terms: Bacterial Proteins
  12. Validation of a Burkholderia pseudomallei hypothetical protein and determination of its translational start codon using chromosomal integration of His-Tag coding sequence
    Yam H, Abdul Rahim A, Gim Luan O, Samian R, Abdul Manaf U, Mohamad S, et al.
    Protein J, 2012 Mar;31(3):246-9.
    PMID: 22354666 DOI: 10.1007/s10930-012-9398-5
    In this post genomic era, there are a great number of in silico annotated hypothetical genes. However, experimental validation of the functionality of these genes remains tentative. Two of the major challenges faced by researcher are whether these hypothetical genes are protein-coding genes and whether their corresponding predicted translational start codons are correct. In this report, we demonstrate a convenient procedure to validate the presence of a hypothetical gene product of BPSS1356 from Burkholderia pseudomallei as well as its start codon. It was done by integration of a His-Tag coding sequence into C-terminal end of BPSS1356 gene via homologous recombination. We then purified the native protein using affinity chromatography. The genuine start codon of BPSS1356 was then determined by protein N-terminal sequencing.
    Matched MeSH terms: Bacterial Proteins/genetics; Bacterial Proteins/isolation & purification; Bacterial Proteins/metabolism*
  13. Unscrambling the effect of C-terminal tail deletion on the stability of a cold-adapted, organic solvent stable lipase from Staphylococcus epidermidis AT2
    Kamarudin NH, Rahman RN, Ali MS, Leow TC, Basri M, Salleh AB
    Mol Biotechnol, 2014 Aug;56(8):747-57.
    PMID: 24771007 DOI: 10.1007/s12033-014-9753-1
    Terminal moieties of most proteins are long known to be disordered and flexible. To unravel the functional role of these regions on the structural stability and biochemical properties of AT2 lipase, four C-terminal end residues, (Ile-Thr-Arg-Lys) which formed a flexible, short tail-like random-coil segment were targeted for mutation. Swapping of the tail-like region had resulted in an improved crystallizability and anti-aggregation property along with a slight shift of the thermostability profile. The lipolytic activity of mutant (M386) retained by 43 % compared to its wild-type with 18 % of the remaining activity at 45 °C. In silico analysis conducted at 25 and 45 °C was found to be in accordance to the experimental findings in which the RMSD values of M386 were more stable throughout the total trajectory in comparison to its wild-type. Terminal moieties were also observed to exhibit large movement and flexibility as denoted by high RMSF values at both dynamics. Variation in organic solvent stability property was detected in M386 where the lipolytic activity was stimulated in the presence of 25 % (v/v) of DMSO, isopropanol, and diethyl ether. This may be worth due to changes in the surface charge residues at the mutation point which probably involve in protein-solvent interaction.
    Matched MeSH terms: Bacterial Proteins/genetics*; Bacterial Proteins/metabolism*; Bacterial Proteins/chemistry
  14. Unravelling protein -organic solvent interaction of organic solvent tolerant elastase from Pseudomonas aeruginosa strain K crystal structure
    Said ZSAM, Arifi FAM, Salleh AB, Rahman RNZRA, Leow ATC, Latip W, et al.
    Int J Biol Macromol, 2019 Apr 15;127:575-584.
    PMID: 30658145 DOI: 10.1016/j.ijbiomac.2019.01.056
    The utilization of organic solvents as reaction media for enzymatic reactions provides numerous industrially attractive advantages. However, an adaptation of enzyme towards organic solvent is unpredictable and not fully understood because of limited information on the organic solvent tolerant enzymes. To understand how the enzyme can adapt to the organic solvent environment, structural and computational approaches were employed. A recombinant elastase from Pseudomonas aeruginosa strain K was an organic solvent tolerant zinc metalloprotease was successfully crystallized and diffracted up to 1.39 Å. Crystal structure of elastase from strain K showed the typical, canonical alpha-beta hydrolase fold consisting of 10-helices (118 residues), 10- β-strands (38 residues) and 142 residues were formed other secondary structure such as loop and coil to whole structure. The elastase from Pseusomonas aeruginosa strain K possess His-140, His-144 and Glu-164 served as a ligand for zinc ion. The conserved catalytic triad was composed of Glu-141, Tyr-155 and His-223. Three-dimensional structure features such as calcium-binding and presence of disulphide-bridge contribute to the stabilizing the elastase structure. Molecular dynamic (MD) simulation of elastase revealed that, amino acid residues located at the surface area and disulphide bridge in Cys-30 to Cys-58 were responsible for enzyme stability in organic solvents.
    Matched MeSH terms: Bacterial Proteins/chemistry*
  15. Fulltext Understanding the dimorphic lifestyles of human gastric pathogen Helicobacter pylori using the SWATH-based proteomics approach
    Loke MF, Ng CG, Vilashni Y, Lim J, Ho B
    Sci Rep, 2016 05 25;6:26784.
    PMID: 27222005 DOI: 10.1038/srep26784
    Helicobacter pylori may reside in the human stomach as two morphological forms: the culturable spiral form and the viable but non-culturable (VBNC) coccoid form. This bacterium transforms from spiral to coccoid under in vitro suboptimal conditions. However, both spiral and coccoid have demonstrated its infectivity in laboratory animals, suggesting that coccoid may potentially be involved in the transmission of H. pylori. To determine the relevance of the coccoid form in viability and infectivity, we compared the protein profiles of H. pylori coccoids obtained from prolonged (3-month-old) culture with that of 3-day-old spirals of two H. pylori standard strains using SWATH (Sequential Window Acquisition of all Theoretical mass spectra)-based approach. The protein profiles reveal that the coccoids retained basal level of metabolic proteins and also high level of proteins that participate in DNA replication, cell division and biosynthesis demonstrating that coccoids are viable. Most interestingly, these data also indicate that the H. pylori coccoids possess higher level of proteins that are involved in virulence and carcinogenesis than their spiral counterparts. Taken together, these findings have important implications in the understanding on the pathogenesis of H. pylori-induced gastroduodenal diseases, as well as the probable transmission mode of this bacterium.
    Matched MeSH terms: Bacterial Proteins/analysis*; Bacterial Proteins/biosynthesis; Bacterial Proteins/genetics
  16. Fulltext Type II bacterial toxin-antitoxins: hypotheses, facts, and the newfound plethora of the PezAT system
    Chan WT, Garcillán-Barcia MP, Yeo CC, Espinosa M
    FEMS Microbiol Rev, 2023 Sep 05;47(5).
    PMID: 37715317 DOI: 10.1093/femsre/fuad052
    Toxin-antitoxin (TA) systems are entities found in the prokaryotic genomes, with eight reported types. Type II, the best characterized, is comprised of two genes organized as an operon. Whereas toxins impair growth, the cognate antitoxin neutralizes its activity. TAs appeared to be involved in plasmid maintenance, persistence, virulence, and defence against bacteriophages. Most Type II toxins target the bacterial translational machinery. They seem to be antecessors of Higher Eukaryotes and Prokaryotes Nucleotide-binding (HEPN) RNases, minimal nucleotidyltransferase domains, or CRISPR-Cas systems. A total of four TAs encoded by Streptococcus pneumoniae, RelBE, YefMYoeB, Phd-Doc, and HicAB, belong to HEPN-RNases. The fifth is represented by PezAT/Epsilon-Zeta. PezT/Zeta toxins phosphorylate the peptidoglycan precursors, thereby blocking cell wall synthesis. We explore the body of knowledge (facts) and hypotheses procured for Type II TAs and analyse the data accumulated on the PezAT family. Bioinformatics analyses showed that homologues of PezT/Zeta toxin are abundantly distributed among 14 bacterial phyla mostly in Proteobacteria (48%), Firmicutes (27%), and Actinobacteria (18%), showing the widespread distribution of this TA. The pezAT locus was found to be mainly chromosomally encoded whereas its homologue, the tripartite omega-epsilon-zeta locus, was found mostly on plasmids. We found several orphan pezT/zeta toxins, unaccompanied by a cognate antitoxin.
    Matched MeSH terms: Bacterial Proteins/genetics; Bacterial Proteins/metabolism
  17. Fulltext Twitching motility of Stenotrophomonas maltophilia under iron limitation: In-silico, phenotypic and proteomic approaches
    V K, Neela VK
    Virulence, 2020 Dec;11(1):104-112.
    PMID: 31957553 DOI: 10.1080/21505594.2020.1713649
    This study investigates the twitching ability of 28 clinical and five environmental strains of S. maltophilia grown under iron-depleted condition through in-silico, phenotypic and proteomics approaches. Rapid Annotations using Subsystem Technology (RAST) analysis revealed the presence of 21 targets of type IV pilus shared across S. maltophilia strains K279a, R551-3, D457 and JV3. The macroscopic twitching assay showed that only clinical isolates produced a zone of twitching with a mean of 22.00 mm under normal and 25.00 mm under iron-depleted conditions. (p = 0.002). Environmental isolates did not show any significant twitching activity in both conditions tested. Isobaric Tags for Relative and Absolute Quantification (ITRAQ) analysis showed altered expression of twitching motility protein PilT (99.08-fold change), flagellar biosynthesis protein FliC (20.14-fold change), and fimbrial protein (0.70-fold change) in response to iron-depleted condition. Most of the strains that have the ability to twitch under the normal condition, exhibit enhanced twitching during iron limitation.
    Matched MeSH terms: Bacterial Proteins/metabolism
  18. Tuberculosis vaccine candidates based on mycobacterial cell envelope components
    Sarmiento ME, Alvarez N, Chin KL, Bigi F, Tirado Y, García MA, et al.
    Tuberculosis (Edinb), 2019 03;115:26-41.
    PMID: 30948174 DOI: 10.1016/j.tube.2019.01.003
    Even after decades searching for a new and more effective vaccine against tuberculosis, the scientific community is still pursuing this goal due to the complexity of its causative agent, Mycobacterium tuberculosis (Mtb). Mtb is a microorganism with a robust variety of survival mechanisms that allow it to remain in the host for years. The structure and nature of the Mtb envelope play a leading role in its resistance and survival. Mtb has a perfect machinery that allows it to modulate the immune response in its favor and to adapt to the host's environmental conditions in order to remain alive until the moment to reactivate its normal growing state. Mtb cell envelope protein, carbohydrate and lipid components have been the subject of interest for developing new vaccines because most of them are responsible for the pathogenicity and virulence of the bacteria. Many indirect evidences, mainly derived from the use of monoclonal antibodies, support the potential protective role of Mtb envelope components. Subunit and DNA vaccines, lipid extracts, liposomes and membrane vesicle formulations are some examples of technologies used, with encouraging results, to evaluate the potential of these antigens in the protective response against Mtb.
    Matched MeSH terms: Bacterial Proteins/metabolism
  19. Transformation of cyclodextrin glucanotransferase (CGTase) from aqueous suspension to fine solid particles via electrospraying
    Saallah S, Naim MN, Mokhtar MN, Abu Bakar NF, Gen M, Lenggoro IW
    Enzyme Microb Technol, 2014 Oct;64-65:52-9.
    PMID: 25152417 DOI: 10.1016/j.enzmictec.2014.06.002
    In this study, the potential of electrohydrodynamic atomization or electrospraying to produce nanometer-order CGTase particles from aqueous suspension was demonstrated. CGTase enzyme was prepared in acetate buffer solution (1% v/v), followed by electrospraying in stable Taylor cone-jet mode. The deposits were collected on aluminium foil (collector) at variable distances from the tip of spraying needle, ranging from 10 to 25 cm. The Coulomb fission that occurs during electrospraying process successfully transformed the enzyme to the solid state without any functional group deterioration. The functional group verification was conducted by FTIR analysis. Comparison between the deposit and the as-received enzyme in dry state indicates almost identical spectra. By increasing the distance of the collector from the needle tip, the average particle size of the solidified enzyme was reduced from 200±117 nm to 75±34 nm. The average particle sizes produced from the droplet fission were in agreement with the scaling law models. Enzyme activity analysis showed that the enzyme retained its initial activity after the electrospraying process. The enzyme particles collected at the longest distance (25 cm) demonstrated the highest enzyme activity, which indicates that the activity was controlled by the enzyme particle size.
    Matched MeSH terms: Bacterial Proteins/metabolism; Bacterial Proteins/chemistry*
  20. Transcriptional analysis of nitrogen fixation in Paenibacillus durus during growth in nitrogen-enriched medium
    Halim MA, Choo QC, Ghazali AHA, Wajidi MFF, Najimudin N
    Lett Appl Microbiol, 2021 May;72(5):610-618.
    PMID: 33525052 DOI: 10.1111/lam.13455
    Paenibacillus durus strain ATCC 35681T is a Gram-positive diazotroph that displayed capability of fixing nitrogen even in the presence of nitrate or ammonium. However, the nitrogen fixation activity was detected only at day 1 of growth when cultured in liquid nitrogen-enriched medium. The transcripts of all the nifH homologues were present throughout the 9-day study. When grown in nitrogen-depleted medium, nitrogenase activities occurred from day 1 until day 6 and the nifH transcripts were also present during the course of the study albeit at different levels. In both studies, the absence of nitrogen fixation activity regardless of the presence of the nifH transcripts raised the possibility of a post-transcriptional or post-translational regulation of the system. A putative SigA box sequence was found upstream of the transcription start site of nifB1, the first gene in the major nitrogen fixation cluster. The upstream region of nifB2 showed a promoter recognizable by SigE, a sigma factor normally involved in sporulation.
    Matched MeSH terms: Bacterial Proteins/genetics
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