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Search Results: 1 - 10 of 325468 matches for " Yogesh S Shouche "
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A Variant Quorum Sensing System in Aeromonas veronii MTCC 3249
Kamlesh Jangid,Perunninakulath S. Parameswaran,Yogesh S. Shouche
Sensors , 2012, DOI: 10.3390/s120403814
Abstract: We have investigated the quorum sensing control in Aeromonas veronii MTCC 3249, originally isolated as A. culicicola from the midgut of Culex quinquefasciatus. Based on biosensor assays, the bacterium showed constant production of multiple acyl-homoserine lactones (AHLs) with increasing cell-density. The luxRI gene homologs, acuR (A. culicicola transcriptional Regulator) and acuI (A. culicicola autoInducer) were successfully amplified by inverse-PCR. Sequence analysis indicated acuRI were divergent from all known quorum sensing gene homologs in Aeromonas. Two localized regions in the C-terminal autoinducer binding domain of acuR showed indels suggesting variations in autoinducer specificity. Further, only a single copy of the quorum sensing genes was detected, suggesting a tight regulation of mechanisms under its control. Chromatography and further chemical analysis identified two AHLs in the culture supernatant: 6-carboxy-HHL (homoadipyl homoserine lactone), a novel AHL, and N-tetradecanoylhomoserine lactone. The existence of a potentially variant quorum sensing system might therefore, reflect in some way the ecological strategies adopted by this bacterium in the mosquito midgut.
luxRI homologs are universally present in the genus Aeromonas
Kamlesh Jangid, Richard Kong, Milind S Patole, Yogesh S Shouche
BMC Microbiology , 2007, DOI: 10.1186/1471-2180-7-93
Abstract: Of all the 73 Aeromonas strains used in the study, seventy-one strains elicited acyl-homoserine lactone-mediated response in multiple biosensor strains. However, dot blot hybridization revealed that the luxRI homologs are present in all the strains. PCR amplification and sequencing revealed that the luxRI homologs shared a very high percentage sequence similarity. No evidence for lateral gene transfer of the luxRI homologs between aeromonads and other genera was noted.We propose that the luxRI quorum sensing gene homologs are universally present in the genus Aeromonas independently from their origin. This study is the first genus-wide report of the taxonomic distribution of the luxRI homologs.The genus Aeromonas is a medically important genus in the family Aeromonadaceae within the γ-Proteobacteria [1]. Aeromonas species, referred to as "emerging pathogens" [2], are suspected to cause multiple infections in humans [3,4]. In addition, they cause diseases in amphibians, reptiles and fish [5]. They are more frequently isolated from samples of medical importance than from environmental sources [6,7]. Their multifactorial virulence determinants include surface associated factors like adhesins, extracellular proteins like siderophores for iron acquisition, and exoenzymes and exotoxins like α-haemolysin and serine proteases amongst others. The expression of many of these virulence determinants is associated with high cell densities [8-11] and are therefore putatively under control by quorum sensing.Quorum sensing is a density-dependent regulation of the gene expression by self-generated signal molecules, such as the acyl-homoserine lactones (AHLs) in gram-negative bacteria. In A. hydrophila, the serine- and metalloprotease activities [12,13], biofilm development [14], and butanediol fermentation [15] are under quorum sensing control. Although, the AHL mediated production of extracellular proteases in A. hydrophila is decreased in the presence of long chain AHLs [12], mutat
Detection of Conjugation Related Type Four Secretion Machinery in Aeromonas culicicola
Ashraf Yusuf Rangrez, Kannayakanahalli Maheshwarappa Dayananda, Santosh Atanur, Rajendra Joshi, Milind S. Patole, Yogesh S. Shouche
PLOS ONE , 2006, DOI: 10.1371/journal.pone.0000115
Abstract: Background Aeromonas sp. can now be considered relatively common enteropathogens due to the increase of diseases in humans. Aeromonas culicicola is a gram negative rod-shaped bacterium isolated for the first time from the mosquito mid-gut, but subsequently detected in other insects and waters also. Our previous study discovered that A. culicicola harbors three plasmids, which we designated as pAc3249A, pAc3249B and pAc3249C. We investigated and report here the existence and genetic organization of a Conjugal Type IV Secretion System (TFSS) in pAc3249A. Methodology/Principle Finding The complete operon is 11,061 bp in length and has G+C content of 47.20% code for 12 ORFs. The gene order and orientation were similar to those found in other bacteria with some differences. We have designated this system as AcTra for Aeromonas culicicola transfer system. BLAST results of ORFs and phylogenetic analysis showed significant similarity towards the respective proteins of the IncI2 plasmid R721 of E. coli. Other bioinformatics studies have been performed to predict conserved motifs/domains, signal peptides, transmembrane helices, etc. of the ORFs. Conclusions/Significance BLAST results of ORFs and phylogenetic analysis showed significant similarity towards the respective proteins of the IncI2 plasmid R721 of E. coli.
Purification and characterization of an extreme halothermophilic protease from a halophilic bacterium Chromohalobacter sp. TVSP101
Vidyasagar, Malashetty;Prakash, S.;Mahajan, Vineet;Shouche, Yogesh S.;Sreeramulu, K.;
Brazilian Journal of Microbiology , 2009, DOI: 10.1590/S1517-83822009000100002
Abstract: an extreme halophilic bacterium was isolated from solar saltern samples and identified based on biochemical tests and 16s r rna sequencing as chromohalobacter sp. strain tvsp101. the halophilic protease was purified using ultrafiltration, ethanol precipitation, hydrophobic interaction column chromatography and gel permeation chromatography to 180 fold with 22% yield. the molecular mass of the protease determined by sds page was 66 kda. the purified enzyme was salt dependent for its activity and stability with an optimum of 4.5 m nacl. the optimum temperature for maximum protease activity was 75°c. the protease was optimally active at ph 8 and retained more than 80% of its activity in the range of ph 7-10. sucrose and glycine at 10% (w/v) were the most effective osmolytes, retained 100% activity in the absence of nacl. the activity was completely inhibited by zncl2 (2 mm), 0.1% sds and pmsf (1mm). the enzyme was not inhibited by 1mm of pepstatin, edta and pcmb. the protease was active and retained 100% it activity in 10% (v/v) dmso, dmf, ethanol and acetone.
Comparative Genome Analysis of Megasphaera sp. Reveals Niche Specialization and Its Potential Role in the Human Gut
Sudarshan Anand Shetty, Nachiket Prakash Marathe, Vikram Lanjekar, Dilip Ranade, Yogesh S. Shouche
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0079353
Abstract: With increasing number of novel bacteria being isolated from the human gut ecosystem, there is a greater need to study their role in the gut ecosystem and their effect on the host health. In the present study, we carried out in silico genome-wide analysis of two novel Megasphaera sp. isolates NM10 (DSM25563) and BL7 (DSM25562), isolated from feces of two healthy individuals and validated the key features by in vitro studies. The analysis revealed the general metabolic potential, adaptive features and the potential effects of these isolates on the host. The comparative genome analysis of the two human gut isolates NM10 and BL7 with ruminal isolate Megasphaera elsdenii (DSM20460) highlighted the differential adaptive features for their survival in human gut. The key findings include features like bile resistance, presence of various sensory and regulatory systems, stress response systems, membrane transporters and resistance to antibiotics. Comparison of the “glycobiome” based on the genomes of the ruminal isolate with the human gut isolates NM10 and BL revealed the presence of diverse and unique sets of Carbohydrate-Active enzymes (CAZymes) amongst these isolates, with a higher collection of CAZymes in the human gut isolates. This could be attributed to the difference in host diet and thereby the environment, consequently suggesting host specific adaptation in these isolates. In silico analysis of metabolic potential predicted the ability of these isolates to produce important metabolites like short chain fatty acids (butyrate, acetate, formate, and caproate), vitamins and essential amino acids, which was further validated by in vitro experiments. The ability of these isolates to produce important metabolites advocates for a potential healthy influence on the host. Further in vivo studies including transcriptomic and proteomic analysis will be required for better understanding the role and impact of these Megasphaera sp. isolates NM10 and BL7 on the human host.
Genus-Wide Physicochemical Evidence of Extracellular Crystalline Silver Nanoparticles Biosynthesis by Morganella spp
Rasesh Y. Parikh, Rajesh Ramanathan, Peter J. Coloe, Suresh K. Bhargava, Milind S. Patole, Yogesh S. Shouche, Vipul Bansal
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0021401
Abstract: This study was performed to determine whether extracellular silver nanoparticles (AgNPs) production is a genus-wide phenotype associated with all the members of genus Morganella, or only Morganella morganii RP-42 isolate is able to synthesize extracellular Ag nanoparticles. To undertake this study, all the available Morganella isolates were exposed to Ag+ ions, and the obtained nanoproducts were thoroughly analyzed using physico-chemical characterization tools such as transmission electron microscopy (TEM), UV-visible spectrophotometry (UV-vis), and X-ray diffraction (XRD) analysis. It was identified that extracellular biosynthesis of crystalline silver nanoparticles is a unique biochemical character of all the members of genus Morganella, which was found independent of environmental changes. Significantly, the inability of other closely related members of the family Enterobacteriaceae towards AgNPs synthesis strongly suggests that AgNPs synthesis in the presence of Ag+ ions is a phenotypic character that is uniquely associated with genus Morganella.
Lactobacillus plantarum (VR1) isolated from an Ayurvedic medicine (Kutajarista) ameliorates in vitro cellular damage caused by Aeromonas veronii
Himanshu Kumar, Ashraf Y Rangrez, Kannayakanahalli M Dayananda, Ashwini N Atre, Milind S Patole, Yogesh S Shouche
BMC Microbiology , 2011, DOI: 10.1186/1471-2180-11-152
Abstract: We report the isolation of L. plantarum (VR1) from Kutajarista, and efficacy of its cell free supernatant (CFS) in amelioration of cytotoxicity caused by Aeromonas veronii. On the part of probiotic attributes, VR1 was tolerant to pH 2, 0.3% bile salts and simulated gastric juice. Additionally, VR1 also exhibited adhesive property to human intestinal HT-29 cell line. Furthermore, CFS of VR1 was antibacterial to enteric pathogens like Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Aeromonas veronii and clinical isolates of P. aeruginosa and E. coli. Detailed study regarding the effect of VR1 CFS on A. veronii cytotoxicity showed a significant decrease in vacuole formation and detrimental cellular changes in Vero cells. On the other hand, A. veronii CFS caused disruption of tight junction proteins ZO-1 and actin in MDCK cell line, which was prevented by pre-incubation with CFS of VR1.This is the first study to report isolation of L. plantarum (VR1) from Kutajarista and characterisation for its probiotic attributes. Our study demonstrates the antagonistic property of VR1 to A. veronii and effect of VR1 CFS in reduction of cellular damage caused by A. veronii in both Vero and MDCK cell lines.Lactic acid bacteria is now widely used as probiont for its multifactorial benefits to humans as well as to organisms like fish, poultry and other live stock. In addition to various sources of isolation [1-3], several recent studies have described the isolation and characterisation of probiotic microorganisms from traditionally fermented sources like Dongchimi, Kimchi, Meju, and Doenjang [4], and Kallappam batter, Koozh and Mor Kuzhambu [5]. Likewise, traditional Ayurvedic medicines might serve as a source and a reservoir of potential probiotic microbes. Nevertheless, there are very little efforts made in exploration of probionts from ayurvedic fermented sources. To the best of our knowledge, Kanjika is the only Ayurvedic source explored in detail for the isolation
Characterization of Leptospira borgpetersenii isolates from field rats (Rattus norvegicus) by 16S rRNA and lipL32 gene sequencing
Vedhagiri, Kumaresan;Natarajaseenivasan, Kalimuthusamy;Prabhakaran, Shanmugarajan G.;Selvin, Joseph;Narayanan, Ramasamy;Shouche, Yogesh S.;Vijayachari, Paluru;Ratnam, Sivalingam;
Brazilian Journal of Microbiology , 2010, DOI: 10.1590/S1517-83822010000100022
Abstract: the main goal of this study was to evaluate the prevalence of leptospirosis among field rodents of tiruchirappalli district, tamil nadu, india. in total 35 field rats were trapped and tested for seroprevalence by the microscopic agglutination test (mat). isolation of leptospires was performed from blood and kidney tissues and characterized to serovar level. genomospecies identification was carried out using 16s rrna and lipl32 gene sequencing. the molecular phylogeny was constructed to find out species segregation. seroprevalence was about 51.4 %, and the predominant serovars were autumnalis, javanica, icterohaemorrhagiae and pomona. two isolates from the kidneys were identified as serovar javanica of serogroup javanica, and sequence based molecular phylogeny indicated these two isolates were leptospira borgpetersenii.
Comparison of 16S rRNA gene sequences of genus Methanobrevibacter
Abhijit S Dighe, Kamlesh Jangid, José M González, Vyankatesh J Pidiyar, Milind S Patole, Dilip R Ranade, Yogesh S Shouche
BMC Microbiology , 2004, DOI: 10.1186/1471-2180-4-20
Abstract: The phylogenetic analysis of the genus based on 786 bp aligned region from fifty-four representative sequences of the 120 available sequences for the genus revealed seven multi-member groups namely, Ruminantium, Smithii, Woesei, Curvatus, Arboriphilicus, Filiformis, and the Termite gut symbionts along with three separate lineages represented by Mbr. wolinii, Mbr. acididurans, and termite gut flagellate symbiont LHD12. The cophenetic correlation coefficient, a test for the ultrametric properties of the 16S rRNA gene sequences used for the tree was found to be 0.913 indicating the high degree of goodness of fit of the tree topology. A significant relationship was found between the 16S rRNA sequence similarity (S) and the extent of DNA hybridization (D) for the genus with the correlation coefficient (r) for logD and logS, and for [ln(-lnD) and ln(-lnS)] being 0.73 and 0.796 respectively. Our analysis revealed that for this genus, when S = 0.984, D would be <70% at least 99% of the times, and with 70% D as the species "cutoff", any 16S rRNA gene sequence showing <98% sequence similarity can be considered as a separate species. In addition, we deduced group specific signature positions that have remained conserved in evolution of the genus.A very significant relationship between D and S was found to exist for the genus Methanobrevibacter, implying that it is possible to predict D from S with a known precision for the genus. We propose to include the termite gut flagellate symbiont LHD12, the methanogenic endosymbionts of the ciliate Nyctotherus ovalis, and rat feces isolate RT reported earlier, as separate species of the genus Methanobrevibacter.Methanogens are members of the domain Archaea, and fall within the kingdom Euryarchaeota [1]. They are obligate anaerobes and can be unambiguously differentiated from other organisms since they all produce methane as a major catabolic product [2]. A significant source of global atmospheric methane (≤ 1.30 μmol g [fresh weight]-1
Analysis of Mitochondrial DNA Sequences in Childhood Encephalomyopathies Reveals New Disease-Associated Variants
Aijaz A. Wani, Sajad H. Ahanger, Sharmila A. Bapat, Ashraf Y. Rangrez, Nitin Hingankar, C. G. Suresh, Shama Barnabas, Milind S. Patole, Yogesh S. Shouche
PLOS ONE , 2007, DOI: 10.1371/journal.pone.0000942
Abstract: Background Mitochondrial encephalomyopathies are a heterogeneous group of clinical disorders generally caused due to mutations in either mitochondrial DNA (mtDNA) or nuclear genes encoding oxidative phosphorylation (OXPHOS). We analyzed the mtDNA sequences from a group of 23 pediatric patients with clinical and morphological features of mitochondrial encephalopathies and tried to establish a relationship of identified variants with the disease. Methodology/Principle Findings Complete mitochondrial genomes were amplified by PCR and sequenced by automated DNA sequencing. Sequencing data was analyzed by SeqScape software and also confirmed by BLASTn program. Nucleotide sequences were compared with the revised Cambridge reference sequence (CRS) and sequences present in mitochondrial databases. The data obtained shows that a number of known and novel mtDNA variants were associated with the disease. Most of the non-synonymous variants were heteroplasmic (A4136G, A9194G and T11916A) suggesting their possibility of being pathogenic in nature. Some of the missense variants although homoplasmic were showing changes in highly conserved amino acids (T3394C, T3866C, and G9804A) and were previously identified with diseased conditions. Similarly, two other variants found in tRNA genes (G5783A and C8309T) could alter the secondary structure of Cys-tRNA and Lys-tRNA. Most of the variants occurred in single cases; however, a few occurred in more than one case (e.g. G5783A and A10149T). Conclusions and Significance The mtDNA variants identified in this study could be the possible cause of mitochondrial encephalomyopathies with childhood onset in the patient group. Our study further strengthens the pathogenic score of known variants previously reported as provisionally pathogenic in mitochondrial diseases. The novel variants found in the present study can be potential candidates for further investigations to establish the relationship between their incidence and role in expressing the disease phenotype. This study will be useful in genetic diagnosis and counseling of mitochondrial diseases in India as well as worldwide.
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