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We describe here the identification of sodC gene from enteroaggregative Escherichia coli (EAggEC). A 294 bp gene‐specific fragment was amplified from the organism by DNA as well as RT‐PCR using primers from bacterial sodC sequences. The... more
We describe here the identification of sodC gene from enteroaggregative Escherichia coli (EAggEC). A 294 bp gene‐specific fragment was amplified from the organism by DNA as well as RT‐PCR using primers from bacterial sodC sequences. The metal co‐factor present in the protein was confirmed by running samples in native gels and inhibiting with 2 mM potassium cyanide. However, the nonpathogenic E. coli possesses the gene but does not express it. Thus, the presence of copper‐zinc superoxide dismutase encoded by sodC was demonstrated for the first time in EAggEC, which means it could be a novel candidate for a virulence marker.
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Rheumatic heart is an autoimmune sequel of pharyngitis and rheumatic fever that leads to permanent heart valves damage, especially the mitral valves. The mitral valves, which are responsible for the binding of auto-antibodies during... more
Rheumatic heart is an autoimmune sequel of pharyngitis and rheumatic fever that leads to permanent heart valves damage, especially the mitral valves. The mitral valves, which are responsible for the binding of auto-antibodies during immune response generation, leads to valves scarring and eventually mitral valve dysfunction. Recently, exosomes (EXOs), the nano-sized-vesicles, which ranges in size from 30-150 nm, are involved in various cardiovascular physiological and pathological processes. These vesicles are found in several body fluids such as plasma, serum and also in cell culture media. Exosomal cargo contains proteins, which are taken up by the recipient cells and modulates the cellular characteristics. The role of exosomal proteins in RHD is still obscure. Hence, the present study is designed to unveil the role of exosomal proteins in increasing disease severity during RHD. In this study, the exosomes were isolated from biological fluids (plasma and pericardial fluid) of RHD ...
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Research Interests: Microbiology, Parasitology, Medical Microbiology, Biology, Medicine, and 15 moreIndia, Developing Country, Animals, DNA profiling, Polymerase Chain Reaction, DNA fingerprinting, Genetic Polymorphism, Entamoeba histolytica, Genetic variation, Large Scale, Genetic Variability, Epidemiologic Studies, Entamoeba, DNA polymorphism, and Random amplified polymorphic DNA
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Research Interests: Microbiology, Biofilms, Biology, Medicine, India, and 15 moreBiological Sciences, Virulence, Humans, Sequence alignment, Escherichia coli, Phenotype, Protein Sequence Analysis, Genotype, Amino Acid Sequence, Bacterial Adhesion, Hemagglutination, Fimbria, Molecular Sequence Data, Child preschool, and Medical and Health Sciences
A galactose-specific adhesin was isolated from the fimbriae of an enteroaggregative Escherichia coli (EAEC) strain. The adhesin was found to be a high molecular weight aggregate of the 18-kDa monomer. The dimeric (36 kDa) and tetrameric... more
A galactose-specific adhesin was isolated from the fimbriae of an enteroaggregative Escherichia coli (EAEC) strain. The adhesin was found to be a high molecular weight aggregate of the 18-kDa monomer. The dimeric (36 kDa) and tetrameric (76 kDa) forms appeared in sodium dodecyl sulphate polyacrylamide gel electrophoresis when a higher concentration of the adhesin was used. The IgGAD (IgG against adhesin) obtained from the immune sera raised in rabbits against purified adhesin could detect all three forms of the adhesin even from the crude fimbrial preparation. The IgGAD failed to recognize the adhesin in the presence of galactose, thereby suggesting the antibody-binding site and the sugar-binding site on the adhesin might be same or overlapping. Furthermore, the IgGAD could localize the adhesin exclusively on the fimbriae as observed in immunogold electron microscopy. The aggregative adherence of the bacteria to HEp-2 cells was reduced to 70% in the presence of the IgGAD. A glycoprotein (34 kDa) present in the membrane fraction of HEp-2 cells interacted with the purified adhesin in a galactose-specific manner. The IgGAD could recognize the adhesin from the crude fimbrial preparation of 9 out of 10 clinical isolates of EAEC strains but failed to identify any protein from the crude fimbrial preparation of Salmonella typhimurium (fim +ve as well as fim -ve strain), Vibrio cholerae (WO7) or Escherichia coli DH5alpha.
Research Interests: Microbiology, Electron Microscopy, Medical Microbiology, Biology, Membrane Proteins, and 15 moreMedicine, Cell line, Humans, Escherichia coli, Animals, Epithelial cells, Current, Molecular weight, Polyacrylamide Gel Electrophoresis, Protein Binding, Binding Site, Fimbria, immunoglobulin G, Immunoblotting, and High Molecular Weight
Rheumatic heart disease (RHD), an autoimmune disease sequel of rheumatic fever, which leads to dysfunction of the heart, is a major public health problem in developing countries that contributes to significant cardiac morbidity and... more
Rheumatic heart disease (RHD), an autoimmune disease sequel of rheumatic fever, which leads to dysfunction of the heart, is a major public health problem in developing countries that contributes to significant cardiac morbidity and mortality. High mortality was observed in low-income and middle-income countries and even in some groups living in high-income countries. Hence, elucidation of the pathogenic mechanisms in RHD, for therapeutic applications is of major concern and need of the hour. Although, molecular mimicry (MM) is the most established theory for RHD development, however contribution of other factors cannot be ignored. Studies have indicated the role of host-pathogen interacting proteins and immunological factors (T cells-cytokines and chemokines) in RHD, however not much information is available regarding role of polymorphic genes during RHD. The present review, specifically highlights the association of genetic polymorphism with disease manifestation.
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The emergence of multi drug resistance in non-small cell lung cancer (NSCLC) patients is a major challenge towards the efficacy of chemotherapy. Thus, there is an urgent need for the newer, better clinically targeted strategies to treat... more
The emergence of multi drug resistance in non-small cell lung cancer (NSCLC) patients is a major challenge towards the efficacy of chemotherapy. Thus, there is an urgent need for the newer, better clinically targeted strategies to treat this disease. Earlier studies from our laboratory revealed the apoptotic activity of Maackia amurensis agglutinin (MAA) in human NSCLC cells. In this study, the effect of MAA on drug resistant NSCLC cells was investigated. Two Paclitaxel-resistant NSCLC sub-lines (A549/PTX100 and NCI-H460/PTX100) were developed from A549 & NCI-H460 cell lines respectively. The generation of drug resistance phenotype was confirmed by the expression of cell surface MDR-1. Both the drug resistant sub-lines showed distinct morphological alterations. MAA interacted with the cell-surface protein(s) of apparent Mr ~66 kDa and induced apoptosis in both the sub-lines through intrinsic/mitochondrial pathway, involving reduction in mitochondrial trans-membrane potential, up-regulation of Bax, unaltered/decreased expression of Bcl-XL, release of mitochondrial cytochrome c into the cytosol and activation of pro-caspases (−9&-3). Our findings highlighted the potential of this plant agglutinin to serve as an apoptosis inducing agent in drug resistant NSCLC cells.
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Research Interests:
Type 2 diabetes mellitus (T2DM) is a major risk factor associated with hepatocellular carcinoma (HCC). However, the association of T2DM with liver cirrhosis and therapy response in HCC patients is not clear. Hence, in this study, we have... more
Type 2 diabetes mellitus (T2DM) is a major risk factor associated with hepatocellular carcinoma (HCC). However, the association of T2DM with liver cirrhosis and therapy response in HCC patients is not clear. Hence, in this study, we have evaluated the influence of T2DM on liver cirrhosis severity of HCC and sorafenib response. HCC patients were divided in two groups: T2DM (n = 20) and non-T2DM (nT2DM; n = 50). We found significantly higher number of patients in T2DM group had decompensated liver disease with Child-Turcotte-Pugh score ≥ 7. Additionally, 71.4% patients were observed to be sorafenib sensitive in T2DM group which was significantly higher as compared to 30% in nT2DM group. This study has highlighted the predisposition of HCC patients with T2DM toward more severe liver disease who were found to be better respondents of sorafenib. Impact statement We have explored the association of type 2 diabetes mellitus (T2DM) on liver cirrhosis severity along with response toward sora...
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Uveitis is a cause for concern in the developing countries like India. Its poor diagnosis and lack of proper therapeutics often cause blindness in children and young adults. Moreover, the exact mechanism of pathogenesis of different types... more
Uveitis is a cause for concern in the developing countries like India. Its poor diagnosis and lack of proper therapeutics often cause blindness in children and young adults. Moreover, the exact mechanism of pathogenesis of different types of uveitis is still elusive. Modern proteomic techniques are found to be advantageous for an in-depth understanding of the ocular physiology using proteomic diversity. Our aim was to identify unique proteins involved in the pathogenesis of autoimmune or noninfectious uveitis. Vitreous fluid samples (n = 90) were obtained from infectious (N = 34) and noninfectious (N = 56) uveitis patients, and their protein profiles were compared by analysing sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and 2D electrophoresis. Unique proteins were identified through matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and further studied for pathway analysis. Protein spots having different molecular we...
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MicroRNA-122 (miR-122) is liver specific and plays an important role in physiology as well as diseases including hepatocellular carcinoma (HCC). Downregulation of miR-122 in HCC modulates apoptosis. Similarly, the putative targets of... more
MicroRNA-122 (miR-122) is liver specific and plays an important role in physiology as well as diseases including hepatocellular carcinoma (HCC). Downregulation of miR-122 in HCC modulates apoptosis. Similarly, the putative targets of miR-122, the forkhead box (FOX) family genes also play an important role in the regulation of apoptosis. Hence, an interplay between miR-122 and FOX family genes has been explored in this study. Initially, an augmentation of apoptosis was noticed in HepG2 cells after transfection with miR-122. Further, the predicted miR-122 targets, the FOX family genes (FOXM1b, FOXP1, and FOXO4) were selected via in silico analysis based on their role in apoptosis. We checked the expression of all these genes at transcript level after the transfection of miR-122 and found that the relative expression of FOXP1 and FOXM1b was significantly downregulated (p < 0.005) and that of FOXO4 was upregulated (p < 0.005). Thus, the finding indicates deregulation of these FOX ...
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Group A streptococcus (GAS), Streptococcus pyogenes manifests plethora of diseases through its explicit virulence factors. Among these, the recently deciphered MSCRAMMs, Streptococcal collagen-like (Scls) adhesins are most studied... more
Group A streptococcus (GAS), Streptococcus pyogenes manifests plethora of diseases through its explicit virulence factors. Among these, the recently deciphered MSCRAMMs, Streptococcal collagen-like (Scls) adhesins are most studied proteins in context of their biophysically stable collagenous-sequence (Gly-X-Y) despite the difference from analogous mammalian-collagen. Based on recent evidence on collagen-mimetic Scls, we elucidated biomaterial-potential of the unmodified, recombinant Scl1 (rScl1). Initially, rScl1 trimeric- assembly yielded its stability in silico than the monomeric-unit. Thereby, rScl1 matrix characterization was confirmed in vitro. rScl1 exhibited high A549 and HepG2 cell- viability—rScl1 dose incremented to 20.0 µg/ml at time points up to 24 hr, and on 24 hr stored-dishes—deliberating it non-cytotoxic. Imploring cell-adhesion potential, we observed increased cell-counts tangential to rScl1-gradient. This affirmative prelude on rScl1 as a supporting-matrix cued its...
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Giardia lamblia (syn. G. intestinalis) infection in young adults leads to acute/chronic diarrhea in some individuals and is asymptomatic in others. Recently, G. lamblia strains have been characterized as group A (symptomatic) and group B... more
Giardia lamblia (syn. G. intestinalis) infection in young adults leads to acute/chronic diarrhea in some individuals and is asymptomatic in others. Recently, G. lamblia strains have been characterized as group A (symptomatic) and group B (asymptomatic or control) by advanced isoenzyme and molecular biology studies. In the present brief pilot study, ten G. lamblia isolates obtained from five symptomatic (group A) and five asymptomatic (group B) persons were characterized by isoenzyme and random amplified polymorphic DNA (RAPD) analysis. Isoenzyme analysis demonstrated remarkable homogeneity in seven enzyme patterns, the exception, being that of phosphoglucomutase, for which two zymodemes (I and III) were observed. In contrast, RAPD analysis showed homogeneity for eight primers; exceptions were two primers, A02 and B05, which separated group A G. lamblia isolates into two rapdemes (A(R1) and A(R2)) and group B G. lamblia isolates into four rapdemes (B(R1), B(R2), B(R3) and B(R4)). Further phenetic analysis showed average genetic distances of 0.105 within group A and 0.121 within group B G. lamblia isolates according to Jaccord&#39;s distance scale, which suggests that both lineages appear to consist of a range of variants with no significant (P &lt; 0.05) genetic diversity. The two techniques demonstrated a positive association with regard to differentiation between group A and group B G. lamblia isolates. These very preliminary results indicate that RAPD analysis could be a potentially useful substitute for isoenzyme analysis.
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Hepatocellular carcinoma (HCC) is the primary liver malignancy that contributes towards the second most common cause of cancer-related mortality. The targeted chemotherapeutic agent, sorafenib, is known to show a statistically significant... more
Hepatocellular carcinoma (HCC) is the primary liver malignancy that contributes towards the second most common cause of cancer-related mortality. The targeted chemotherapeutic agent, sorafenib, is known to show a statistically significant but limited overall survival advantage in advanced HCC. However, the individual patient response towards sorafenib varies drastically, with most experiencing stable disease and few with partial response; complete response is very rare. Progressive disease despite the treatment is also evident in many patients, indicating drug resistance. These varied responses have been linked with the modulation of several intracellular signaling pathways. Notably, the regulation of these pathways through diverse operating biomolecules, including microRNAs (miRNAs), is the focus of recent studies. MicroRNAs are tiny, non-coding RNA molecules that regulate the expression of several target genes. In addition, miRNAs are known to play a role in the progression of HCC...
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Research Interests: Microbiology, Medical Microbiology, Biology, Adolescent, Medicine, and 15 moreIndia, Biological Sciences, Cerebrospinal Fluid, Humans, Child, Infant, Adult, Bronchitis, Bacteremia, Genetic variation, Haemophilus Infections Market, Haemophilus influenzae, Child preschool, Carrier state, and Medical and Health Sciences
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Background. There is evidence that Tregs are important to prevent allergic diseases like asthma but limited literature exists on role of TH17 cells in allergic diseases. Methods. Fifty children with asthma and respiratory allergy (study... more
Background. There is evidence that Tregs are important to prevent allergic diseases like asthma but limited literature exists on role of TH17 cells in allergic diseases. Methods. Fifty children with asthma and respiratory allergy (study group) and twenty healthy children (control group) were recruited in this study. Total IgE levels and pulmonary function tests were assessed. The expression of Tregs and cytokines was determined by flow cytometry. Results. The average level of total IgE in study group (316.8 ± 189.8 IU/mL) was significantly higher than controls (50 ± 17.5 IU/mL, P < 0.0001). The frequency of TH17 cells and culture supernatant level of IL-17 in study group (12.09 ± 8.67 pg/mL) was significantly higher than control group (2.01 ± 1.27 pg/mL, P < 0.001). Alternatively, the frequency of FOXP3 level was significantly lower in study group [(49.00 ± 13.47)%] than in control group [(95.91 ± 2.63)%] and CD4(+)CD25(+)FOXP3(+) to CD4(+)CD25(+) ratio was also significantly ...
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Background. Rheumatic fever (RF)/rheumatic heart disease (RHD) continue to be a neglected public health priority. We carried out a registry-based control project, prospective surveillance and sample surveys to estimate the burden of... more
Background. Rheumatic fever (RF)/rheumatic heart disease (RHD) continue to be a neglected public health priority. We carried out a registry-based control project, prospective surveillance and sample surveys to estimate the burden of disease. Methods. We trained healthcare providers and established a surveillance system for the 1.1 million population of Rupnagar district in Punjab. In sample surveys conducted among schools, physicians examined the sampled children. Children with a cardiac murmur were investigated by echocardiography. Throat swabs were obtained from a sub-sample, and group A streptococci (GAS) were identified and emm typed by standard laboratory methods. We estimated the morbidity rates for RF/RHD from surveillance data and school surveys using a correction factor to account for under-registration of cases in the registry. Results. A total of 813 RF/RHD cases were registered from 2002 to 2009. Of the 203 RF and 610 RHD cases, respectively, 51.2% and 36.7% were males. ...
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Group A streptococcus (GAS) causes a wide variety of life threatening diseases in developing countries like India. Characterization of GAS is therefore necessary for prevention and control of the disease. Genotypic analysis of GAS is... more
Group A streptococcus (GAS) causes a wide variety of life threatening diseases in developing countries like India. Characterization of GAS is therefore necessary for prevention and control of the disease. Genotypic analysis of GAS is largely lacking from India, therefore an attempt was made to study the genotype distribution of north Indian GAS isolates. Sixty clinical isolates of GAS, (52 collected from pharyngitis and 8 from RF/RHD patients) were genotyped by various molecular techniques like restriction enzyme analysis (REA), ribotyping, PCR-ribotyping and random amplification of polymorphic DNA (RAPD). A few isolates were also typed by emm gene sequencing for comparison. REA using Hind III digestion differentiated the isolates into six different patterns. The same isolates were grouped into three ribotypes when analyzed for PCR - ribotyping of 16S- 23S rRNA region. However, RAPD fingerprints generated higher level of discrimination by AP4 and AP5 primers showing 12 rapdemes, fol...
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In vitro and in vivo studies have suggested that reduced astrocytic uptake of neuronally released glutamate, alterations in expression of glial fibrillary acidic protein (GFAP) and aquaporin-4 (AQP-4) contribute to brain edema in acute... more
In vitro and in vivo studies have suggested that reduced astrocytic uptake of neuronally released glutamate, alterations in expression of glial fibrillary acidic protein (GFAP) and aquaporin-4 (AQP-4) contribute to brain edema in acute liver failure (ALF). However, there is no evidence to date to suggest that these alterations occur in patients with ALF. We analyzed the mRNA expression of excitatory amino acid transporters (EAAT-1, EAAT-2), GFAP, and AQP-4 in the cerebral cortex obtained at autopsy from eight patients with ALF and from seven patients with no evidence of hepatic or neurological disorders by real-time PCR, and protein expression was assessed using immunoblotting and immunohistochemistry. We demonstrated a significant decrease in GFAP mRNA and protein levels in ALF patients compared to controls. While the loss of EAAT-2 protein in ALF samples was post-translational in nature, EAAT-1 protein remained within normal limits. Immunohistochemistry confirmed that, in all cases, the losses of EAAT-2 and GFAP were uniquely astrocytic in their localization. AQP-4 mRNA expression was significantly increased and its immunohistochemistry demonstrated increased AQP-4 immunoreactivity in the glial end-feet process surrounding the microvessels. These findings provide evidence of selective alterations in the expression of genes coding for key astrocytic proteins implicated in central nervous system (CNS) excitability and brain edema in human ALF. We investigated the gene expression of astrocytic proteins involved in astrocyte swelling causing brain edema in autopsied brain tissues of patients with acute liver failure. This study demonstrated loss of GFAP expression and up-regulation of AQP-4 protein expression leading to cerebral edema, and loss of EAAT-2 expression implicated in excitatory neurotransmission. These findings may provide new drug targets against CNS complications of acute liver failure.
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Research Interests: Immunology, Medicine, Liver diseases, Biological Sciences, Humans, and 15 moreBiomedical science, Escherichia coli, Chronic Disease, Hepatitis C Virus, Hepatitis, Fibrosis, Plasmids, Antibody, Time Factors, Chronic Liver Disease, Neutralizing antibodies, Hepacivirus, Chronic hepatitis, reverse transcriptase polymerase chain reaction, and Medical and Health Sciences
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Research Interests: Biology, India, Experimental parasitology, Humans, Developing Country, and 15 moreFemale, Animals, Male, Amoebiasis, Infant, Gene, Experimental, Early Detection, Adult, Feces, Entamoeba histolytica, Cysteine endopeptidases, Amoebic Liver Abscess, Cysteine Proteinase Inhibitors, and gene amplification
Entamoeba histolytica infection still remains one of the major public health problem for developing countries like India. A rapid and accurate detection of this parasite is essential for prevention and control of amoebiasis. In this... more
Entamoeba histolytica infection still remains one of the major public health problem for developing countries like India. A rapid and accurate detection of this parasite is essential for prevention and control of amoebiasis. In this study, using the method of &amp;amp;amp;amp;amp;amp;amp;amp;#39;riboprinting&amp;amp;amp;amp;amp;amp;amp;amp;#39; (PCR-RFLP of rRNA genes from amoeba) we have analysed 15 stool samples from symptomatic patients of amoebiasis. All 15 patients of clinical amoebiasis had E. histolytica in their stool and two of the samples also showed mixed infection of E. dispar. Apart from the known restriction enzyme sites within the amoeba SSU-rRNA genes, a new Sau3A site having a discriminatory value is identified in these E. histolytica isolates from India. Hence, it is possible to rapidly identify E. histolytica DNA and differentiating it from E. dispar using minute amounts of clinical stool samples, thus eliminating the laborious parasite culturing process. Thus, riboprinting is advantageous for clearcut identification of E. histolytica in order to decide an effective antiamoebic therapy.
Research Interests: Microbiology, Biology, Public Health, Medicine, India, and 15 moreExperimental parasitology, Humans, Developing Country, Animals, Polymerase Chain Reaction, Amoebiasis, Experimental, Feces, Entamoeba histolytica, Veterinary Sciences, SSU rRNA, Entamoeba, restriction enzyme, Restriction Mapping, and Prevention and Control
Introduction. Hepatitis C virus (genotype-3) causes acute and chronic hepatitis infection predomination in India. The infectious phase of the virus requires various host factors for its survival and subsequent viral particle production.... more
Introduction. Hepatitis C virus (genotype-3) causes acute and chronic hepatitis infection predomination in India. The infectious phase of the virus requires various host factors for its survival and subsequent viral particle production. Small RNA molecules like microRNA-122 (miR-122) are one such factor mostly present in the liver and play a supportive role in viral replication.Objective. In this study, diagnostic potential of miR-122 is evaluated in the sera of chronic hepatitis C patients.Methods. miRNAs were isolated from the sera samples of patients as well as controls and miR-122 expression was quantified by real-time PCR.Results. A significant augmentation was observed in the level of circulating miR-122 (median level, 0.66 versus 0.29,P=0.001) in patients compared to controls with ROC value of0.929±0.034(P<0.001). Interestingly, miR-122 level also depicted a significant positive correlation with serum ALT (r=0.53), AST (r=0.44), and viral load (r=0.52).Conclusion. The stud...
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Acute rheumatic fever (ARF)/rheumatic heart disease (RHD) is a major cause of morbidity and mortality in India, yet, few studies are available on susceptibility markers. To associate human leukocyte antigen (HLA) class II alleles with... more
Acute rheumatic fever (ARF)/rheumatic heart disease (RHD) is a major cause of morbidity and mortality in India, yet, few studies are available on susceptibility markers. To associate human leukocyte antigen (HLA) class II alleles with north Indian RHD patients as genetic susceptibility markers. HLA alleles were analysed using sequence specific primer-polymerase chain reaction and nucleotide sequencing, while HLA-B27 expression by flowcytometry. Few HLA-DQB1/DRB1 alleles were associated with RHD and HLA-DRB1*14 gene polymorphism revealed two single nucleotide polymorphisms (SNPs) in patients. Bioinformatic predictions showed influence of SNPs on protein function. HLA-B27 was positive in 42.85% ARF patients. The study showed association of different HLA class II alleles with RHD in North Indian population.
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Research Interests: Medical Microbiology, Archives, Biology, Medicine, India, and 15 moreBiological Sciences, Phylogeny, Humans, Indian subcontinent, Disease Severity, Phylogenetic analysis, hepatitis E, Hepatitis E Virus, Seroprevalence, Outbreak, Fulminant, Severity of Illness Index, Molecular Sequence Data, Acute Disease, and Medical and Health Sciences
Research Interests: Biochemistry, Chemistry, Chromatography, Medicine, Cell line, and 15 moreHumans, Escherichia coli, Affinity chromatography, Free Energy, Molecular weight, Gel electrophoresis, Amino Acid Sequence, Polyacrylamide Gel Electrophoresis, Bacterial Adhesion, Binding Site, Size Exclusion Chromatography, Biochemistry and cell biology, Fluorescence quenching, Molecular Sequence Data, and High Molecular Weight
Background: Genome plasticity of Streptococcus pneumoniae is responsible for the reduced efficacy of various antibiotics and capsular polysaccharide based vaccines. Therefore targets independent of capsular types are sought to control the... more
Background: Genome plasticity of Streptococcus pneumoniae is responsible for the reduced efficacy of various antibiotics and capsular polysaccharide based vaccines. Therefore targets independent of capsular types are sought to control the pneumococcal pathogenicity. UcrDP-glucose pyrophosphorylase (UGPase) is one such desired candidate being responsible for the synthesis of UDP-glucose, a sugar-precursor in capsular biosynthesis and metabolic Leloir pathway. Being crucial to pneumococcal pathobiology, the effect of UGPase inhibition on virulence was evaluated in vitro. Methods: A putative inhibitor (UDP) was evaluated for effective inhibitory concentration in S. pneumoniae and A549 cells, its efficacy and toxicity. Effect of UDP on adherence and phagocytosis was measured in human respiratory epithelial (A549 and HEp-2) and macrophage (THP1 and J774.A.1) cell lines respectively. Results: A differential effective inhibitory concentration of UDP for UGPase inhibition was observed in S....
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Research Interests: Microbiology, Medical Microbiology, Biology, Virology, Medicine, and 15 moreIndia, Humans, Female, Male, Young Adult, Prevalence, Middle Aged, Genotype, Adult, Medical virology, Hepatitis B virus, Amino Acid Substitution Rates, Reverse Transcriptase, chronic hepatitis B, and multiplex polymerase chain reaction
A galactose-specific adhesin was isolated from the fimbriae of an enteroaggregative Escherichia coli (EAEC) strain. The adhesin was found to be a high molecular weight aggregate of the 18-kDa monomer. The dimeric (36 kDa) and tetrameric... more
A galactose-specific adhesin was isolated from the fimbriae of an enteroaggregative Escherichia coli (EAEC) strain. The adhesin was found to be a high molecular weight aggregate of the 18-kDa monomer. The dimeric (36 kDa) and tetrameric (76 kDa) forms appeared in sodium dodecyl sulphate polyacrylamide gel electrophoresis when a higher concentration of the adhesin was used. The IgGAD (IgG against adhesin) obtained from the immune sera raised in rabbits against purified adhesin could detect all three forms of the adhesin even from the crude fimbrial preparation. The IgGAD failed to recognize the adhesin in the presence of galactose, thereby suggesting the antibody-binding site and the sugar-binding site on the adhesin might be same or overlapping. Furthermore, the IgGAD could localize the adhesin exclusively on the fimbriae as observed in immunogold electron microscopy. The aggregative adherence of the bacteria to HEp-2 cells was reduced to 70% in the presence of the IgGAD. A glycoprotein (34 kDa) present in the membrane fraction of HEp-2 cells interacted with the purified adhesin in a galactose-specific manner. The IgGAD could recognize the adhesin from the crude fimbrial preparation of 9 out of 10 clinical isolates of EAEC strains but failed to identify any protein from the crude fimbrial preparation of Salmonella typhimurium (fim +ve as well as fim -ve strain), Vibrio cholerae (WO7) or Escherichia coli DH5alpha.