Identification and characterization of IS1 transposition in plasmid amplification mutants of E. coli clones producing DNA vaccines

2006 ◽  
Vol 73 (4) ◽  
pp. 815-826 ◽  
Author(s):  
Kristala L. Jones Prather ◽  
M. Celina Edmonds ◽  
Jerrell W. Herod
Keyword(s):  
Dna Vaccines ◽  
E Coli ◽  
Identification And Characterization ◽  
Plasmid Amplification ◽  
Is1 Transposition

scholarly journals Isolation and characterization of escherichia coli in ready-to-eat foods vended in Islamic University, Kushtia

1970 ◽  
Vol 18 ◽  
pp. 99-103 ◽  
Author(s):  
S Biswas ◽  
MAK Parvez ◽  
M Shafiquzzaman ◽  
S Nahar ◽  
MN Rahman
Keyword(s):  
Escherichia Coli ◽  
Pattern Analysis ◽  
University Campus ◽  
Rflp Pattern ◽  
E Coli ◽  
Fish Meat ◽  
Isolation And Characterization ◽  
Food Borne ◽  
Identification And Characterization

Context: Escherichia coli is shed in the feces of warm blooded animals and humans and thus potential for public health. Detection and characterization of E. coli in the ready-to-eat (RTE) foods concerns due to their presence indicates fecal contamination of the food.   Objective: To identify, characterize and RFLP pattern analysis of E. coli isolated from RTE foods vended in Islamic University campus, Kushtia.   Materials and Methods: Fifty samples from four types of consumed foods in six student halls of residence, some temporary restaurants of Islamic University, Kushtia were assessed for bacterial contamination by standard methods. Identification and characterization of E. coli isolates were performed using IMViC tests. Genomic DNA was used to perform RFLP pattern analysis.   Results: Thirty seven out of 50 (74%) examined samples of RTE foods had E. coli contamination. The highest number of E. coli was isolated from vegetable oriented RTE foods (90.90%) and fish, meat and cereals samples were also significantly E. coli positive. RFLP profiling of two E. coli isolates were observed.   Conclusion: The results of this study provide evidence that some RTE foods had unsatisfactory levels of contamination with E. coli. Thus street vended RTE food could be important potential vehicles for food-borne diseases. Molecular characterization may be exploited to identify food borne pathogen among different species.  Keywords: Ready-to-eat foods; Escherichia coli; RFLP pattern DOI: http://dx.doi.org/10.3329/jbs.v18i0.8783 JBS 2010; 18(0): 99-103

Identification and characterization of four new tra cistrons on the E. coli K12 sex factor F

Plasmid ◽  
1978 ◽  
Vol 1 (3) ◽  
pp. 316-323 ◽  
Author(s):  
T. Miki ◽  
T. Horiuchi ◽  
N.S. Willetts
Keyword(s):  
E Coli ◽  
Identification And Characterization

scholarly journals Postgenomic Scan of Metallo-β-Lactamase Homologues in Rhizobacteria: Identification and Characterization of BJP-1, a Subclass B3 Ortholog from Bradyrhizobium japonicum

2006 ◽  
Vol 50 (6) ◽  
pp. 1973-1981 ◽  
Author(s):  
Magdalena Stoczko ◽  
Jean-Marie Frère ◽  
Gian Maria Rossolini ◽  
Jean-Denis Docquier
Keyword(s):  
Bradyrhizobium Japonicum ◽  
Catalytic Efficiency ◽  
Open Reading Frames ◽  
Human Pathogens ◽  
Microbial Genomes ◽  
E Coli ◽  
Genes Encoding ◽  
And Function ◽  
Identification And Characterization

ABSTRACT The diffusion of metallo-β-lactamases (MBLs) among clinically important human pathogens represents a therapeutic issue of increasing importance. However, the origin of these resistance determinants is largely unknown, although an important number of proteins belonging to the MBL superfamily have been identified in microbial genomes. In this work, we analyzed the distribution and function of genes encoding MBL-like proteins in the class Rhizobiales. Among 12 released complete genomes of members of the class Rhizobiales, a total of 57 open reading frames (ORFs) were found to have the MBL conserved motif and identity scores with MBLs ranging from 8 to 40%. On the basis of the best identity scores with known MBLs, four ORFs were cloned into Escherichia coli for heterologous expression. Among their products, one (blr6230) encoded by the Bradyrhizobium japonicum USDA110 genome, named BJP-1, hydrolyzed β-lactams when expressed in E. coli. BJP-1 enzyme is most closely related to the CAU-1 enzyme from Caulobacter vibrioides (40% amino acid sequence identity), a member of subclass B3 MBLs. A kinetic analysis revealed that BJP-1 efficiently hydrolyzed most β-lactam substrates, except aztreonam, ticarcillin, and temocillin, with the highest catalytic efficiency measured with meropenem. Compared to other MBLs, BJP-1 was less sensitive to inactivation by chelating agents.

scholarly journals Identification and Characterization of an Archaeon-Specific Riboflavin Kinase

2008 ◽  
Vol 190 (7) ◽  
pp. 2615-2618 ◽  
Author(s):  
Zahra Mashhadi ◽  
Hong Zhang ◽  
Huimin Xu ◽  
Robert H. White
Keyword(s):  
Escherichia Coli ◽  
Metal Ion ◽  
Biosynthetic Pathway ◽  
Recombinant Expression ◽  
Cell Extract ◽  
Flavin Mononucleotide ◽  
E Coli ◽  
Gene Recombinant ◽  
Identification And Characterization

ABSTRACT The riboflavin kinase in Methanocaldococcus jannaschii has been identified as the product of the MJ0056 gene. Recombinant expression of the MJ0056 gene in Escherichia coli led to a large increase in the amount of flavin mononucleotide (FMN) in the E. coli cell extract. The unexpected features of the purified recombinant enzyme were its use of CTP as the phosphoryl donor and the absence of a requirement for added metal ion to catalyze the formation of FMN. Identification of this riboflavin kinase fills another gap in the archaeal flavin biosynthetic pathway. Some divalent metals were found to be potent inhibitors of the reaction. The enzyme represents a unique CTP-dependent family of kinases.

scholarly journals Identification and Characterization of a New Lipoprotein, NlpI, in Escherichia coli K-12

1999 ◽  
Vol 181 (14) ◽  
pp. 4318-4325 ◽  
Author(s):  
Masaru Ohara ◽  
Henry C. Wu ◽  
Krishnan Sankaran ◽  
Paul D. Rick
Keyword(s):  
Escherichia Coli ◽  
Direct Consequence ◽  
Insertion Mutant ◽  
Polynucleotide Phosphorylase ◽  
Wild Type ◽  
E Coli ◽  
K 12 ◽  
Identification And Characterization ◽  
Lines Of Evidence

ABSTRACT We report here the identification of a new lipoprotein, NlpI, inEscherichia coli K-12. The NlpI structural gene (nlpI) is located between the genes pnp(polynucleotide phosphorylase) and deaD (RNA helicase) at 71 min on the E. coli chromosome. The nlpI gene encodes a putative polypeptide of approximately 34 kDa, and multiple lines of evidence clearly demonstrate that NlpI is indeed a lipoprotein. An nlpI::cm mutation rendered growth of the cells osmotically sensitive, and incubation of the insertion mutant at an elevated temperature resulted in the formation of filaments. The altered phenotype of the mutant was a direct consequence of the mutation in nlpI, since it was complemented by the wild-type nlpI gene alone. Overexpression of the unaltered nlpI gene in wild-type cells resulted in the loss of the rod morphology and the formation of single prolate ellipsoids and pairs of prolate ellipsoids joined by partial constrictions. NlpI may be important for an as-yet-undefined step in the overall process of cell division.

scholarly journals Prevalence and characterization of multi-drug resistant Escherichia coli from urine samples

1970 ◽  
Vol 20 (1) ◽  
pp. 23-30
Author(s):  
Augustin Kakon Gomes ◽  
Humaira Akhter ◽  
Belal Mahmud ◽  
Sirajul Islam Khan ◽  
Anowara Begum
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Profile Analysis ◽  
Plasmid Profile ◽  
Urine Samples ◽  
Drug Resistant ◽  
Methyl Red ◽  
E Coli ◽  
Identification And Characterization

Isolation, identification and characterization of Escherichia coli were carried out in terms of biochemical, serological, antibiogram, plasmid profile and culture condition of urine samples. Out of 50 urine samples, 36 were positive for E. coli that were confirmed by biochemical (e.g. oxidase, kligler’s iron agar, indole, methyl red-voges proskauer and citrate utilization) tests and 4-methyl-umbelliferyl-β-D-glucoronide (MUG) test. Twenty seven strains gave positive result with different antisera whereas nine strains were untypable (UT), respectively. Thirty six strains were also tested by antibiogram against ten different antibiotics. Most E. coli strains were resistant to bacitracin, ampicillin, novobiocin, kanamycin and streptomycin. Eighty three per cent strains were sensitive to ciprofloxacin and gentamycin while 11 and 12% showed resistance to ciprofloxacin and gentamycin, respectively. By plasmid profile analysis of the 36 strains seven different plasmid patterns were observed. Comparison of the plasmid profiles with the antibiogram results indicated the presence of resistant (R) plasmid. Thirty four isolates of E. coli contained a common 25 kb plasmid that may possibly be responsible for drug resistance in this study. The results suggested that the prevalence of multi-drug resistant and new serotype of E. coli may be increasing rapidly which is alarming for treatment of urinary tract infection in Bangladesh.Key words: Prevalence; Characterization; E. coli; Multi-drug resistant; Serotype; Clinical sampleDOI: http://dx.doi.org/10.3329/dujbs.v20i1.8834Dhaka Univ. J. Biol. Sci. 20(1): 23-30, 2011 (January)

scholarly journals Two bacterial glycosphingolipid synthases responsible for the synthesis of glucuronosylceramide and α-galactosylceramide

2020 ◽  
Vol 295 (31) ◽  
pp. 10709-10725
Author(s):  
Nozomu Okino ◽  
Mengbai Li ◽  
Qingjun Qu ◽  
Tomoko Nakagawa ◽  
Yasuhiro Hayashi ◽  
...  
Keyword(s):  
Gel Filtration ◽  
Homologous Gene ◽  
Bacterial Physiology ◽  
E Coli ◽  
Donor And Acceptor ◽  
Low Levels ◽  
Killer T Cells ◽  
Invariant Natural Killer ◽  
Identification And Characterization

Bacterial glycosphingolipids such as glucuronosylceramide and galactosylceramide have been identified as ligands for invariant natural killer T cells and play important roles in host defense. However, the glycosphingolipid synthases required for production of these ceramides have not been well-characterized. Here, we report the identification and characterization of glucuronosylceramide synthase (ceramide UDP-glucuronosyltransferase [Cer-GlcAT]) in Zymomonas mobilis, a Gram-negative bacterium whose cellular membranes contain glucuronosylceramide. On comparing the gene sequences that encode the diacylglycerol GlcAT in bacteria and plants, we found a homologous gene that is widely distributed in the order Sphingomonadales in the Z. mobilis genome. We first cloned the gene and expressed it in Escherichia coli, followed by protein purification using nickel–Sepharose affinity and gel filtration chromatography. Using the highly enriched enzyme, we observed that it has high glycosyltransferase activity with UDP-glucuronic acid and ceramide as sugar donor and acceptor substrate, respectively. Cer-GlcAT deletion resulted in a loss of glucuronosylceramide and increased the levels of ceramide phosphoglycerol, which was expressed in WT cells only at very low levels. Furthermore, we found sequences homologous to Cer-GlcAT in Sphingobium yanoikuyae and Bacteroides fragilis, which have been reported to produce glucuronosylceramide and α-galactosylceramide, respectively. We expressed the two homologs of the cer-glcat gene in E. coli and found that each gene encodes Cer-GlcAT and Cer-galactosyltransferase, respectively. These results contribute to the understanding of the roles of bacterial glycosphingolipids in host–bacteria interactions and the function of bacterial glycosphingolipids in bacterial physiology.

Identification and Characterization of Salmonella Isolates by Automated Ribotyping†

1998 ◽  
Vol 61 (5) ◽  
pp. 519-524 ◽  
Author(s):  
THOMAS P. OSCAR
Keyword(s):  
Ribosomal Rna ◽  
Dna Probe ◽  
Strain Level ◽  
Reference Laboratory ◽  
E Coli ◽  
Genus Level ◽  
Typing Methods ◽  
Automated Ribotyping ◽  
Identification And Characterization

A study was conducted with the RiboPrinter, an automated ribotyping system, to evaluate its ability to identify and characterize isolates of Salmonella from broiler operations. Isolates of Salmonella obtained from a local broiler company were serotyped by a reference laboratory and ribotyped using the RiboPrinter. The RiboPrinter generated ribotype patterns by probing EcoRI digests of Salmonella DNA with an E. coli DNA probe to the ribosomal RNA operon. The RiboPrinter identified isolates by band matching of their ribotype patterns to ribotype patterns in its database. In addition, the RiboPrinter characterized isolates by sorting them into ribotypes on the basis of the similarity of their ribotype patterns. Of 117 isolates, the RiboPrinter identified 34 (29%) at the serotype level, 11 (9%) at the strain level, 46 (39%) at the genus level, and 26 (22%) were not identified. Thus, only 38% of the isolates were identified at or below the serotype level, indicating that the RiboPrinter was limited in its ability to identify Salmonella isolates by band matching. In contrast, the RiboPrinter was very effective at characterizing Salmonella isolates. Out of 108 isolates, the RiboPrinter detected 31 ribotypes, compared to serotyping which only detected 22 types of Salmonella. Thus, automated ribotyping was more discriminatory than serotyping. However, when results of both typing methods were combined, 40 types of Salmonella were detected, indicating that the best discrimination was obtained when automated ribotyping and serotyping were used together.

scholarly journals Identification and characterization of pathogenic E. coli -specific bacteriophages and polyvalent bacteriophages in piglet gut with increasing coliphage numbers after weaning

2021 ◽  
Author(s):  
Yan Lin ◽  
Bei Zhou ◽  
Weiyun Zhu
Keyword(s):  
Bacterial Communities ◽  
Biological Significance ◽  
Metagenomic Sequencing ◽  
Biological Characterization ◽  
E Coli ◽  
Intestinal Physiology ◽  
Faecal Samples ◽  
Pig Farms ◽  
Identification And Characterization

Post-weaning diarrhoea in pigs is mainly caused by pathogenic Escherichia coli and is a major source of revenue loss to the livestock industry. Bacteriophages dominate the gut virome and have the potential to regulate bacterial communities and thus influence the intestinal physiology. To determine the biological characterization of intestinal coliphages, we isolated and identified the faecal coliphages of healthy pre-weaned and post-weaned piglets from Nanjing and Chuzhou pig farms. First, ahead of coliphage isolation, 87 E. coli strains were isolated from healthy or diarrheal faecal samples from three pig farms, of which 8 were pathogenic strains including ETEC and EPEC. 87.3% of E. coli strains possessed drug resistance against three antibiotics. Using these 87 E. coli strains as indicator hosts, we isolated 45 coliphages and found a higher presence in the post-weaning stage than pre-weaning stage (24 vs 17 in Nanjing farm, 13 vs 4 in Chuzhou farm). Further more, each farm had a one most prevalent coliphage strain. Pathogenic E. coli -specific bacteriophages were commonly detected (9/10 samples in Nanjing farm, 7/10 in Chuzhou farm) in guts of sampled piglet and most had significant bacteriostatic effects ( P < 0.05) on pathogenic E. coli strains. Three polyvalent bacteriophages (N24, N30, and C5) were identified. The N30 and C5 strains showed a genetic identity of 89.67% with mild differences in infection characteristics. Our findings suggest that pathogenic E. coli -specific bacteriophages as well as polyvalent bacteriophages are commonly present in piglet gut and that weaning is an important event that affects coliphage numbers. IMPORTANCE Previous studies based on metagenomic sequencing reported that gut bacteriophages profoundly influence gut physiology but did not provide information regarding the host range and biological significance. Here, we screened coliphages from pre-weaned and post-weaned piglet gut against indicator hosts, which allowed us to identify the pathogenic E. coli -specific bacteriophages and polyvalent bacteriophages in pig farms and quantify their presence. Our approach complements sequencing methods and provides new insights into the biological characterizations of bacteriophage in the gut along with the ecological effects of intestinal bacteriophages.

scholarly journals Identification and Characterization of Escherichia coli from Bronchial Plug of Broiler Chicken with Respiratory Distress

2021 ◽  
Vol 10 (10) ◽  
pp. 221-228
Author(s):  
M. H. Chhatrola D. T. Fefar ◽  
A. R. Bhadaniya B. J. Trangadia ◽  
V. A. Kalaria S. N. Ghodasara ◽  
B. B. Javia J. M. Chauhan
Keyword(s):  
Respiratory Distress ◽  
Broiler Chicken ◽  
Pcr Assay ◽  
E Coli ◽  
Methane Sulphonate ◽  
Highly Sensitive ◽  
High Prevalence ◽  
Identification And Characterization ◽  
Pooled Sample

A Twenty-five bronchial plug samples from dead broiler chicken with signs of respiratory distress collected for identification of avian pathogenic E. coli (APEC). Samples comprised of one pooled sample each from 25 poultry farms located in and around Junagadh city. Isolation, culture and colony characteristics used for primary detection followed by PCR assay targeting four virulence genes (iss, papC, tsh and vat)for confirmatory diagnosis. All bronchial plugs were found to be positive for E. coli infection by isolation. Out of 25 flock sampled, the highest number of E. coli isolates were found positive for the presence of iss gene (22) followed by tsh gene (15), vat gene (13) and papC gene (8)by PCR. On antibiogram, overall E. coli was highly sensitive to colistin (Methane sulphonate) and meropenem(100%) followed by levofloxacin (76%), ceftriaxone (64%), gentamicin (60%), amikacin (60%), co-trimoxazole (40%), amoxycilin-clavunic acid (8%) and imepenem (8%). These results indicated the high prevalence of the E. coli with variable antibiotic resistance in broiler chicken.

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