scholarly journals Isolation and characterization of the cytochrome domain of flavocytochrome b2 expressed independently in Escherichia coli

1992 ◽  
Vol 283 (1) ◽  
pp. 87-90 ◽  
Author(s):  
C E Brunt ◽  
M C Cox ◽  
A G P Thurgood ◽  
G R Moore ◽  
G A Reid ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Field ◽  
Cytochrome B5 ◽  
Microsomal Cytochrome ◽  
E Coli ◽  
Flavocytochrome B2 ◽  
Isolation And Characterization ◽  
Exchange Rate Constant ◽  
Microsomal Cytochrome B5

The cytochrome domain of flavocytochrome b2 (L-lactate dehydrogenase) was expressed in the bacterium Escherichia coli and a purification procedure was developed. When expressed in E. coli, the b2-cytochrome domain contains protohaem IX and has an electronic absorption spectrum identical with that of the cytochrome b2 ‘core’ produced by proteolytic cleavage of the enzyme isolated from yeast. The b2-cytochrome domain isolated from E. coli has an Mr of 10,500 and a redox potential of -31 +/- 2 mV. High-field n.m.r. studies indicate pKa values for the haem propionate groups to be 4.8 and 4.6, consistent with these groups being exposed to solvent rather than buried inside the protein. Using n.m.r. spectroscopy, we have determined an electron self-exchange rate constant for the b2-cytochrome domain of 2.3 x 10(6) M-1.s-1, which is more than two orders of magnitude larger than the value obtained for microsomal cytochrome b5, a homologue of b2-cytochrome domain.

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

scholarly journals Isolation and characterization of a novel bacteriophage, Kapi1, capable of O-antigen modification in commensal Escherichia coli.

2021 ◽  
Author(s):  
Kat Pick ◽  
Tracy Lyn Raivio
Keyword(s):  
Escherichia Coli ◽  
Molecular Mechanisms ◽  
Shigella Flexneri ◽  
Model System ◽  
Temperate Phage ◽  
Phage Displays ◽  
E Coli ◽  
O Antigen ◽  
Isolation And Characterization

In this study, we describe the isolation and characterization of novel bacteriophage Kapi1 (vB_EcoP_Kapi1) isolated from a strain of commensal Escherichia coli inhabiting the gastrointestinal tract of healthy mice. We show that Kapi1 is a temperate phage integrated into tRNA argW of strain MP1 and describe its genome annotation and structure. Kapi1 shows limited homology to other characterized prophages but is most similar to the phages of Shigella flexneri, and clusters taxonomically with P22-like phages. Investigation of the lifestyle of Kapi1 shows that this phage displays unstable lysogeny and influences the growth of its host. The receptor for Kapi1 is the lipopolysaccharide O-antigen, and we further show that Kapi1 alters the structure of its hosts O-antigen in multiple ways. We hope to use MP1 and Kapi1 as a model system to explore molecular mechanisms of mammalian colonization by E. coli and ask what the role(s) of prophages in this context might be.

scholarly journals Isolation and characterization of Escherichia coli phage and enhance its bactericidal activity that collaborative with kanamycin sulfate

2020 ◽  
Author(s):  
Liming Jiang ◽  
Rui Zheng
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Bactericidal Activity ◽  
Therapeutic Potential ◽  
Health Concern ◽  
Low Concentration ◽  
E Coli ◽  
Kanamycin Sulfate ◽  
Isolation And Characterization

Abstract Background: Escherichia coli is the most important and widespread bacteria in worldwide, which mainly found in contaminated food, human and animal faeces. Unfortunately, Some of E. coli strains are multidrug-resistant (MDR) pathogen leading significant public health concern globally. Biofilm is a multicellular community of microorganisms. Phages and their derivatives are ideal candidates for replacing or compensating for antibiotic problems in the future. Method: Here, we aimed to isolation and characterization of Escherichia coli phage and research its bactericidal activity that individually or collaborative with kanamycin sulfateResults: In this study, three virulent phages Flora, T4 and WJ were isolated from the laboratory and drug sample in Wuxi, China. It’s belonged to the Myoviridae family and optimum temperature is 42 ℃, optimum pH= 7, optimum MOI is 0.0001 and the genome size of Flora, T4 and WJ were 168, 909, 168903 and 168, 900 bp respectively. Flora has two exonuclease, whereas T4 and WJ have only one. Antibiotics have better bactericidal activity than phages in a low concentration medium of bacteria, nonetheless, phages have better bactericidal activity than antibiotics in a high concentration of bacteria, and that, collaboration of phages and antibiotics have better bactericidal activity effect than alone of phages or antibiotics in a low concentration medium of bacteria. Conclusion: The excellent performance of phage Flora for its therapeutic potential on clinic. The data of this study provided the strong evidence that the application of phage could reduce the growth and biofilm of E. coli that are important to maintain public health. Keywords: Escherichia coli, phage, lytic spectrum, biofilm, antibiotic

scholarly journals ISOLATION AND CHARACTERIZATION OF ESCHERICHIA COLI FROM BUFFALO CALVES IN SOME SELECTED AREAS OF BANGLADESH

1970 ◽  
Vol 8 (1) ◽  
pp. 23-26 ◽  
Author(s):  
SK Paul ◽  
MSR Khan ◽  
MA Rashid ◽  
J Hassan ◽  
SMS Mahmud
Keyword(s):  
Escherichia Coli ◽  
Nalidixic Acid ◽  
Rectal Swab ◽  
Antibiotic Sensitivity ◽  
Buffalo Calves ◽  
E Coli ◽  
Isolation And Characterization ◽  
Sensitivity Pattern ◽  
Highly Sensitive

The research works was conducted with a view to isolate and identify the Escherichia coli (E. coli) organism from diarrhoeic cases of buffalo reared in selected areas of Bangladesh as well the prevalence and antibiotic sensitivity pattern of the isolated E. coli in the Department of Microbiology and Hygiene, Bangladesh Agricultural University (BAU), Mymensingh-2202 during the period from April 2008 to May 2009. A total of 50 rectal swab samples were collected from 4 different places namely Haluaghat and Boira of Mymensingh, Madupur of Tangail and Kazipur of Sirajgonj districts. The samples were aseptically carried to the laboratory of the Department of Microbiology and Hygiene and subjected to different cultural, morphological and biochemical examinations. Upon cultural, morphological and biochemical examinations 23 (45%) samples were found to be positive for E. coli. The highest prevalence was found in Haluaghat, Mymensingh (53.33%) and the lowest (40.00%) in Boira, Mymensingh and Kazipur, Sirajganj. Antibiogram study revealed that the isolated E. coli was highly sensitive to Enrofloxacin and Ciprofloxacin, moderately sensitive to Cefalexin and Amoxicillin, and resistant to Nalidixic acid and Erythromycin. DOI = 10.3329/bjvm.v8i1.7398 Bangl. J. Vet. Med. (2010). 8(1): 23-26

Isolation and characterization of Hfr strains of Erwinia amylovora

1978 ◽  
Vol 24 (4) ◽  
pp. 448-454 ◽  
Author(s):  
Balappa K. Pugashetti ◽  
Arun K. Chatterjee ◽  
Mortimer P. Starr
Keyword(s):  
Escherichia Coli ◽  
Acridine Orange ◽  
High Frequency ◽  
Erwinia Amylovora ◽  
Donor Cell ◽  
E Coli ◽  
Isolation And Characterization

Hfr strains (Hfr 159 and its derivatives, Hfr 160 and Hfr 161) were constructed from Erwinia amylovora ICPB EA178 by introducing an Escherichia coli F′his+ plasmid and then selecting for integration of F′his+ after treatment with acridine orange. The Hfr strains were relatively stable upon repeated transfers on nonselective media. Interrupted mating experiments and analyses of inheritance of unselected markers showed that his+ is transferred by Hfr 159 as the proximal marker at a relatively high frequency (about 5 × 10−4 recombinants per input donor cell), followed by ilv+, orn+, arg+, pro+, rbs+, met+, trp+, leu+, ser+, and thr+ (not necessarily in that precise order). The donor strains, previously constructed in E. amylovora by integration of F'lac+ from E. coli, transfer cys+ as the proximal marker followed by ser+. Further analysis of one of those earlier donor strains, Hfr 99, showed that ser+ is followed by arg+, orn+, met+, pro+, leu+, ilv+, rbs+, his+, trp+, and thr+ (not necessarily in that precise order). Thus, the Hfr strains constructed by integration of F′his+ are different, in terms of origin and direction of transfer, from those derived from integration of F′lac+. The applicability of these Hfr strains to mapping the genes on the E. amylovora chromosome is indicated.

Isolation and characterization of a bacteriophage infective for a UDP-galactose-4-epimeraseless mutant of Escherichia coli

1975 ◽  
Vol 21 (8) ◽  
pp. 1217-1223 ◽  
Author(s):  
Christopher J. Pazoles ◽  
Charles F. Kulpa Jr.
Keyword(s):  
Escherichia Coli ◽  
Cell Membrane ◽  
Receptor Site ◽  
Bacterial Strains ◽  
Adsorption Studies ◽  
E Coli ◽  
Isolation And Characterization

A DNA bacteriophage, designated CP13, was isolated against Escherichia coli J5, a UDP-galactose-4-epimeraseless mutant of E. coli 0111:B4. Bacteriophage CP13 appears to be specific for rough bacterial strains. Adsorption studies with E. coli J5 grown with galactose show that the bacteriophage will not adsorb when complete lipopolysaccharide is present in the cell membrane. This indicates that lipopolysaccharide may be directly or indirectly involved with the receptor site for bacteriophage CP13. The bacteriophage DNA has a G + C content of 52%.

scholarly journals Isolation of Generalized Transducing Bacteriophages for Uropathogenic Strains of Escherichia coli

2011 ◽  
Vol 77 (18) ◽  
pp. 6630-6635 ◽  
Author(s):  
E. J. Battaglioli ◽  
G. A. Baisa ◽  
A. E. Weeks ◽  
R. A. Schroll ◽  
A. J. Hryckowian ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance Gene ◽  
Treatment Plant ◽  
Content Type ◽  
E Coli ◽  
Multiple Loci ◽  
Isolation And Characterization ◽  
Strain Cft073 ◽  
K 12

ABSTRACTThe traditional genetic procedure for random or site-specific mutagenesis inEscherichia coliK-12 involves mutagenesis, isolation of mutants, and transduction of the mutation into a clean genetic background. The transduction step reduces the likelihood of complications due to secondary mutations. Though well established, this protocol is not tenable for many pathogenicE. colistrains, such as uropathogenic strain CFT073, because it is resistant to known K-12 transducing bacteriophages, such as P1. CFT073 mutants generated via a technique such as lambda Red mutagenesis may contain unknown secondary mutations. Here we describe the isolation and characterization of transducing bacteriophages for CFT073. Seventy-seven phage isolates were acquired from effluent water samples collected from a wastewater treatment plant in Madison, WI. The phages were differentiated by a host sensitivity-typing scheme with a panel ofE. colistrains from the ECOR collection and clinical uropathogenic isolates. We found 49 unique phage isolates. These were then examined for their ability to transduce antibiotic resistance gene insertions at multiple loci between different mutant strains of CFT073. We identified 4 different phages capable of CFT073 generalized transduction. These phages also plaque on the model uropathogenicE. colistrains 536, UTI89, and NU14. The highest-efficiency transducing phage, ΦEB49, was further characterized by DNA sequence analysis, revealing a double-stranded genome 47,180 bp in length and showing similarity to other sequenced phages. When combined with a technique like lambda Red mutagenesis, the newly characterized transducing phages provide a significant development in the genetic tools available for the study of uropathogenicE. coli.

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