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 Identification and Characterization of Spontaneous Deletions within the Sp11-Sp12 Prophage Region of Escherichia coli O157:H7 Sakai

2013 ◽  
Vol 79 (6) ◽  
pp. 1934-1941 ◽  
Author(s):  
Chun Chen ◽  
Carrie R. Lewis ◽  
Kakolie Goswami ◽  
Elisabeth L. Roberts ◽  
Chitrita DebRoy ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Type Iii Secretion ◽  
Genomic Region ◽  
Escherichia Coli O157 ◽  
Content Type ◽  
E Coli ◽  
Food Borne ◽  
Genes Encoding ◽  
Identification And Characterization

ABSTRACTProphages make up 12% of the enterohemorrhagicEscherichia coligenome and play prominent roles in the evolution and virulence of this food-borne pathogen. Acquisition and loss of and rearrangements within prophage regions are the primary causes of differences in pulsed-field gel electrophoresis (PFGE) patterns among strains ofE. coliO157:H7. Sp11 and Sp12 are two tandemly integrated and putatively defective prophages carried byE. coliO157:H7 strain Sakai. In this study, we identified 3 classes of deletions that occur within the Sp11-Sp12 region, at a frequency of ca. 7.74 × 10−4. One deletion resulted in a precise excision of Sp11, and the other two spanned the junction of Sp11 and Sp12. All deletions resulted in shifts in the XbaI fragment pattern observed by PFGE. We sequenced the inducible prophage pool of Sakai but did not identify any mature phage particles corresponding to either Sp11 or Sp12. Deletions containingpchBandpsrC, which are Sp11-carried genes encoding proteins known or suspected to regulate type III secretion, did not affect the secretion levels of the EspA or EspB effector. Alignment of the Sp11-Sp12 DNA sequence with its corresponding regions in otherE. coliO157:H7 and O55:H7 strains suggested that homologous recombination rather than integrase-mediated excision is the mechanism behind these deletions. Therefore, this study provides a mechanism behind the previously observed genetic instability of this genomic region ofE. coliO157:H7.

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 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 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

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)

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.

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