scholarly journals Identification and Characterization of a New Porin Gene of Klebsiella pneumoniae: Its Role in β-Lactam Antibiotic Resistance

1999 ◽  
Vol 181 (9) ◽  
pp. 2726-2732 ◽  
Author(s):  
Antonio Doménech-Sánchez ◽  
Santiago Hernández-Allés ◽  
Luis Martínez-Martínez ◽  
Vicente J. Benedí ◽  
Sebastián Albertí
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Blot Analysis ◽  
Southern Blot Analysis ◽  
Functional Characterization ◽  
Standard Laboratory ◽  
Lactam Antibiotic ◽  
Resistant Strains ◽  
Identification And Characterization

ABSTRACT Klebsiella pneumoniae porin genes were analyzed to detect mutations accounting for the porin deficiency observed in many β-lactam-resistant strains. PCR and Southern blot analysis revealed the existence of a third porin gene in addition to the OmpK36 and OmpK35 porin genes previously described. This new porin gene was designated ompK37 and is present in all of the clinical isolates tested. The OmpK37 porin gene was cloned, sequenced, and overexpressed in Escherichia coli. In contrast to that of the major porins, OmpK37 porin expression was only detectable by Western blot analysis in porin-deficient β-lactam-resistant strains, suggesting strong down regulation under standard laboratory conditions. Functional characterization suggested a narrower pore for the OmpK37 porin than for K. pneumoniae porins OmpK36 and OmpK35. This correlated with the susceptibility to certain β-lactam antibiotics, since a K. pneumoniae strain expressing porin OmpK37, but not porin OmpK36 or OmpK35, was less susceptible to β-lactam antibiotics than the same strain expressing either porin OmpK36 or OmpK35.

scholarly journals Characterization of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae isolates from the community in Morocco

2011 ◽  
Vol 60 (9) ◽  
pp. 1344-1352 ◽  
Author(s):  
Abouddihaj Barguigua ◽  
Fatima El Otmani ◽  
Mustapha Talmi ◽  
Fatna Bourjilat ◽  
Fatima Haouzane ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Extended Spectrum

scholarly journals Identification and Functional Characterization of the p66/p68 Components of the MeCP1 Complex

2002 ◽  
Vol 22 (2) ◽  
pp. 536-546 ◽  
Author(s):  
Qin Feng ◽  
Ru Cao ◽  
Li Xia ◽  
Hediye Erdjument-Bromage ◽  
Paul Tempst ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Cpg Dinucleotides ◽  
Methylated Dna ◽  
Major Mechanism ◽  
Preferential Binding ◽  
Dna Silencing ◽  
The Individual ◽  
Identification And Characterization ◽  
Eukaryotic Genomes

ABSTRACT Methylation of cytosine at CpG dinucleotides is a common feature of many higher eukaryotic genomes. A major biological consequence of DNA methylation is gene silencing. Increasing evidence indicates that recruitment of histone deacetylase complexes by methyl-CpG-binding proteins is a major mechanism of methylated DNA silencing. We have previously reported that the MeCP1 protein complex represses transcription through preferential binding, remodeling, and deacetylation of methylated nucleosomes. To understand the molecular mechanism of the functioning of the MeCP1 complex, the individual components of the MeCP1 complex need to be characterized. In this paper, we report the identification and functional characterization of the p66 and p68 components of the MeCP1 complex. We provide evidence that the two components are different forms of the same zinc finger-containing protein. Analysis of the p66 homologs from different organisms revealed two highly conserved regions, CR1 and CR2. While CR1 is involved in the association of p66 with other MeCP1 components, CR2 plays an important role in targeting p66 and MBD3 to specific loci. Thus, our study not only completes the identification of the MeCP1 components but also reveals the potential function of p66 in MeCP1 complex targeting. The identification and characterization of all the MeCP1 components set the stage for reconstitution of the MeCP1 complex.

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

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