scholarly journals HIGH PREVALENCE OF CLASS I AND CLASS II INTEGRONS IN UROPATHOGENIC E. COLI STRAINS (UPECs) AND THEIR RELATIONSHIP WITH ANTIBIOTIC RESISTANCE, PHYLOGENY AND VIRULENCE

2021 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
Defne Gümüş ◽  
Fatma Kalaycı Yüksek ◽  
Firdevs Camadan ◽  
Merve Oral ◽  
Aslı Macunluoğlu ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Class Ii ◽  
Class I ◽  
E Coli ◽  
High Prevalence

scholarly journals Purification and characterization of two fructose diphosphate aldolases from Escherichia coli (Crookes' strain)

1973 ◽  
Vol 131 (4) ◽  
pp. 833-841 ◽  
Author(s):  
Donald Stribling ◽  
Richard N. Perham
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Metal Ions ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Class Ii ◽  
Class I ◽  
E Coli ◽  
Km Value ◽  
Bivalent Metal Ions

Two fructose diphosphate aldolases (EC 4.1.2.13) were detected in extracts of Escherichia coli (Crookes' strain) grown on pyruvate or lactate. The two enzymes can be resolved by chromatography on DEAE-cellulose at pH7.5, or by gel filtration on Sephadex G-200, and both have been obtained in a pure state. One is a typical bacterial aldolase (class II) in that it is strongly inhibited by metal-chelating agents and is reactivated by bivalent metal ions, e.g. Ca2+, Zn2+. It is a dimer with a molecular weight of approx. 70000, and the Km value for fructose diphosphate is about 0.85mm. The other aldolase is not dependent on metal ions for its activity, but is inhibited by reduction with NaBH4 in the presence of substrate. The Km value for fructose diphosphate is about 20μm (although the Lineweaver–Burk plot is not linear) and the enzyme is probably a tetramer with molecular weight approx. 140000. It has been crystallized. On the basis of these properties it is tentatively assigned to class I. The appearance of a class I aldolase in bacteria was unexpected, and its synthesis in E. coli is apparently favoured by conditions of gluconeogenesis. Only aldolase of class II was found in E. coli that had been grown on glucose. The significance of these results for the evolution of fructose diphosphate aldolases is briefly discussed.

scholarly journals A combination of Class-I fumarases and metabolites (α-ketoglutarate and fumarate) signal the DNA damage response in Escherichia coli

2021 ◽  
Vol 118 (23) ◽  
pp. e2026595118
Author(s):  
Yardena Silas ◽  
Esti Singer ◽  
Koyeli Das ◽  
Norbert Lehming ◽  
Ophry Pines
Keyword(s):  
Dna Damage ◽  
Dna Damage Response ◽  
Dna Damage Repair ◽  
Class Ii ◽  
Class I ◽  
Repair Enzyme ◽  
E Coli ◽  
Damage Repair ◽  
Damage Response ◽  
Null Mutants

Class-II fumarases (fumarate hydratase, FH) are dual-targeted enzymes occurring in the mitochondria and cytosol of all eukaryotes. They are essential components in the DNA damage response (DDR) and, more specifically, protect cells from DNA double-strand breaks. Similarly, the gram-positive bacterium Bacillus subtilis class-II fumarase, in addition to its role in the tricarboxylic acid cycle, participates in the DDR. Escherichia coli harbors three fumarase genes: class-I fumA and fumB and class-II fumC. Notably, class-I fumarases show no sequence similarity to class-II fumarases and are of different evolutionary origin. Strikingly, here we show that E. coli fumarase functions are distributed between class-I fumarases, which participate in the DDR, and the class-II fumarase, which participates in respiration. In E. coli, we discover that the signaling molecule, alpha-ketoglutarate (α-KG), has a function, complementing DNA damage sensitivity of fum-null mutants. Excitingly, we identify the E. coli α-KG–dependent DNA repair enzyme AlkB as the target of this interplay of metabolite signaling. In addition to α-KG, fumarate (fumaric acid) is shown to affect DNA damage repair on two different levels, first by directly inhibiting the DNA damage repair enzyme AlkB demethylase activity, both in vitro and in vivo (countering α-KG). The second is a more global effect on transcription, because fum-null mutants exhibit a decrease in transcription of key DNA damage repair genes. Together, these results show evolutionary adaptable metabolic signaling of the DDR, in which fumarases and different metabolites are recruited regardless of the evolutionary enzyme class performing the function.

scholarly journals Multi-Drug Resistant Plasmids with ESBL/AmpC and mcr-5.1 in Paraguayan Poultry Farms: The Linkage of Antibiotic Resistance and Hatcheries

2021 ◽  
Vol 9 (4) ◽  
pp. 866
Author(s):  
Kristina Nesporova ◽  
Adam Valcek ◽  
Costas Papagiannitsis ◽  
Iva Kutilova ◽  
Ivana Jamborova ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Common Source ◽  
Drug Resistant ◽  
E Coli ◽  
High Prevalence ◽  
Poultry Farms ◽  
Complete Sequences ◽  
Group D ◽  
Sequence Types ◽  
Shed Light

Poultry represents a common source of bacteria with resistance to antibiotics including the critically important ones. Selective cultivation using colistin, cefotaxime and meropenem was performed for 66 chicken samples coming from 12 farms in Paraguay while two breeding companies supplied the farms. A total of 62 Escherichia coli and 22 Klebsiella pneumoniae isolates were obtained and representative isolates were subjected to whole-genome sequencing. Relatively high prevalence of phylogenetic group D and F was observed in E. coli isolates and several zoonotic sequence types (STs) including ST457 (14 isolates), ST38 (5), ST10 (2), ST117 (2) or ST93 (4) were detected. Isolates from three farms, which purchased chicken from a Paraguayan hatchery showed higher prevalence of mcr-5.1 and blaCTX-M-8 compared to the other nine farms, which purchased chickens from a Brazilian hatchery. Moreover, none of the K. pneumoniae isolates were linked to the Paraguayan hatchery. ESBL/AmpC and mcr-5-carrying multi-drug resistant (MDR) plasmids were characterized, and complete sequences were obtained for eight plasmids. The study shed light on Paraguayan poultry farms as a reservoir of antibiotic resistance commonly conferred via MDR plasmids and showed linkage between resistance and origin of the chickens at the hatcheries level.

scholarly journals Prevalence of Antibiotic Resistance in Commensal Escherichia Coli among the Children in Rural Hill Communities of North East India

2018 ◽  
Author(s):  
Ashish Kumar Singh ◽  
Saurav Das ◽  
Samer Singh ◽  
Varsha Rani Gajamer ◽  
Nilu Pradhan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Demographic Factors ◽  
Commensal Bacteria ◽  
School Level ◽  
Resistance Pattern ◽  
Antibiotic Resistant ◽  
E Coli ◽  
North East ◽  
High Prevalence

AbstractCommensal bacteria are the representative of the reservoir of antibiotic resistance genes present in a community. Merely a few community-based studies on the prevalence of antibiotic resistance in commensal bacteria have been conducted so far in Southeast Asia and other parts of India. Northeastern India is still untapped regarding the surveillance of antibiotic-resistant genes and prevalence in commensal bacteria. In the present work, the prevalence of antibiotic resistance in commensal Escherichia coli was investigated along with the associated demographic factors in pre-school and school going children in rural areas of Sikkim. A total of 550 fecal E. coli isolates were obtained from children of the age 1-14 years living in different villages at various altitudes of Sikkim from July 2015 to June 2017. Standard antibiotic susceptibility testing of these isolates was performed. A structured questionnaire was designed to study the factors associated with carriage of antibiotic resistance in commensal E. coli isolates among children. Descriptive statistics analysis and a logistic regression model were used to identify the effect of external factors on antibiotic resistance pattern. High prevalence of resistance was found against commonly used antibiotics ampicillin (92%), ceftazidime (90%), cefoxitin (88%), streptomycin (40%) and tetracycline (36%) among the samples examined in our present study. No resistance to chloramphenicol was recorded. Fifty-two percent of the isolates were resistant to the combination of penicillin and quinolone group of antibiotics. Children living in nuclear families showed higher incidence of resistance to ampicillin (63.15%, OR 0.18,95% CI:0.11 – 0.28, p<0.01) while children of mothers having education up to school level displayed higher incidence of ceftazidime (59.27% OR 0.75, 95% CI:0.55 - 1.02, p<0.02). Our study demonstrates a high prevalence of antibiotic-resistant commensal E. coli against the commonly used antibiotics among children in the study area. A close association between different demographic factors and the pattern of carriage of antibiotic-resistant isolates was observed suggesting a concern over misuse of antibiotics and warrants a future threat of emerging multidrug resistant isolates.

scholarly journals High prevalence of antibiotic resistance in commensal Escherichia coli from healthy human sources in community settings

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Emmanuel Nji ◽  
Joseph Kazibwe ◽  
Thomas Hambridge ◽  
Carolyn Alia Joko ◽  
Amma Aboagyewa Larbi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Enteric Bacteria ◽  
Resistant Bacteria ◽  
Hospital Inpatient ◽  
Community Settings ◽  
Health Crisis ◽  
E Coli ◽  
Healthy Humans ◽  
High Prevalence

AbstractAntibiotic resistance is a global health crisis that requires urgent action to stop its spread. To counteract the spread of antibiotic resistance, we must improve our understanding of the origin and spread of resistant bacteria in both community and healthcare settings. Unfortunately, little attention is being given to contain the spread of antibiotic resistance in community settings (i.e., locations outside of a hospital inpatient, acute care setting, or a hospital clinic setting), despite some studies have consistently reported a high prevalence of antibiotic resistance in the community settings. This study aimed to investigate the prevalence of antibiotic resistance in commensal Escherichia coli isolates from healthy humans in community settings in LMICs. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we synthesized studies conducted from 1989 to May 2020. A total of 9363 articles were obtained from the search and prevalence data were extracted from 33 articles and pooled together. This gave a pooled prevalence of antibiotic resistance (top ten antibiotics commonly prescribed in LMICs) in commensal E. coli isolates from human sources in community settings in LMICs of: ampicillin (72% of 13,531 isolates, 95% CI: 65–79), cefotaxime (27% of 6700 isolates, 95% CI: 12–44), chloramphenicol (45% of 7012 isolates, 95% CI: 35–53), ciprofloxacin (17% of 10,618 isolates, 95% CI: 11–25), co-trimoxazole (63% of 10,561 isolates, 95% CI: 52–73), nalidixic acid (30% of 9819 isolates, 95% CI: 21–40), oxytetracycline (78% of 1451 isolates, 95% CI: 65–88), streptomycin (58% of 3831 isolates, 95% CI: 44–72), tetracycline (67% of 11,847 isolates, 95% CI: 59–74), and trimethoprim (67% of 3265 isolates, 95% CI: 59–75). Here, we provided an appraisal of the evidence of the high prevalence of antibiotic resistance by commensal E. coli in community settings in LMICs. Our findings will have important ramifications for public health policy design to contain the spread of antibiotic resistance in community settings. Indeed, commensal E. coli is the main reservoir for spreading antibiotic resistance to other pathogenic enteric bacteria via mobile genetic elements.

scholarly journals A novel combination of Class-I fumarases and metabolites (α-ketoglutarate and fumarate) signal the DNA damage response in E. coli

2020 ◽  
Author(s):  
Yardena Silas ◽  
Esti Singer ◽  
Norbert Lehming ◽  
Ophry Pines
Keyword(s):  
Dna Damage ◽  
Dna Damage Response ◽  
Dna Damage Repair ◽  
Class Ii ◽  
Class I ◽  
Repair Enzyme ◽  
E Coli ◽  
Damage Repair ◽  
Damage Response

AbstractClass-II fumarases (Fumarate Hydratase, FH) are dual targeted enzymes, occurring in the mitochondria and cytosol of all eukaryotes. They are essential components in the DNA damage response (DDR) and more specifically, protecting cells from DNA double strand breaks. Similarly, the Gram-positive Bacterium Bacillus subtilis Class-II fumarase, in addition to its role in the TCA cycle, also participates in the DDR. Escherichia coli, harbors three fumarase genes; Class-I fumA and fumB and Class-II fumC. Notably, Class-I fumarases, show no sequence similarity to Class-II fumarases and are of different evolutionary origin. Strikingly, here we show that E. coli fumarase functions are distributed between Class-I fumarases which participate in the DDR, and the Class-II fumarase which participates in respiration. In E. coli, we discover that the signaling molecule, alpha-ketoglutarate (α-KG), has a novel function, complementing DNA damage sensitivity of fum null mutants. Excitingly, we identify the E. coli α-KG dependent DNA repair enzyme AlkB, as the target of this interplay of metabolite signaling. In addition to α-KG, fumarate (fumaric acid) is shown to affect DNA damage repair on two different levels, first by directly inhibiting the DNA damage repair enzyme AlkB demethylase activity, both in vitro and in vivo (countering α-KG). The second is a more global effect on transcription, as fum null mutants exhibit a decrease in transcription of key DNA damage repair genes. Together these results show evolutionary adaptable metabolic signaling of the DDR in which fumarases and different metabolites are recruited regardless of the evolutionary enzyme Class preforming the function.Significance StatementClass-II fumarases have been shown to participate in cellular respiration and the DNA damage response. Here we show, for the first time, that in the model prokaryote,Escherichia coli, which harbors both Class-I and Class-II fumarases, it is the Class-I fumarases that participate in DNA damage repair by a mechanism which is different than those described for other fumarases. Strikingly, this mechanism employs a novel signaling molecule, alpha-ketoglutarate (α-KG), and its target is the DNA damage repair enzyme AlkB. In addition, we show that fumarase precursor metabolites, fumarate and succinate, can inhibit the α-KG-dependent DNA damage repair enzyme, AlkB, both in vitro and in vivo. This study provides a new perspective on the function and evolution of metabolic signaling.

scholarly journals Diversity of Hemagglutination Phenotypes among P-Fimbriated Wild-Type Strains of Escherichia coli in Relation to papG Allele Repertoire

1998 ◽  
Vol 5 (2) ◽  
pp. 160-170 ◽  
Author(s):  
James R. Johnson ◽  
Jennifer J. Brown ◽  
Parvia Ahmed
Keyword(s):  
Escherichia Coli ◽  
Phenotypic Diversity ◽  
Class Ii ◽  
Class I ◽  
Class Iii ◽  
Wild Type ◽  
Sheep Erythrocytes ◽  
E Coli ◽  
Naturally Occurring ◽  
Type Strains

ABSTRACT Data regarding the hemagglutination (HA) patterns of the three variants (classes I, II, and III) of the Escherichia coliadhesin PapG are conflicting. These HA patterns usually have been assessed for each papG allele separately with recombinant strains in slide HA assays. We rigorously evaluated an alternative microtiter tray HA assay and then used it to assess the HA of four erythrocyte types (human A1P1 and OP1, rabbit, and sheep erythrocytes) by multiple wild-typeE. coli strains representing the four naturally occurring combinations of the papG alleles, i.e., class I plus III, class III only, class II plus III, and class II only. The microtiter tray HA assay displayed significantly better reproducibility of intraobserver (83%) and interobserver (86%) results than did slide HA assays (39 and 73%, respectively). Novel findings from the study of 32 wild-type P-fimbriated strains included reproducible determinations of phenotypic diversity among different papG categories, among strains within each papG category, and from day to day for individual strains. There was also substantial overlap of phenotypes between papG categories I plus III and III only and between II plus III and II only. A class III papG recombinant strain’s HA pattern differed significantly from that of the wild-type class III strains. These data demonstrate that HA phenotypes of wild-type P-fimbriated E. coli strains can be reproducibly assessed by a microtiter HA assay and that they correspond broadly topapG genotype but in a more complex and varied fashion than previously recognized.

Electron microscopy analysis of degenerating pancreatic ß cells in transgenic mice expressing the MHC Class I antigen Dd

1990 ◽  
Vol 48 (3) ◽  
pp. 548-549
Author(s):  
T. A. Stewart ◽  
D. Liggitt ◽  
S. Pitts ◽  
L. Martin ◽  
M. Siegel ◽  
...  
Keyword(s):  
Type I Diabetes ◽  
Disease Process ◽  
Class Ii ◽  
Class I ◽  
Type I ◽  
Aberrant Expression ◽  
Mhc Molecules ◽  
Endogenous Insulin ◽  
Class Ii Mhc ◽  
Ifn Γ

Insulin-dependant (Type I) diabetes mellitus (IDDM) is a metabolic disorder resulting from the lack of endogenous insulin secretion. The disease is thought to result from the autoimmune mediated destruction of the insulin producing ß cells within the islets of Langerhans. The disease process is probably triggered by environmental agents, e.g. virus or chemical toxins on a background of genetic susceptibility associated with particular alleles within the major histocompatiblity complex (MHC). The relation between IDDM and the MHC locus has been reinforced by the demonstration of both class I and class II MHC proteins on the surface of ß cells from newly diagnosed patients as well as mounting evidence that IDDM has an autoimmune pathogenesis. In 1984, a series of observations were used to advance a hypothesis, in which it was suggested that aberrant expression of class II MHC molecules, perhaps induced by gamma-interferon (IFN γ) could present self antigens and initiate an autoimmune disease. We have tested some aspects of this model and demonstrated that expression of IFN γ by pancreatic ß cells can initiate an inflammatory destruction of both the islets and pancreas and does lead to IDDM.

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