Rearrangements of Genetic Material in Escherichia coli As Observed on the Bacteriophage P1 Plasmid

1979 ◽  
Vol 43 (0) ◽  
pp. 1197-1208 ◽  
Author(s):  
W. Arber ◽  
S. Iida ◽  
H. Jutte ◽  
P. Caspers ◽  
J. Meyer ◽  
...  
2020 ◽  
Vol 44 (1) ◽  
Author(s):  
E. L. Mejía-Argueta ◽  
J. G. Santillán-Benítez ◽  
M. M. Canales-Martinez ◽  
A. Mendoza-Medellín

Abstract Background To test the antimicrobial potential of clove essential oil that has been less investigated on antimicrobial-resistant organisms (extended-spectrum β-lactamase-ESBL-producing Escherichia coli), we collected 135 ESBL-producing Escherichia coli strains given that E. coli is the major organism increasingly isolated as a cause of complicated urinary and gastrointestinal tract infections, which remains an important cause of therapy failure with antibiotics for the medical sector. Then, in this study, we evaluated the relationship between the antibacterial potential activity of Syzygium aromaticum essential oil (EOSA) and the expression of antibiotic-resistant genes (SHV-2, TEM-20) in plasmidic DNA on ESBL-producing E. coli using RT-PCR technique. Results EOSA was obtained by hydrodistillation. Using Kirby-Baüer method, we found that EOSA presented a smaller media (mean = 15.59 mm) in comparison with chloramphenicol (mean = 17.73 mm). Thus, there were significant differences (p < 0.0001). Furthermore, EOSA had an antibacterial activity, particularly on ECB132 (MIC: 10.0 mg/mL and MBC: 80.0 mg/mL), and a bacteriostatic effect by bactericidal kinetic. We found that the expression of antibiotic-resistant gene blaTEM-20 was 23.52% (4/17 strains) and no expression of blaSHV-2. EOSA presented such as majority compounds (eugenol, caryophyllene) using the GC–MS technique. Conclusions Plant essential oils and their active ingredients have potentially high bioactivity against a different target (membranes, cytoplasm, genetic material). In this research, EOSA might become an important adjuvant against urinary and gastrointestinal diseases caused by ESBL-producing E. coli.


2010 ◽  
Vol 78 (9) ◽  
pp. 4068-4076 ◽  
Author(s):  
Jennifer Hwang ◽  
Lisa M. Mattei ◽  
Laura G. VanArendonk ◽  
Philip M. Meneely ◽  
Iruka N. Okeke

ABSTRACT Enteroaggregative Escherichia coli (EAEC) strains are important diarrheal pathogens. EAEC strains are defined by their characteristic stacked-brick pattern of adherence to epithelial cells but show heterogeneous virulence and have different combinations of adhesin and toxin genes. Pathoadaptive deletions in the lysine decarboxylase (cad) genes have been noted among hypervirulent E. coli subtypes of Shigella and enterohemorrhagic E. coli. To test the hypothesis that cad deletions might account for heterogeneity in EAEC virulence, we developed a Caenorhabditis elegans pathogenesis model. Well-characterized EAEC strains were shown to colonize and kill C. elegans, and differences in virulence could be measured quantitatively. Of 49 EAEC strains screened for lysine decarboxylase activity, 3 tested negative. Most notable is isolate 101-1, which was recovered in Japan, from the largest documented EAEC outbreak. EAEC strain 101-1 was unable to decarboxylate lysine in vitro due to deletions in cadA and cadC, which, respectively, encode lysine decarboxylase and a transcriptional activator of the cadAB genes. Strain 101-1 was significantly more lethal to C. elegans than control strain OP50. Lethality was attenuated when the lysine decarboxylase defect was complemented from a multicopy plasmid and in single copy. In addition, restoring lysine decarboxylase function produced derivatives of 101-1 deficient in aggregative adherence to cultured human epithelial cells. Lysine decarboxylase inactivation is pathoadapative in an important EAEC outbreak strain, and deletion of cad genes could produce hypervirulent EAEC lineages in the future. These results suggest that loss, as well as gain, of genetic material can account for heterogeneous virulence among EAEC strains.


Virology ◽  
1977 ◽  
Vol 80 (2) ◽  
pp. 233-248 ◽  
Author(s):  
S. Zabrovitz ◽  
N. Segev ◽  
G. Cohen

mBio ◽  
2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Fernando Baquero ◽  
Raquel Tobes

ABSTRACT A recent study published in mBio [Y. H. Grad et al., mBio 4(1):e00452-12, 2013] indicates that a rapid introgressive evolution has occurred in Escherichia coli O104:H4 by sequential acquisition of foreign genetic material involving pathogenicity traits. O104 genetic promiscuity cannot be readily explained by high population sizes. However, extensive interactions leading to cumulative assemblies of pathogenicity genes might be assured by small K-strategist populations exploiting particular intestinal niches. Next-generation sequencing technologies will be critical to detect particular “gene cocktails” as potentially pathogenic ensembles and to predict the risk of future outbreaks.


Virology ◽  
1981 ◽  
Vol 114 (2) ◽  
pp. 333-342 ◽  
Author(s):  
N. Segev ◽  
G. Cohen

1988 ◽  
Vol 34 (2) ◽  
pp. 190-193 ◽  
Author(s):  
James J. Germida ◽  
George G. Khachatourians

Bacteriophage P1-mediated generalized transduction of Escherichia coli K-12 was assessed in nonsterile soil. Auxotrophic recipient cells (thr−leu−thi−rpsL) were incubated in a sandy and a silty clay loam soil, and the transducing phage lysates from prototrophic strains carrying transposon 10 (Tn10) in either purE or aroL regions were added. At intervals, the bacterial populations derived from the soils were plated on selective-differential media to enumerate prototrophic (thr+, leu+, or Tcr) transductants. Of 100 bacterial isolates obtained on the selective-differential media, 58 (14 thr+; 11, leu+; 33 Tcr) were confirmed E. coli transductants. The frequency of transduction in soil was ca. 10−6. These data demonstrate the potential use of bacteriophage P1 to genetically manipulate E. coli in situ.


2003 ◽  
Vol 48 (6) ◽  
pp. 1621-1631 ◽  
Author(s):  
Anne-Marie Hansen ◽  
Hansjörg Lehnherr ◽  
Xiandong Wang ◽  
Victoria Mobley ◽  
Ding Jun Jin

1999 ◽  
Vol 65 (5) ◽  
pp. 1843-1848 ◽  
Author(s):  
Glynis L. Kolling ◽  
Karl R. Matthews

ABSTRACT Membrane vesicles released by Escherichia coli O157:H7 into culture medium were purified and analyzed for protein and DNA content. Electron micrographs revealed vesicles that are spherical, range in size from 20 to 100 nm, and have a complete bilayer. Analysis of vesicle protein by sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrates vesicles that contain many proteins with molecular sizes similar to outer membrane proteins and a number of cellular proteins. Immunoblot (Western) analysis of vesicles suggests the presence of cell antigens. Treatment of vesicles with exogenous DNase hydrolyzed surface-associated DNA; PCR demonstrated that vesicles contain DNA encoding the virulence genes eae,stx1 and stx2, and uidA, which encodes for β-galactosidase. Immunoblot analysis of intact and lysed, proteinase K-treated vesicles demonstrate that Shiga toxins 1 and 2 are contained within vesicles. These results suggest that vesicles contain toxic material and transfer experiments demonstrate that vesicles can deliver genetic material to other gram-negative organisms.


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