scholarly journals In Silico Prediction and Design of Uropathogenic Escherichia coli Alpha-Hemolysin Generate a Soluble and Hemolytic Recombinant Toxin

2022 ◽  
Vol 10 (1) ◽  
pp. 172
Author(s):  
Bruna De Lucca Caetano ◽  
Marta de Oliveira Domingos ◽  
Miriam Aparecida da Silva ◽  
Jessika Cristina Alves da Silva ◽  
Juliana Moutinho Polatto ◽  
...  

The secretion of α-hemolysin by uropathogenic Escherichia coli (UPEC) is commonly associated with the severity of urinary tract infections, which makes it a predictor of poor prognosis among patients. Accordingly, this toxin has become a target for diagnostic tests and therapeutic interventions. However, there are several obstacles associated with the process of α-hemolysin purification, therefore limiting its utilization in scientific investigations. In order to overcome the problems associated with α-hemolysin expression, after in silico prediction, a 20.48 kDa soluble α-hemolysin recombinant denoted rHlyA was constructed. This recombinant is composed by a 182 amino acid sequence localized in the aa542–723 region of the toxin molecule. The antigenic determinants of the rHlyA were estimated by bioinformatics analysis taking into consideration the tertiary form of the toxin, epitope analysis tools, and solubility inference. The results indicated that rHlyA has three antigenic domains localized in the aa555–565, aa600–610, and aa674–717 regions. Functional investigation of rHlyA demonstrated that it has hemolytic activity against sheep red cells, but no cytotoxic effect against epithelial bladder cells. In summary, the results obtained in this study indicate that rHlyA is a soluble recombinant protein that can be used as a tool in studies that aim to understand the mechanisms involved in the hemolytic and cytotoxic activities of α-hemolysin produced by UPEC. In addition, rHlyA can be applied to generate monoclonal and/or polyclonal antibodies that can be utilized in the development of diagnostic tests and therapeutic interventions.

2019 ◽  
Vol 19 (3) ◽  
pp. 322-326 ◽  
Author(s):  
Hassan Valadbeigi ◽  
Elham Esmaeeli ◽  
Sobhan Ghafourian ◽  
Abbas Maleki ◽  
Nourkhoda Sadeghifard

Introduction: The aim of the current study was to investigate the prevalence of virulence genes in uropathogenic Escherichia coli (UPEC) isolates in Ilam. Materials and Methods: For this purpose, a total of 80 UPEC isolates were collected for patients with UTIs during a 6 months period. The multiplex polymerase chain reaction (multiplex PCR) was used to detect the papEF, fimH, iucD, hlyA, fyuA, and ompT genes. Results: The prevalence of fimH, papEF, iucD, fyuA, hlyA, hlyA, and ompT genes were 87.5%, 47.5%, 60%, 67.5%, 27.5%, 47.5% and 71.2%, respectively. Among all of the isolates, 27 profiles were obtained. Conclusion: Our findings demonstrated that the most prevalence was found for fimH, and different distribution of virulence genes suggested different ability of pathogenicity.


Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1348
Author(s):  
Lívia Slobodníková ◽  
Barbora Markusková ◽  
Michal Kajsík ◽  
Michal Andrezál ◽  
Marek Straka ◽  
...  

Urinary tract infections (UTIs) are among the events that most frequently need medical intervention. Uropathogenic Escherichia coli are frequently their causative agents and the infections are sometimes complicated by the presence of polyresistant nosocomial strains. Phage therapy is a tool that has good prospects for the treatment of these infections. In the present study, we isolated and characterized two bacteriophages with broad host specificity against a panel of local uropathogenic E. coli strains and combined them into a phage cocktail. According to genome sequencing, these phages were closely related and belonged to the Tequatrovirus genus. The newly isolated phages showed very good activity on a panel of local clinical E. coli strains from urinary tract infections. In the form of a two-phage cocktail, they were active on E. coli strains belonging to phylogroups B2 and D, with relatively lower activity in B1 and no response in phylogroup A. Our study is a preliminary step toward the establishment of a national phage bank containing local, well-characterized phages with therapeutic potential for patients in Slovakia.


2010 ◽  
Vol 5 (6) ◽  
pp. 827-830
Author(s):  
Georgi Slavchev ◽  
Nadya Markova

AbstractUropathogenic strains of E. coli isolated from urine of patients with urinary tract infections were tested for antibiotic sensitivity using bio-Merieux kits and ATB-UR 5 expression system. The virulence of strains was evaluated by serum bactericidal assay, macrophage “killing” and bacterial adhesive tests. Survival capability of strains was assessed under starvation in saline. The results showed that quinolone-resistant uropathogenic strains of E. coli exhibit significantly reduced adhesive potential but relatively high resistance to serum and macrophage bactericidity. In contrast to laboratory strains, the quinolone-resistant uropathogenic clinical isolate demonstrated increased viability during starvation in saline. Our study suggests that quinolone-resistant uropathogenic strains are highly adaptable clones of E. coli, which can exhibit compensatory viability potential under unfavorable conditions. The clinical occurrence of such phenotypes is likely to contribute to the survival, persistence and spread strategy of resistant bacteria.


Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1072
Author(s):  
Alfredo Montes-Robledo ◽  
Rosa Baldiris-Avila ◽  
Johan Fabian Galindo

FimH is a type I fimbria of uropathogenic Escherichia coli (UPEC), recognized for its ability to adhere and infect epithelial urinary tissue. Due to its role in the virulence of UPEC, several therapeutic strategies have focused on the study of FimH, including vaccines, mannosides, and molecules that inhibit their assembly. This work has focused on the ability of a set of monosubstituted and disubstituted phenyl mannosides to inhibit FimH. To determine the 3D structure of FimH for our in silico studies, we obtained fifteen sequences by PCR amplification of the fimH gene from 102 UPEC isolates. The fimH sequences in BLAST had a high homology (97–100%) to our UPEC fimH sequences. A search for the three-dimensional crystallographic structure of FimH proteins in the PDB server showed that proteins 4X5P and 4XO9 were found in 10 of the 15 isolates, presenting a 67% influx among our UPEC isolates. We focused on these two proteins to study the stability, free energy, and the interactions with different mannoside ligands. We found that the interactions with the residues of aspartic acid (ASP 54) and glutamine (GLN 133) were significant to the binding stability. The ligands assessed demonstrated high binding affinity and stability with the lectin domain of FimH proteins during the molecular dynamic simulations, based on MM-PBSA analysis. Therefore, our results suggest the potential utility of phenyl mannoside derivatives as FimH inhibitors to mitigate urinary tract infections produced by UPEC; thus, decreasing colonization, disease burden, and the costs of medical care.


2010 ◽  
Vol 2 (02) ◽  
pp. 070-073 ◽  
Author(s):  
K Prabhat Ranjan ◽  
Neelima Ranjan ◽  
Arindam Chakraborty ◽  
D R Arora

ABSTRACT Purpose: To study the occurrence and characterization of Uropathogenic Escherichia coli (UPEC) in cases with urinary tract infections. Materials and Methods: A total of 220 symptomatic cases from urinary tract infections and 50 stool samples from apparently healthy individuals were included. The colonies identified as Escherichia coli were screened for virulence factors, that is, hemolysin, Mannose Resistant and Mannose Sensitive Hemagglutination (MRHA, MSHA), Cell surface hydrophobicity, and Serum resistance. Results: Among the 220 cases 91 (41.36%) were hemolytic, 68 (30.90%) showed MRHA, 58 (26.36%) were cell surface hydrophobicity positive, and 72 (32.72%) were serum-resistant. In 50 controls, three (6%) were hemolytic, six (12%) showed MRHA, nine (18%) showed cell surface hydrophobicity, and 12 (24%) were serum-resistant. The difference between cases and controls for hemolysis and MRHA were significant (P<0.001 and P<0.01, respectively). A total of 14 atypical E. coli were isolated from the urine and all showed the presence of one or the other virulence markers. Out of the 18 mucoid E.coli isolated, 10 were serum-resistant. Conclusions: The present study revealed that out of 220 urinary isolates, 151 could be labeled as UPEC.


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