pathogenic escherichia coli
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Pedosphere ◽  
2022 ◽  
Vol 32 (3) ◽  
pp. 495-502
João Pedro Rueda FURLAN ◽  
Inara Fernanda Lage GALLO ◽  
Eliana Guedes STEHLING

Alexandre Loukanov ◽  
Ayano Kuribara ◽  
Svetla Nikolova ◽  
Masakazu Saito

2022 ◽  
Vol 10 (1) ◽  
pp. 121
Laura Fuhrmann ◽  
Wilfried Vahjen ◽  
Jürgen Zentek ◽  
Ronald Günther ◽  
Eva-Maria Saliu

Due to the global spread of antibiotic resistance, there is a strong demand to replace antimicrobial growth promotors in livestock. To identify suitable additives that inhibit the growth of avian pathogenic Escherichia coli O1/O18 and Salmonella enterica serotype Enteritidis strains, an ex vivo screening was performed. Inulin and fructooligosaccharides (FOS) were investigated as prebiotics. Enterococcus faecium and Bacillus coagulans served as probiotic strains. Firstly, the pathogen was anaerobically incubated in caecal digesta from different broiler breeder flocks with the addition of feed additives. Secondly, subsamples of these suspensions were incubated in an antibiotic medium for selective growth of the pathogen. During this step, turbidity was recorded, and lag times were calculated for each pathogen as readout of growth inhibition. Combinations of E. faecium with inulin or FOS significantly extended the lag time for E. coli compared to control. Moreover, older age was a significant factor to enhance this inhibitory effect. In contrast, the combination of FOS and B. coagulans showed shorter lag times for S. Enteritidis. Our results indicate that the E. faecium strain with prebiotics may inhibit the pathogen proliferation in the studied poultry flocks. Furthermore, our results suggest that prophylactic treatments should be assigned by feed additive, age and animal origin.

2022 ◽  
Vol 162 ◽  
pp. 105313
Dharanesha Narasinakuppe Krishnegowda ◽  
Bhoj Raj Singh ◽  
Asok Kumar Mariappan ◽  
Palanivelu Munuswamy ◽  
Karam Pal Singh ◽  

2022 ◽  
pp. 105389
Hafiz Iftikhar Hussain ◽  
Zahid Iqbal ◽  
Mujahid Iqbal ◽  
Xiuhua Kuang ◽  
Yulian Wang ◽  

2022 ◽  
Vol 204 (1) ◽  
Calum M. Webster ◽  
Ayrianna M. Woody ◽  
Safura Fusseini ◽  
Louis G. Holmes ◽  
Gary K. Robinson ◽  

AbstractIt is well known that loss of aerobic respiration in Gram-negative bacteria can diminish the efficacy of a variety of bactericidal antibiotics, which has lead to subsequent demonstrations that the formation of reactive oxygen species (ROS) and the proton motive force (PMF) can both play a role in antibiotic toxicity. The susceptibility of Gram-negative bacteria to aminoglycoside antibiotics, particularly gentamicin, has previously been linked to both the production of ROS and the rate of antibiotic uptake that is mediated by the PMF, although the relative contributions of ROS and PMF to aminoglycoside toxicity has remained poorly understood. Herein, gentamicin was shown to elicit a very modest increase in ROS levels in an aerobically grown Escherichia coli clinical isolate. The well-characterised uncoupler 2,4-dinitrophenol (DNP) was used to disrupt the PMF, which resulted in a significant decrease in gentamicin lethality towards E. coli. DNP did not significantly alter respiratory oxygen consumption, supporting the hypothesis that this uncoupler does not increase ROS production via elevated respiratory oxidase activity. These observations support the hypothesis that maintenance of PMF rather than induction of ROS production underpins the mechanism for how the respiratory chain potentiates the toxicity of aminoglycosides. This was further supported by the demonstration that the uncoupler DNP elicits a dramatic decrease in gentamicin lethality under anaerobic conditions. Together, these data strongly suggest that maintenance of the PMF is the dominant mechanism for the respiratory chain in potentiating the toxic effects of aminoglycosides.

2021 ◽  
Harold Durango ◽  
Hernando Morales ◽  
Enderson Murillo ◽  
Laura Echeverri ◽  
Natalia Quiroz ◽  

Abstract Avian pathogenic E. coli (APEC), produces an extraintestinal infection in chickens, turkeys, and other types of birds, called colibacillosis, and is considered one of the main causes of economic losses due to morbidity, mortality, and the disposal of poultry carcasses. The objective of the present study was to characterize the genetic profile of the virulence factors of different isolates of avian E. coli in Caloto, Cauca, Colombia. Materials and methods: E. coli was isolated and identified by biochemical tests, from 47 clinical isolates. Subsequently, the DNA was extracted using Chelex. Three multiplex PCRs were designed to amplify 13 virulence factors (iroN, hlyF, iss, iutA, frz, vat, sitA, KpsM, sitD, fimH, pstB, sopB, and uvrY), using primers previously reported for each. The amplification products were verified on agarose gels. Each isolate was classified according to the number of virulence factors: group A (between 10 and 13), group B (between 5 and 9), and group C (4 or less). Conclusion: we were able to identify the presence of a group of virulence factors in clinical isolates of APEC, which allows us to demonstrate that both the frequency and the profile of virulence factors in the isolated strains showed a different profile than the reported by other authors. The virulence genes pstB and fimH were detected in all of our samples, and the iss gene was the one with the lowest frequency. And according to the number of virulence factors, the group A was the most frequent.

2021 ◽  
Vol 10 (1) ◽  
pp. 27
Magdalena Ksiezarek ◽  
Ângela Novais ◽  
Luísa Peixe

Since the discovery of the urinary microbiome, including the identification of Escherichia coli in healthy hosts, its involvement in UTI development has been a subject of high interest. We explored the population diversity and antimicrobial resistance of E. coli (n = 22) in the urogenital microbiome of ten asymptomatic women (representing 50% of the sample tested). We evaluated their genomic relationship with extraintestinal pathogenic E. coli (ExPEC) strains from healthy and diseased hosts, including the ST131 lineage. E. coli prevalence was higher in vaginal samples than in urine samples, and occasionally different lineages were observed in the same individual. Furthermore, B2 was the most frequent phylogenetic group, with the most strains classified as ExPEC. Resistance to antibiotics of therapeutic relevance (e.g., amoxicillin-clavulanate conferred by blaTEM-30) was observed in ExPEC widespread lineages sequence types (ST) 127, ST131, and ST73 and ST95 clonal complexes. Phylogenomics of ST131 and other ExPEC lineages revealed close relatedness with strains from gastrointestinal tract and diseased host. These findings demonstrate that healthy urogenital microbiome is a source of potentially pathogenic and antibiotic resistant E. coli strains, including those causing UTI, e.g., ST131. Importantly, diverse E. coli lineages can be observed per individual and urogenital sample type which is relevant for future studies screening for this uropathogen.

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